1
Classes of Polymeric Materials
Professor Joe Greene
CSU, CHICO
2
Topics
• Introduction
• Thermoplastics
– General
– Commercial plastics
• Thermosets
– General
– Commercial thermosets
• Elastomers
– General
– Commercial elastomers
3
Introduction
• Polymeric materials can be either– Thermoplastics, thermosets, and elastomers.
– Each section is presented in appropriate groups
• Thermoplastics come in a variety of forms
– Pellets, powder (1-100 microns), flake, chip, cube, dice,
– Shipped in packages of choice
– Bags (50 lbs), drums (200 lbs), boxes, cartons, gaylords (1000 lb),
– Tank-truck loads (15 tons), rail cars (40 – 80 tons)
• Bulk supplies are stored in silos and conveyed pneumatically
• Thermosets are supplied in powder or liquid form
– Supplied in drums, tank-trucks, and railroad cars.
• Rubbers are supplied in bale form.
4
Commercial Thermoplastics • Olefins
– Unsaturated, aliphatic hydrocarbons made from ethylene gas
– Ethylene is produced by cracking higher hydrocarbons of natural gas or petroleum
• LDPE commercialized in 1939 in high pressure process
• Branched, high pressure, and low density polyethylene
• HDPE commercialized in 1957 in low pressure process
• Linear, low pressure, high density
• The higher the density the higher the crystallinity
• Higher the crystallinity the higher the modulus, strength, chemical resistance,
• PE grades are classified according to melt index (viscosity) which is a strong indicator of molecular weight.
– Injection molding requires high flow, extrusion grade is highly elastic, thermoforming grade requires high viscosity or consistency
5
Principal Olefin Monomers• Ethylene Propylene
• Butene-1 4-Methylpentene
C C
H H
H H
C C
C2H5 H
H H
C C
CH3 H
H H
C C
C5H6 H
H H
CH3
6
Several Olefin Polymers• Polyethylene Polypropylene
• Polyisobutene Polymethylpentene
C C
C5H6 H
H H
CH3
n
C C
H H
H H
n
C C
C2H5 H
H H
n
C C
CH3 H
H H
n
7
Polymers Derived from Ethylene Monomer
X Position Material Name AbbreviationH Polyethylene PE
Cl Polyvinyl chloride PVCMethyl group Polypropylene PPBenzene ring Polystyrene PSCN Polyacrylonitrile PAN
OOCCH3 Polyvinyl acetate PvaCOH Polyvinyl alcohol PVACOOCH3 Polymethyl acrylate PMA
F Polyvinyl fluoride PVF
Note:Methyl Group is:
|H – C – H
|H
Benzene ring is:
X Position Y Position Material Name AbbreviationF F Polyvinylidene fluoride PVDF
Cl Cl Polyvinyl dichloride PVDC
CH3 (Methyl group) CH3 Polyisobutylene PB
COOCH3 CH3 Polymethyl methacrylate PMMA
8
Addition Polymerization of PE• Polyethylene produced with low (Ziegler) or high pressure (ICI)
• Polyethylene produced with linear or branched chains
OR
C C
H H
H H
C C
H H
H H
C C
H H
H H
C C
H H
H H
C C
H H
H H
……
C C
H H
H H
C C
H H
H H
C C
H
H H
C C
H H
H H
C C
H H
H H
……
9
Mechanical Properties of Polyethylene
• Type 1: (Branched) Low Density of 0.910 - 0.925 g/cc
• Type 2: Medium Density of 0.926 - 0.940 g/cc
• Type 3: High Density of 0.941 - 0.959 g/cc
• Type 4: (Linear) High Density to ultra high density > 0.959
Mechanical PropertiesBranched LowDensity
MediumDensity
HighDensity
Linear High Density
Density 0.91- 0.925 0.926- 0.94 0.941-0.95 0.959-0.965
Crystallinity 30% to 50% 50% to 70% 70% to 80% 80% to 91%
MolecularWeight
10K to 30K 30K to 50K 50K to 250K 250K to 1.5M
TensileStrength, psi
600 - 2,300 1,200 - 3,000 3,100 - 5,500 5,000 – 6,000
TensileModulus, psi
25K – 41K 38K – 75 K 150K – 158K
150K – 158 K
TensileElongation, %
100% - 650% 100%- 965% 10% - 1300% 10% - 1300%
Impact Strengthft-lb/in
No break 1.0 – nobreak
0.4 – 4.0 0.4 – 4.0
Hardness, Shore D44 – D50 D50 – D60 D60 – D70 D66 – D73
10
Physical Properties of Polyethylene
Physical Properties of polyethylene
Branched Low
Density
Medium Density High
Density
Linear High Density
Optical
Transparent to opaque
Transparent to opaque
Transparent to opaque
Transparent to opaque
Tmelt
98 – 115 C 122 – 124 C 130 – 137 C 130 –137 C
Tg -100 C -100 C -100 C -100 C
H20 Absorption
Low < 0.01 Low < 0.01 Low < 0.01 Low < 0.01
Oxidation
Resistance
Low, oxides
readily
Low, oxides
readily
Low, oxides readily Low, oxides readily
UV Resistance
Low, Crazes
readily
Low, Crazes
readily
Low, Crazes readily Low, Crazes readily
Solvent Resistance
Resistant below 60C
Resistant below 60C
Resistant below 60C Resistant below 60C
Alkaline
Resistance
Resistant Resistant Resistant Resistant
Acid Resistance
Oxidizing Acids
Oxidizing Acids Oxidizing Acids Oxidizing Acids
11
Processing Properties of Polyethylene
Processing Properties
Branched Low
Density
Medium Density High
Density
Linear High Density
Tmelt 98 – 115 C 122 – 124 C 130 – 137 C 130 –137 C
Recommended TempRange
(I:Injection, E:Extrusion)
I: 300F – 450FE: 250F – 450F
I: 300F – 450FE: 250F – 450F
I: 350F – 500FE: 350F – 525F
I: 350F – 500FE: 350F – 525F
Molding Pressure 5 – 15 psi 5 – 15 psi 12 – 15 psi 12– 15 psi
Mold (linear) shrinkage
(in/in)
0.015 – 0.050 0.015 – 0.050 0.015 – 0.040 0.015 – 0.040
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Special Low Versions of PolyethyleneProduced through catalyst selection and regulation of reactor conditions
• Very Low Density Polyethylene (VLDPE)• Densities between 0.890 and 0.915
• Applications include disposable gloves, shrink packages, vacuum cleaner
hoses, tuning, bottles, shrink wrap, diaper film liners, and other health care
products
• Linear Low Density Polyethylene (LLDPE)• Densities between 0.916 and 0.930
• Contains little if any branching by co-polymerizing ethylene at low pressures
in presence of catalysts with small amounts of α-olefin co-monomers
(butene, hexene, octene) which play the role of uniform short branches along
linear backbone.
• Properties include improved flex life, low warpage, improved stress-crack
resistance, better impact, tear, or puncture versus conventional LDPE
• Applications include films for ice, trash, garment, and produce bags at
thinner gage.
13
Special High Versions of PolyethyleneProduced through catalyst selection and regulation of reactor conditions
• Ultra High Molecular Weight Polyethylene (UHMWPE)
– Extremely high MW at least 10 times of HDPE (MW=3M to 6M)
– Process leads to linear molecules with HDPE
– Densities are 0.93 to 0.94 g/cc and Moderate cost
– High MW leads to high degree of physical entanglements that
• Above Tmelt (130 C or 266F), the material behaves in a rubber-like
molecule rather than fluid-like manner causing processing troubles,
high viscosities
• Processed similar to PTFE (Teflon)
– Ram extrusion and compression molding are used.
14
Special High Versions of PolyethyleneProduced through catalyst selection and regulation of reactor conditions
• Ultra High Molecular Weight Polyethylene (UHMWPE)
– Properties include outstanding properties like engineering plastic
or specialty resin
• Chemical inertness is unmatched; environmental stress cracking
resistance and resistance to foods and physiological fluids,
• Outstanding wear or abrasion resistance, very low coefficient of
friction, excellent toughness and impact resistance.
– Applications:
• pump parts, seals, surgical implants, pen tips, and butcher-block
cutting surfaces. , chemical handling equipment, pen tips, prosthetic
wear surfaces, gears
15
Special Forms of Polyethylene• Cross-linked PE (XLPE)
– Chemical cross-links improve chemical resistance and improve
temperature properties.
– Cross-linked with addition of small amounts of organic peroxides
• Dicumyl peroxide, etc.
– Crosslinks a small amount during processing and then sets up after
flowing into mold.
– Used primarily with rotational molding
– Extruded Products
• Films (shrink wrap film in particular)
• Pipes
• Electrical wire and cable insulation
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Copolymers of Polyethylene• Ethylene-Vinyl Acetate (EVA)
– Repeating groups is ethylene with a vinyl acetate functional that reduces the
regularity of the chain; thus the crystallinity and stiffness
– Part of the pendent group are highly polar which makes film with increased water
vapor permeability, increased oil resistance and cling.
– Vinyl acetate reduces crystallinity and increases chemical reactivity because of high
regions of polarity.
– Applications include flexible packaging, shrink wrap, auto bumper pads, flexible
toys, and tubing with vinylacetate up to 50%
C C
H H
H H
C C
H O
C = O
C
H H
n m
17
Copolymers of Polyethylene• Ethylene-vinyl alcohol (EVOH)
• Contains equal amounts of two repeat units that act as
– Barrier layers or as interlayers (tie layers) between incompatible
materials due to strong bonding of vinylalcohol repeat units.
• Ethylene-ethyl acrylate (EEA) Ethylene-methyl acrylate (EMA)
• Properties range from rubbery to tough ethylene-like properties
• Applications include hot melt adhesives, shrink wrap, produce bags,
bag-in-box products, and wire coating.
• Produced by addition of methyl acrylate monomer (40% by weight)
with ethylene gas
– reduces crystallinity and increases polarity
• Tough, thermally stable olefin with good rubber characteristics.
• Applications include food packaging, disposable medical gloves,
heat-sealable layers, and coating for composite packaging
18
Copolymers of Polyethylene• Ethylene-carboxylic acid (EAA, EMAA)
– Small amounts of acrylic acid (AA) or methacrylic acid (MAA) that feature
carboxyl acid groups (COOH) are notable adhesives, especially to polar
substrates, including fillers and reinforcements
– Problems include tackiness and corrosive to metals and crosslinking nature
• Ionomers
– Modified ethylene-methacrylic acid copolymers where some of the carboxyl
acid groups are converted into corresponding metallic salts (metal metacrylate),
where the metals are sodium or zinc.
– Ionic bonds are formed between these cationic and the remaining anionic acid
groups. Results in a quasi crosslinked polymer at low temperature and is
reversible at high temperature
– Useful properties, e.g., adhesive and paints to metals (polarity), resistance to
fats and oils, Flex, puncture, impact resistance
– Applications: golf balls, bowling pin covers, ski boot shells, films
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Copolymers of Polyethylene• Ethylene-Propylene (EPM)
– Ethylene and propylene are copolymerized in random manner and causes a delay
in the crystallization.
– Thus, the copolymer is rubbery at room temp because the Tg is between HDPE
(-110C) and PP (-20C).
– Ethylene and propylene can be copolymerized with small amounts of a
monomer containing 2 C=C double bonds (dienes)
– Results in a co-polymer, EPR, or thermoplastic rubber, TPR
C C
H H
H H
n
C C
CH3 H
H H
m
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Mechanical Properties of PE Blends
Mechanical Properties of PE BlendsEthylene-vinyl
acetate
Ethylene-vinyl
alcohol
Ethylene-
ethyl acrylate
Ethylene-methyl
acrylate
Density 0.922 – 0.943 1.14 – 1.19 0.93 0.942 – 0.945
TensileStrength, psi
2,200 – 4,000 8,520 – 11,600 1,600 – 2,100 1,650
TensileModulus, psi
7K – 29K 300 K – 385 K 4K – 7.5 K 12 K
Tensile
Elongation, %
300% - 750% 180%- 280% 700% - 750% 740%
Impact Strengthft-lb/in
No break 1.0 – 1.7 No break
Hardness, Shore D17 – D45 D27 – D38
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Processing Properties of PE Blends
Processing Properties
Ethylene-vinyl
acetate
Ethylene-vinyl
alcohol
Ethylene-ethyl
acrylate
Ethylene-methyl
acrylate
Tmelt 103 – 108 C 142 – 181 C 83 C
Recommended TempRange (C: Compression)
(I:Injection, E:Extrusion)
C: 200-300FI: 300F – 430F
E: 300F – 380F
I: 365F – 480FE: 365F – 480F
C: 200 – 300FI: 250F – 500F
E: 300F – 620F
Molding Pressure 1 – 20 psi 1 – 20 psi
Mold (linear) shrinkage
(in/in)
0.007 – 0.035 0.015 – 0.035
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Polypropylene History
• Prior to 1954 most attempts to produce plastics from
polyolefins had little commercial success
– PP invented in 1955 by Italian Scientist F.J. Natta by addition
reaction of propylene gas with a sterospecific catalyst titanium
trichloride.
– Isotactic polypropylene was sterospecific (molecules are
arranged in a definite order in space)
– PP is not prone to environmental stress-cracking like PE
• Polypropylene is similar in manufacturing method and in
properties to PE
• Tg of PP = -25C versus Tg of PE of -100C
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Chemical Structure
• Propylene
• Isotactic- CH3 on one side of polymer chain (isolated).Commercial PP is 90% to 95% Isotactic
C C
CH3 H
H H
C C
CH3 H
H H
C C
CH3 H
H H
C C
CH3 H
H H
C C
CH3 H
H H
C C
CH3 H
H H
n
24
Polypropylene Stereostatic Arrangements
•Atactic- CH3 in a random order (A- without; Tactic- order) Rubbery and of
limited commercial value.
•Syndiotactic- CH3 in a alternating order (Syndio- ; Tactic- order)
C C
CH3 H
H H
C C
H H
H CH3
C C
CH3 H
H H
C C
H H
H CH3
C C
CH3 H
H H
C C
CH3 H
H H
C C
H H
H CH3
C C
H H
H CH3
C C
CH3 H
H H
C C
H H
H CH3
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Addition Polymerization of PP• Polypropylene produced with low pressure process (Ziegler)
• Polypropylene produced with linear chains
• Polypropylene is similar in manufacturing method and in properties to
PE
• Differences between PP and PE are
– Density: PP = 0.90; PE = 0.941 to 0.965
– Melt Temperature: PP = 176 C; PE = 110 C
– Tg of PP = -25C versus Tg of PE of -100C
– Service Temperature: PP has higher service temperature
– Hardness: PP is harder, more rigid, and higher brittle point
– Stress Cracking: PP is more resistant to environmental stress cracking
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Advantages/Disadvatages of Polypropylene• Advantages
– Low Cost
– Excellent flexural strength
– Good impact strength
– Processable by all thermoplastic
equipment
– Low coefficient of friction
– Excellent electrical insulation
– Good fatigue resistance
– Excellent moisture resistance
– Service Temperature to 126 C
– Very good chemical resistance
• Disadvantages– High thermal expansion
– UV degradation
– Poor weathering resistance
– Subject to attack by chlorinated
solvents and aromatics
– Difficulty to bond or paint
– Oxidizes readily
– flammable
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Mechanical Properties of Polypropylene
Mechanical Properties of PolypropylenePolypropylene LDPE
(For Comparison)HDPE(For Comparison)
Density 0.90 0.91- 0.925 0.959-0.965
Crystallinity 30% to 50% 30% to 50% 80% to 91%
Molecular Weight 200K to 600K 10K to 30K 250K to 1.5M
Molecular Weight
Dispersity MWD
(Mw/Mn)
Range ofMWD forprocessing
Range of MWDfor processing
Range of MWDfor processing
Tensile Strength,
psi
4,500 – 5,500 600 - 2,300 5,000 – 6,000
Tensile Modulus,
psi
165K – 225K 25K – 41K 150K – 158 K
Tensile
Elongation, %
100% - 600% 100% - 650% 10% - 1300%
Impact Strengthft-lb/in
0.4 – 1.2 No break 0.4 – 4.0
Hardness, Shore R80 - 102 D44 – D50 D66 – D73
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Physical Properties of Polyethylene
Physical Properties of Polypropylene
Polypropylene LDPE HDPE
Optical Transparent toopaque
Transparent toopaque
Transparent to opaque
Tmelt 175 C 98 – 115 C 130 –137 C
Tg -20 C -100 C -100 C
H20
Absorption
0.01 – 0.03 Low < 0.01 Low < 0.01
Oxidation
Resistance
Low, oxidesreadily
Low, oxidesreadily
Low, oxides readily
UV Resistance Low, Crazesreadily
Low, Crazesreadily
Low, Crazes readily
Solvent
Resistance
Resistant
below 80C
Resistant below
60C
Resistant below 60C
Alkaline
Resistance
Resistant Resistant Resistant
Acid
Resistance
OxidizingAcids
Oxidizing Acids Oxidizing Acids
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Processing Properties of Polyethylene
Processing Properties
Polypropylene LDPE HDPE
Tmelt 175 C 98 – 115 C 130 –137 C
Recommended TempRange
(I:Injection, E:Extrusion)
I: 400F – 550FE: 400F – 500F
I: 300F – 450FE: 250F – 450F
I: 350F – 500FE: 350F – 525F
Molding Pressure 10 -20 psi 5 – 15 psi 12– 15 psi
Mold (linear) shrinkage
(in/in)
0.010 – 0.025 0.015 – 0.050 0.015 – 0.040
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Several Olefin Polymers• Polybutylene (PB)
– Based on butene-1 monomer
– Plus comonomers (small amt)
– Melt Point 125C similar to PE
– Tg, -25C is closer to PP
– Good creep & ESC resistance
– Good for pipe and film extrusions
C C
C2H5 H
H H
n
C C
HCH H
H H
H3C C CH3
n
• Polymethylpentene (PMP)
– Trade name is TPX
– Crystallizes to high degree (60%)
– Highly transparent (90% transmis)
– Properties similar to PP
– Density is 0.83 g/cc, Tg =30C
– Stable to 200C, Tm=240C
– Creep and chemical resistance is good
and low permeability.
– Electrical properties are excellent
– Process by injection & extrusion
– Good for lighting, packaging, trays,
bags, coffee makers, wire covering,
connectors, syringes.
– Poor ESC and UV
H
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Polyolefin_Polybutylene
• History
– PB invented in 1974 by Witco Chemical
– Ethyl side groups in a linear backbone
• Description
– Linear isotactic material
– Upon cooling the crystallinity is 30%
– Post-forming techniques can increase crystallinity to 55%
– Formed by conventional thermoplastic techniques
• Applications (primarily pipe and film areas)
– High performance films
– Tank liners and pipes
– Hot-melt adhesive
– Coextruded as moisture barrier and heat-sealable packages
C C
CH2 H
H H
CH3
32
Properties of Polybutylene
Mechanical Properties of PolybutylenePolybutylene Polypropylene LDPE
(For Comparison)
HDPE
(For Comparison)
Density 0.908 -.917 0.90 0.91- 0.925 0.959-0.965
Crystallinity 30% to 50% 30% to 50% 30% to 50% 80% to 91%
Tensile Strength,
psi
4,000 4,500 – 5,500 600 - 2,300 5,000 – 6,000
Tensile Modulus,
psi
10K – 40K 165K – 225K 25K – 41K 150K – 158 K
Tensile
Elongation, %
300% - 400% 100% - 600% 100% - 650% 10% - 1300%
Impact Strengthft-lb/in
No break 0.4 – 1.2 No break 0.4 – 4.0
Hardness Shore D55 – D65 R80 - 102 D44 – D50 D66 – D73
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Polyolefin_Polymethylpentene (PMP)• Description
– Crystallizes to 40%-60%
– Highly transparent with 90% transmission
– Formed by injection molding and blow molding
• Properties
– Low density of 0.83 g/cc; High transparency
– Mechanical properties comparable to polyolefins with higher temperature
properties and higher creep properties.
– Low permeability to gasses and better chemical resistance
– Attacked by oxidizing agents and light hydrogen carbon solvents
– Attacked by UV and is quite flammable
• Applications
– Lighting elements (Diffusers, lenses reflectors), liquid level
– Food packaging containers, trays, and bags.
C C
CH2 H
H H
H3C-CH-CH3
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Properties of Polymethylpentene
Mechanical Properties of PolymethylpentenePolymethyl-
pentene
Polypropylene LDPE
(For Comparison)
HDPE
(For Comparison)
Density 0.83 0.90 0.91- 0.925 0.959-0.965
Crystallinity 40% to60% 30% to 50% 30% to 50% 80% to 91%
Tensile Strength,
psi
4,000 – 5,000 4,500 – 5,500 600 - 2,300 5,000 – 6,000
Tensile Modulus,
psi
160K – 200K 165K – 225K 25K – 41K 150K – 158 K
Tensile
Elongation, %
100% - 400% 100% - 600% 100% - 650% 10% - 1300%
Impact Strengthft-lb/in
0.4 – 1.0 0.4 – 1.2 No break 0.4 – 4.0
Hardness R80 – R100 R80 - 102 D44 – D50 D66 – D73
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PVC Background • Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB
– Polyvinyls were invented in 1835 by French chemist V. Regnault when he
discovered a white residue could be synthesized from ethylene dichloride in an
alcohol solution. (Sunlight was catalyst)
– PVC was patented in 1933 by BF Goodrich Company in a process that
combined a plasticizer, tritolyl phosphate, with PVC compounds making it
easily moldable and processed.
– PVC is the leading plastic in Europe and second to PE in the US.
– PVC is made by suspension process (82%), by mass polymerization (10% ), or
by emulsion (8%)
– All PVC is produced by addition polymerization from the vinyl chloride
monomer in a head-to-tail alignment.
– PVC is amorphous with partially crystalline (syndiotactic) due to structural
irregularity increasing with the reaction temperature.
– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas
36
PVC and Vinyl Products
• Rigid-PVC
– Pipe for water delivery
– Pipe for structural yard and garden structures
• Plasticizer-PVC or Vinyl– Latex gloves
– Latex clothing
– Paints and Sealers
– Signs
37
PVC and PS Chemical Structure• Vinyl Groups (homopolymers produced by addition polymerization)
– PVC - poly vinylidene - polyvinylalcohol (PVOH)
chloride (PVDC)
– polyvinyl acetate (PVAc) - PolyStyrene (PS)
C C
H Cl
H H
n
C C
H Cl
H Cl
n
C C
H OCOCH3
H H
n
C C
H OH
H H
n
C C
H
H H
n
38
Mechanical Properties of Polyvinyls
Mechanical PropertiesPVC (rigid) PVC (Flexible) PVB PVDC
Density, g/cc 1.30-1.58 1.16-1.35 1.05 1.65-1.72
Tensile Strength,psi
6,000 - 7,500 1,500 -3,500 500 - 3,000 3,500 - 5,000
Tensile Modulus,psi
350K – 600K 160K –240K
TensileElongation, %
40% - 80% 200%-450% 150% - 450% 160% -240%
Impact Strengthft-lb/in
0.4 - 22 Range Range 0.4 - 1
Hardness Shore D65-85 Shore A50-100 M60-65
CLTE
10-6 mm/mm/C
50 -100 70-250 190
HDT 264 psi 140 F -170F 130F -150F
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Physical Properties of Polyvinyls
PVC (rigid) PVC (Flexible) PVB PVDCOptical Transparent Transparent Transparent Transparent
Tmelt 75 – 105 C 75 – 105 C 49 172C
Tg 75 -105C 75-105C 49 -15C
H20
Absorption
0.04-0.4% (24h) 0.15-0.75% (24h) 0.09-0.16% (24h) 0.1% (24h)
Oxidation
Resistance
good good good good
UV Resistance Poor Poor Poor good
Solvent
Resistance
Soluble in
Acetone, andCyclohexanol.Partially in
Toluene
Soluble in
Acetone, andCyclohexanol.Partially in
Toluene
Dissolved in ketones
and esters
good
Alkaline
Resistance
Excellent Excellent Excellent good
Acid
Resistance
good good good good
Cost $/lb $0.27 $0.27 $ $1.62
40
Processing Properties of Polyvinyls
PVC (rigid) PVC (Flexible) PVB PVDCTmelt 75 – 105 C 75 – 105 C 49 172C
Recommended TempRange (I:Injection, E:Extrusion,C: Compression)
I: 300F – 415FC: 285F-400F
I: 320F – 385FC: 285F - 350F
I: 250F – 340FC: 280F-320F
I: 300F – 400FC: 260F-350FE: 300F-400F
Molding Pressure 10-40 kpsi 8-25 kpsi 0.5-3kpsi 5 - 30 kpsi
Mold (linear) shrinkage(in/in)
0.002 – 0.006 0.010 – 0.050 0.005 - 0.025
41
Vinylchloride Co-Polymers• Chlorinated PVC (CPVC)
– Possible to chemically modify PVC by substituting Cl for H
– Cl content can be raised from 56.8% in PVC to 62%-72%
– CPVC has improved chemical and temperature resistance that can be used for pipe and hot water applications, even boiling water.
• Vinylchloride-vinylacetate (PVC-VAC)– Internally plasticizing PVC with 3% to 30% vinyl acetate
– Impact properties and processing ease are improved for
• Floor coverings, phonograph records.
• Polyalloys– Improves impact resistance of rigid PVC by blending with elastomers, e.g.,
EVA, Nitrile rubber (NBR), Chloronated PE.
– Blend PVC with PMMA and SAN for better transparency
– Blend PVC with ABS for improved combustion resistance
42
Vinylchloride Co-Polymers• Polyvinylidenechloride (PVDC)
– Homopolymer can crystallize. Tg = -18C, Tm = 190C
• Decomposition temperature is slightly above melt temperature of abut 200C
• PVDC has outstanding barrier properties for O2, CO2, and H2O.
• Copolymerized with 10-15% vinyl chloride to create Saran Wrap.
• Copolymerize with acrlonitrile and acrylate esters up to 50%.
• Coplymerization reduces crystallinity to 35-45% and the Tmelt ot 175C
• Polyvinyl acetate (PVAC)
– Not used as a plastic
• Noncrystallizing
• Low Tg = 30C, it is
– It is best as a major ingredient in adhesives and paint, Elmers Glue
– Vinylacetate repeat units form the minor component in imporant copolymers
with vinylchloride (PVC-PVAC) and ethylene (EVA)
C C
H Cl
H Cl
n
C C
H OCOCH3
H H
n
43
Vinylchloride Co-Polymers• Polyvinylalcohol (PVAL or PVOH)
– Homopolymer is very polar can crystallize
– Water soluable. Tg = 80C, Tm = 240C
– Random copolymer that is derived from PVAC
– Used as a release film for reinforced plastics or barrier film.
• Polyvinylbutyral (PVB)– Random copolymer (PVB-PVAL)
• containing 10-15% VAL
• Low Tg = 50C
– Used in plasticized form as adhesive interlayer
• For windshield safety glass (Saflex from Monsanto)
• Powder is extruded into sheet and then placed between two layers of glass
– Requires
• Toughness, transparency, weatherability, and adhesion to glass.
C C
H OH
H H
n
C C
H CH2
H H
nCH2CH3
44
PS Background • PS is one of the oldest known vinyl compounds
– PS was produced in 1851 by French chemist M. Berthelot by passing benzene and ethylene through a red-hot-tube (basis for today)
– Amorphous polymer made from addition polymerization of styrene
– Homopolymer (crystal): (2.7 M metric tons in ’94) GPPS (General Purpose PS)
• Clear and colorless with excellent optical properties and high stiffness.
• It is brittle until biaxially oriented when it becomes flexible and durable.
– Graft copolymer or blend with elastomers- High Impact Polystyrene (HIPS):
• Tough, white or clear in color, and easily extruded or molded.
• Properties are dependent upon the elastomer %, but are grouped into
– medium impact (Izod<1.5 ft-lb), high impact (Izod between 1.5 to 2.4 ft-lb) and super-high impact (Izod between 2.6 and 5 ft-lb)
– Copolymers include SAN (poly styrene-acrylonitrile), SMA (maleic anhydride), SBS (butadiene), styrene and acrylic copolymers.
– Expandable PS (EPS) is very popular for cups and insulation foam.
• EPS is made with blowing agents, such as pentane and isopentane.
• The properties are dependent upon cell size and cell size distribution
45
Polystyrene Polymers
• Poly-para-methyl-styrene (PPMS)– Similar to PS (Tg=100C) with a slightly higher Tg=110C
– Low cost alternative to PS in homo and co-polymers
• Poly-alpha-methyl-styrene (PAMS)
– High Tg =160C and better Temp resistance
– Not much commercial importance by itself
– Has significant use in copolymers
• Rubber-toughened impact polystyrene (HIPS)– Random copolymerization with small fraction of elastomer type repeat units.
Lowers Tg
– Block copolymerization of elastomeric component is more expensive, but keeps
Tg same as PS
C C
H
H H
nCH3
C C
H
H
n
CH3
46
PSB, SAN, ABS Chemical Structure
• PSB (copolymer -addition) * Styrene- acrylonitrile (SAN)
• ABS acrylonitrile butadiene styrene (Terpolymer- addition)
C C
H
H H
km
C C
H C:::N
H H
n
C C
CH3 CH3
H H
C C
H
H H
k m
C C
CH3CH3
H H
C C
H
H H
k
C C
H C:::N
H H
n
47
Polystyrene Co-Polymers
• Styrene-Butadiene (PSB) – Tg= % of each PS (100C) and Butadiene (-80C)
• Example, 50% PS and 50% B, Tg=10C
– Easy to copolymerize and can be rubbery (butadiene-dominant) or plastic like
(styrene-like), out 70% of the PSB is styrene dominant
– Random (styrene dominant) copolymers have been used in emulsion (latex)
form to produce coatings (paints).
– Block copolymers are commercial butadiene styrene-plastics
• Styrene Acrylonitrile (SAN)
– Random copolymer of 30% polyacrylonitrile repeat units yields
• Increased Temp performance and transparent, ease to process
• Resistant to food and body oils
– Used for transparent medical products, houseware care items
– Polyalloys (blends) with polysulphone
48
Polystyrene Co-Polymers• Acrylonitrile Butadiene Styrene (ABS)
– First introduced in the late 1940s as replacement for rubber.
– Terpolymer: Three repeat units vary according to grade (20%A, 20%B, 60%S)
• Acrylonitrile for chemical and temperature resistance
• Butadiene for impact resistance; Styrene for cost and processability
• Graft polymerization techniques are used to produce ABS
– Very versatile applications that are injection molded and extruded
• Rigid pipes and fittings, thermoformed refrigerator door liners, Legos toys
• Small boat hulls, telephone and computer housings
• Family of materials that vary from high gloss to low matte finish, and
from low to high impact resistance.
• Additives enable ABS grades that are flame retardant, transparent,
high heat-resistance, foamable, or UV-stabilized
• ABS-based polyalloys (blends)
– PVC/ABS for flame resistance
– TPU/ABS for polyurethane; PSU/ABS for polysulphone
– PC/ABS for temperature and impact resistance (Saturn door)
49
Mechanical Properties of PS, ABS, SANMechanical Properties
PS ABS SAN
Density, g/cc 1.04 1.16-1.21 1.07
Tensile Strength,
psi
5,000 - 7,200 3,300 - 8,000 10,000 -12,000
Tensile Modulus,
psi
330K-475K 320K-400K 475K-560K
Tensile
Elongation, %
1.2% - 2.5% 1.5%-25% 2%-3%
Impact Strengthft-lb/in
0.35-0.45 1.4-12 0.4-0.6
Hardness M60-75 R100-120 R83, M80
CLTE
10-6 mm/mm/C
50 -83 65- 95 65-68
HDT 264 psi 169F - 202F 190F - 225F 214F - 220F
C C
H
H H
n
Tg =100C
50
Physical Properties of PS, ABS, SAN
PS ABS SAN Optical
Transparent Transparent Transparent
Tmelt
100 C 125C 120C
Tg 70 -115C 110 -125C 120C
H20
Absorption
0.01-0.03% (24h)
0.2-0.6% (24h)
0.15-0.25% (24h)
Oxidation
Resistance
good good good
UV Resistance
fair fair fair
Solvent
Resistance
Soluble in Acetone, Benzene,
Toluene and Methylene dichloride
Soluble in Toluene and Ethylene dichloride, Partially in Benzene
Dissolved in ketones and esters
Alkaline
Resistance
Excellent Excellent Poor: attacked by oxidizing agents
Acid
Resistance
Poor: attacked by oxidizing agents
Poor: attacked by oxidizing agents
good
Cost $/lb
$0.41 $0.90 $0.87
51
Processing Properties of PS, ABS, SAN
PS ABS SAN
Tmelt 100 C 125C 120C
Recommended TempRange
(I:Injection, E:Extrusion)
I: 350F – 500FE: 350F- 500F
C: 300F - 400F
I: 380F – 500FC: 350F - 500F
I: 360F – 550FE: 360F -450F
C:300F - 400F
Molding Pressure 5 - 20 kpsi 8-25 kpsi 5-20 kpsi
Mold (linear) shrinkage(in/in)
0.004 – 0.007 0.004 – 0.008 0.003 – 0.005
52
Acrylic and Cellulosic Background • Acrylics (1901)
– Includes acrylic and methacrylic esters, acids, and derivatives.
– Used singularly or in combination with other polymers to produce
products ranging from soft, flexible elastomers to hard, stiff
thermoplastics and thermosets.
• Cellulosics (1883)
– Cellulose nitrate was first developed in the 1880s.
– First uses were billiard balls, combs, and photographic film.
– Cellulose acetate was developed in 1927 reduced the limitations of
flammability, and solvent requirement.
– In 1923, CA became the first material to be injection molded.
– Cellulose acetate butyrate (CAB) in1938 and Cellulose acetate
propionate (CAP) in 1945 found applications for hair brushes,
toothbrushes, combs, cosmetic cases, hand tool handles, steering
wheels, knobs, armrests, speakers, grilles, etc.
53
Acrylics Chemical Structure
• Acrylics- Basic formula - Polymethyl acrylate
• Polymethyl methacrylate -AcrylateStyreneAcrylonitrile (ASA)
C C
H COOR2
H R1
n
C C
H COOCH3
H H
n
C C
H COOCH3
H CH3
n
C C
H C:::N
H H
k
C C
H
H H
m
C C
H COOH
H H
n
54
Applications for PC and Acrylics
• PC (high impact strength, transparency, excellent creep and
temperature)
– lenses, films, windshields, light fixtures, containers, appliance
components and tool housings
– hot dish handles, coffee pots, popcorn popper lids, hair dryers.
– Pump impellers, safety helmets, beverage dispensers, trays, signs
– aircraft parts, films, cameras, packaging
• Acrylics
– Optical applications, outdoor advertising signs, aircraft windshields,
cockpit covers, bubble bodies for helicopters
– Plexiglass, window frames, (glass filled): tubs, counters, vanities
55
Mechanical Properties of Acrylic, PC,
PC/ABSMechanical Properties
Acrylic PC ABS PC/ABS
Density, g/cc 1.16- 1.19 1.2 1.16-1.21 1.07 - 1.15
Tensile Strength,psi
5,000 - 9,000 9,500 3,300 - 8,000 5,800 - 9,300
Tensile Modulus,
psi
200K – 500K 350 K 320K-400K 350K -450K
Tensile
Elongation, %
20 - 70% 110% 1.5%-25% 50%-60%
Impact Strengthft-lb/in
0.65 -2.5 16 1.4-12 6.4 - 11
Hardness M38-M68 M70 R100-120 R95 -R120
CLTE
10-6 mm/mm/C
48 - 80 68 65- 95 67
HDT 264 psi 165-209F 270 190F - 225F 225F
56
Physical Properties of Acrylic, PC, PC/ABS
Acrylic PC ABS PC/ABSOptical Transparent Transparent Transparent Transparent
Tmelt 105C 150C 125C 135C
Tg 75 -105C 110 -125C 110 -125C 120C
H20
Absorption
0.01-0.03% (24h) 0.2-0.6% (24h) 0.2-0.6% (24h) 0.15-0.25% (24h)
Oxidation
Resistance
good good good good
UV Resistance fair fair fair fair
Solvent
Resistance
Soluble in
Acetone, Benzene,Toluene, ethylene
dichloride
Partially Soluble in
Acetone, Benzene,Toluene. Dissolves inhot benzene-toluene
Soluble in Toluene
and Ethylenedichloride, Partially in
Benzene
Soluble in Toluene
and Ethylenedichloride, Partially in
BenzeneAlkaline
Resistance
Excellent Excellent Excellent Poor: attacked byoxidizing agents
Acid
Resistance
Poor: attacked byoxidizing agents
Poor: attacked byoxidizing agents
Poor: attacked byoxidizing agents
good
Cost $/lb $0.41 $0.90 $0.90 $0.87
57
Advantages
• PC
– High impact strength, excellent creep resistance, transparent
– Very good dimensional stability and continuous temp over 120 C
• Acrylics
– Optical clarity, weatherability, electrical properties, rigid, high
gloss
Disadvantages• PC
– High processing temp,UV degradation
– Poor resistance to alkalines and subject to solvent cracking
• Acrylics
– Poor solvent resistance, stress cracking, combustibility, Use T 93C
58
Polyamide History • PA is considered the first engineering thermoplastic
• PA is one of many heterochain thermoplastics, which has
atoms other than C in the chain.
• PA invented in 1928 by Wallace Carothers, DuPont, in
search of a “super polyester” fiber with molecular weights
greater than 10,000. First commercial nylon in 1938.
• PA was created when a condensation reaction occurred
between amino acids, dibasic acids, and diamines.
• Nylons are described by a numbering system which
indicates the number of carbon atoms in the monomer
chains
– Amino acid polymers are designated by a single number, as nylon
6
– Diamines and dibasic acids are designated with 2 numbers, the first
59
Chemistry & Chemical Structurelinear polyamides• Thermoplastic nylons have amide (CONH) repeating link
• Nylon 6,6 - poly-hexamethylene-diamine (linear)
NH2(CH2)6NH2 + COOH(CH2)4COOH
hexamethylene diamine + Adipic Acid
n[NH2(CH2)6NH . CO (CH2)4COOH ] + (heat)
nylon salt
[NH2(CH2)6NH . CO (CH2)4CO ]n + nH2O
Nylon 6,6 polymer chain
• Nylon 6 - polycaprolactam (linear)
[NH(CH2)5CO ]n
60
Chemistry & Chemical Structurelinear polyamides
• Nylon 6, 10 - polyhexamethylenesebacamide (linear)
[NH2(CH2)6NH . CO (CH2)8CO]n
• Nylon 11 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)10CO ]n
• Nylon 12 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)11CO ]n
• Other Nylons
– Nylon 8, 9, 46, and copolymers from other diamines and acids
61
Chemistry & Chemical StructureAromatic polyamides (aramids)
• PMPI - poly m-phenylene isophthalamide (LCP fiber)
[ -NHCO - NHCO ]n
• PPPT - poly p-phenylene terephthalamide (LCP fiber)
[ -NHCO - NHCO ]n
• Nomax PMPI -
– first commercial aramid fiber for electrical insulation. LCP
fibers feature straight chain crystals
• Kevlar 29 PPPT-
– textile fiber for tire cord, ropes, cables etc.
• Kevlar 49 PPPT - reinforcing fiber for thermosetting resins
62
Chemistry & Chemical StructureTransparent polyamides
• PA- (6,3,T)
[CH2C3H6C2H4-NHCO - NHCO ]n
• PA - (6,T)
[(CH2) 6NHCO - NHCO ]n
• Transparent polyamides are commercially available
• Reduced crystallization due to introduction of side
groups
63
Applications for Polyamides
• Fiber applications
– 50% into tire cords (nylon 6 and nylon 6,6)
– rope, thread, cord,belts, and filter cloths.
– Monofilaments- brushes, sports equipment, and bristles (nylon 6,10)
• Plastics applications
– bearings, gears, cams
– rollers, slides, door latches, thread guides
– clothing, light tents, shower curtains, umbrellas
– electrical wire jackets (nylon 11)
• Adhesive applications
– hot melt or solution type
– thermoset reacting with epoxy or phenolic resins
– flexible adhesives for bread wrappers, dried soup packets,
64
Mechanical Properties of Polyamides
Mechanical Properties of NylonNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12
Density, g/cc 1.13-1.15 1.13-1.15 1.09 1.06-1.10
Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%
Molecular Weight 10,000–30,000 10,000–30,000 10,000–30,000 10,000–30,000
Tensile Strength,
psi
6,000 – 24,000 14,000 8,500 – 8,600 6,500 – 8,800
Tensile Modulus,
psi
300K 230K – 550K 250 K 220 - 290 K
Tensile
Elongation, %
30% - 100% 15%-80% 70% 150%
Impact Strength
ft-lb/in
0.6 – 2.2 0.55 – 1.0 1.2 1.0 –1.9
Hardness R80 - 102 R120 R111 M78
65
Physical Properties of PolyamideNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12
Optical Translucent toopaque
Translucent toopaque
Translucent to opaque Translucent to opaque
Tmelt 210C -220 C 255C – 265C 220 C 195 -219 C
Tg
H20
Absorption
1.3-1.9% (24h)8.5-10 (Max)
1.0-2.8% (24h)8.5% (Max)
1.4% (24h)3.3% (Max)
0.4 – 1.0% (24h)2.5 –3 % (Max)
Oxidation
Resistance
good good good good
UV Resistance Poor Poor Poor Poor
Solvent
Resistance
Dissolved by
phenol &formic acid
Dissolved by
phenol & formicacid
Dissolved by phenol &
formic acid
Dissolved by phenol &
formic acid
Alkaline
Resistance
Resistant Resistant Resistant Resistant
Acid
Resistance
Poor Poor Poor Poor
Cost $/lb $1.30 $1.30 $3.00 $3.10
66
Advantages Disadvantages of Polyamide• Advantages
– Tough, strong, impact resistant
– Low coefficient of friction
– Abrasion resistance
– High temperature resistance
– Processable by thermopalstic methods
– Good solvent resistance
– Resistant to bases
• Disadvantages
– High moisture absorption with dimensional instability
• loss of up to 30 % of tensile strength and 50% of tensile modulus
– Subject to attack by strong acids and oxidizing agents
– Requires UV stabilization
– High shrinkage in molded sections
– Electrical and mechanical properties influenced by moisture content
– Dissolved by phenols
67
Additives and Reinforcements to PA
• Additives- antioxidants, UV stabilizers, colorants, lubricants
• Fillers
– Talc
– Calcium carbonate
• Reinforcements
– Glass fiber- short fiber (1/8” or long fiber 1/4”)
– Mineral fiber (wolastonite)
– carbon fibers
– graphite fibers
– metallic flakes
– steel fibers
68
Properties of Reinforced Nylon
Nylon 6,6 Nylon 6,6 with30% short glass
Nylon 6,6 with30% long glass
Nylon 6,6 with30% carbon fiber
Density, g/cc 1.13-1.15 1.4 1.4 1.06-1.10
Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%
Molecular Weight 10,000–30,000 30,000 10,000–30,000 10,000–30,000
Tensile Strength,
psi
14,000 28,000 28,000 32,000
Tensile Modulus,
psi
230K – 550K 1,300K 1,400 K 3,300 K
Tensile
Elongation, %
15%-80% 3% 3% 4%
Impact Strengthft-lb/in
0.55 – 1.0 1.6-4.5 4.0 1.5
Hardness R120 R120 E60 R120
Moisture % 1.0-2.8% (24h)8.5% (Max)
0.7-1.1 (24h)5.5-6.5 (Max)
0.9 (24h)5.5-6.5 (Max)
0.7 (24h)5 (Max)
Cost $/lb $1.40 $1.70 $2.00 $2.70
69
Other Heterochain Polymers
• Polyimide
– Developed by Du Pont in 1962
– Obtained from a condensation polymerization of aromatic diamine
and an aromatic dianhydride
– Characterized as Linear thermoplastics that are difficult to process
– Many polyimides do not melt but are fabricated by machining
– Molding can occur if enough time for flow is allowed for T>Tg
• Advantages
– High temperature service (up to 700C)
– Excellent barrier, electrical properties, solvent and wear resistance
– Good adhesion and ezpecially suited for composite fabrication
ON
C
O
N
C
O
C C
70
Other Heterochain Polymers• Polyimide Disadvantages
– Difficulty to fabricate and requires venting of volatiles
– Hydroscopic and Subject to attacks by alkalines
– Comparatively high cost
• Applications
• Aerospace, electronics, and nuclear uses (versus flurocarbons)
• Office and industrial equipment; Laminates, dielectrics, and coatings
• Valve seats, gaskets, piston rings, thrust washers, and bushings
• Polyamide-imide
• Amorphous member of imide family, marketed in 1972 (Torlon), and
used in aerospace applications such as jet engine components
• Contains aromatic rings and nitrogen linkage
• Advantages include: High temperature properties (500F), low
coefficient of friction, and dimensional stability.
71
Other Heterochain Polymers
• Polyacetal or Polyoxymethylene (POM)
• Polymerized from formaldehyde gas
• First commercialized in 1960 by Du Pont
• Similar in properties to Nylon and used for plumbing fixtures, pump
impellers, conveyor belts, aerosol stem valves, VCR tape housings
• Advantages
• Easy to fabricate, has glossy molded surfaces, provide superior
fatigue endurance, creep resistance, stiffness, and water resistance.
• Among the strongest and stiffest thermoplastics.
• Resistant to most chemicals, stains, and organic solvents
• Disadvantages
• Poor resistance to acids and bases and difficult to bond
• Subject to UV degradation and is flammable
• Toxic fumes released upon degradation
H-O-(CH2-O-CH2-O)NH:R
72
Mechanical Properties
Nylon 6 Acetal Polyimid Polyamide-imideDensity, g/cc 1.13-1.15 1.42 1.43 1.41
Crystallinity 30-% - 50%
Molecular Weight 10,000–30,000
Tensile Strength,
psi
6,000 – 24,000 10,000 10,000 26,830
Tensile Modulus,
psi
300K 520K
Tensile
Elongation, %
30% - 100% 40% - 75%
Impact Strengthft-lb/in
0.6 – 2.2 0.07 0.9 2.5
Hardness R80 - 102 R120 E50 E78
Tmelt 210 - 220 C 175-181 C Tg=275CMoisture
24 hr
max
1.3 - 1.9%8.5 - 10%
0.25 to 0.40%1.41%
0.32% .28%
Optical Translucent toopaque
Translucent toopaque
opaque Transparent toopaque
73
Polyester History
• 1929 W. H. Carothers suggested classification of polymers
into two groups, condensation and addition polymers.
• Carothers was not successful in developing polyester fibers
from linear aliphatic polyesters due to low melting point and
high solubility. No commercial polymer is based on these.
• p-phenylene group is added for stiffening and leads to
polymers with high melting points and good fiber-forming
properties, e.g., PET.
• Polymers used for films and for fibers
• Polyesters is one of many heterochain thermoplastics, which
has atoms other than C in the chain.
• Polyesters includes unsaturated (thermosets), saturated and
aromatic thermoplastic polyesters.
74
Chemistry & Chemical Structurelinear polyesters (versus branched)
• Thermoplastic polyesters have ester(-C-O) repeating link
• Polyester (linear) PET and PBT
C6H4(COOH)2 + (CH2)2(OH)2 -[(CH2)2 -O- C - C-
O]-
terephthalic acid + ethylene glycol Polyethylene terephthalate (PET)
C6H4(COOH)2 + (CH2)4(OH)2 -[(CH2)4 -O- C - C-
O]-
terephthalic acid + butylene glycol Polybutylene terephthalate (PBT)
O
O O
O O
75
Chemistry & Chemical Structurelinear polyesters (versus branched)
• Wholly aromatic copolyesters (LCP)
– High melting sintered: Oxybenzoyl (does not melt below its
decomposition temperature. Must be compression molded)
– Injection moldable grades: Xydar and Vectra
– Xydar (Amoco Performance Products)
• terephthalic acid, p,p’- dihydroxybiphenyl, and p-hydroxybenzoic
acid
– Grade 1: HDT of 610F
– Grade 2: HDT of 480 F
– Vectra (Hoechst Celanese Corp.)
• para-hydroxybenzoic acid and hydroxynaphtholic acid
– Contains rigid chains of long, flat monomer units which are thought to
undergo parallel ordering in the melt and form tightly packed fibrous
chains in molded parts.
76
PET Chemical Structure and Applications• The flexible, but short, (CH2)2 groups tend to leave the
chains relatively stiff and PET is notes for its very slow
crystallization. If cooled rapidly from the melt to a Temp
below Tg, PET solidifies in amorphous form.
• If PET is reheated above Tg, crystallizaiton takes place to
up to 30%.
• In many applications PET is first pre-shaped in
amorphous state and then given a uniaxial (fibers or
tapes) or biaxial (film or containers) crystalline
orientation.
• During Injection Molding PET can yield amorphous
transparent objects (Cold mold) or crystalline opaques
objects (hot mold)
77
PBT Chemical Structure and Applications
• The longer, more flexible (CH2)4 groups allow for more
rapid crystallization than PET.
• PBT is not as conveniently oriented as PET and is
normally injection molded.
• PBT has a sharp melting transition with a rather low melt
viscosity.
• PBT has rapid crystallization and high degree of
crystallization causing warpage concerns
78
Thermoplastic Aromatic Copolyesters• Polyarylesters
– Repeat units feature only aromatic-type groups (phenyl or aryl
groups) between ester linkages.
– Called wholly aromatic polyesters
– Based on a combination of suitable chemicals
• p-hydroxybenzoic acid
• terephthalic acid
• isophthalic acid,
• bisphenol-A
– Properties correspond to a very stiff and regular chain with high
crystallinity and high temperature stability
– Applications include bearings, high temperature sensors, aerospace
applications
– Processed in injection molding and compression molding
– Most thermoplastic LCP appear to be aromatic copolyesters
79
Applications for Polyesters (PET)• Blow molded bottles
• 100% of 2-liter beverage containers and liquid products
• Fiber applications
• 25% of market in tire cords, rope, thread, cord, belts, filter cloths.
• Monofilaments- brushes, sports equipment, clothing, carpet, bristles
• Tape form- uniaxially oriented tape form for strapping
• Film and sheets
• photographic and x-ray films; biaxial sheet for food packages
• Molded applications- Reinforced PET [Rynite, Valox, Impet]
• luggage racks, grille-opening panels, functional housings such as
windshield wiper motors, blade supports, and end bells
• sensors, lamp sockets, relays, switches, ballasts, terminal blocks
• Appliances and furniture
• oven and appliance handles, coil forms for microwaves
• panel pedestal bases, seat pans, chair arms, and casters
80
Applications for Polyesters (PBT and LCP)
• PBT - 30 M lbs in 1988
• Molded applications (PBT) [Valox, Xenoy, Vandar, Pocan]
– distributers, door panels, fenders, bumper fascias
– automotive cables, connectors, terminal blocks, fuse holders and
motor parts, distributor caps, door and window hardware
• Extruded applications
– extrusion-coat wire
– extruded forms and sheet produced with some difficulty
• Electronic Devices (LCP) [26 M lbs] [Terylene, Dacron, Kodel]
– fuses, oxygen and transmission sensors
– chemical process equipment and sensors
– coil
81
Mechanical Properties of Polyesters
Mechanical Properties of polyesterPET PBT LCP Polyester
Density, g/cc 1.29-1.40 1.30 - 1.38 1.35 - 1.40
Crystallinity 10% - 30% 60% >80%
Molecular Weight
Tensile Strength,
psi
7,000 – 10,500 8,200 16,000 – 27,000
Tensile Modulus,
psi
400K - 600K 280K – 435K 1,400K - 2,800K
Tensile
Elongation, %
30% - 300% 50%-300% 1.3%-4.5%
Impact Strengthft-lb/in
0.25 - 0.70 0.7 - 1.0 2.4 - 10
CLTE
10-6 in/in/C
65 60-95 25-30
HDT 264 psi 70F -100F 122F - 185F 356F -671F
82
Physical Properties of Polyester
PET PBT LCP Polyester
Optical Transparent toOpaque
Opaque Opaque
Tmelt 245C -265 C 220C – 267C 400 C - 421 C
Tg 73C - 80C
H20
Absorption
0.1 - 0.2% (24h) 0.085% (24h)0.45% (Max)
<0.1% (24h)<0.1% (Max)
Oxidation
Resistance
good good good
UV Resistance Poor Poor none
Solvent
Resistance
Attacked byhalogen
hydrocarbons
good good
Alkaline
Resistance
Poor Poor Poor
Acid
Resistance
Poor Poor fair
Cost $/lb $0.53 $1.48 $7.00 - $10.00
83
Advantages and Disadvantages of
Polyesters• Advantages
– Tough and rigid and PBT has low moisture absorption
– Processed by thermoplastic operations
– Recycled into useful products as basis for resins in such
applications as sailboats, shower units, and floor tiles
– PET flakes from PET bottles are in great demand for fiberfill for
pillows and sleeping bags, carpet fiber, geo-textiles, and regrind
for injection and sheet molding
• Disadvantages
– Subject to attack by acids and bases
– Low thermal resistance
– Poor solvent resistance
– Must be adequately dried in dehumidifier prior to processing to
prevent hydrolytic degradation.
84
Thermoplastic Copolyesters• Copolyester is applied to those polyesters whose synthesis
uses more than one glycol and/or more than one dibasic
acid.
• Copolyester chain is less regular than monopolyester chain
and as a result has less crystallinity
• PCTA copolyester (Poly cyclo-hexane-dimethanol-
terephthalate acid) [amorphous]
– Reaction includes cyclohexanedimethanol and terephthalic acid
with another acid substituted for a portion of the terephthalic acid
– Extruded as transparent film or sheets that are suitable for
packaging applications (frozen meats shrink bags, blister packages,
etc..)
• Glycol-modified PET (PETG) [amorphous]
– Blow-molded containers, thermoformed blister packages.
85
ABS, PC Background • ABS was invented during WWII as a replacement for
rubber
– ABS is a terpolymer: acrylonitrile (chemical resistance), butadiene
(impact resistance), and styrene (rigidity and processing ease)
– Graft polymerization techniques are used to produce ABS
– Family of materials that vary from high gloss to low matte finish,
and from low to high impact resistance.
– Additives enable ABS grades that are flame retardant, transparent,
high heat-resistance, foamable, or UV-stabilized.
• PC was invented in 1898 by F. Bayer in Germany
– Commercial production began in the US in 1959.
– Amorphous, engineering thermoplastic that is known for
toughness, clarity, and high-heat deflection temperatures.
– Polycarbonates are linear, amorphous polyesters because they
contain esters of carbonic acid and an aromatic bisphenol.
86
Polyamide History • PA is considered the first engineering thermoplastic
• PA is one of many heterochain thermoplastics, which has
atoms other than C in the chain.
• PA invented in 1928 by Wallace Carothers, DuPont, in
search of a “super polyester” fiber with molecular weights
greater than 10,000. First commercial nylon in 1938.
• PA was created when a condensation reaction occurred
between amino acids, dibasic acids, and diamines.
• Nylons are described by a numbering system which
indicates the number of carbon atoms in the monomer
chains
– Amino acid polymers are designated by a single number, as nylon
6
– Diamines and dibasic acids are designated with 2 numbers, the first
87
Chemistry & Chemical Structurelinear polyamides• Thermoplastic nylons have amide (CONH) repeating link
• Nylon 6,6 - poly-hexamethylene-diamine (linear)
NH2(CH2)6NH2 + COOH(CH2)4COOH
hexamethylene diamine + Adipic Acid
n[NH2(CH2)6NH . CO (CH2)4COOH ] + (heat)
nylon salt
[NH2(CH2)6NH . CO (CH2)4CO ]n + nH2O
Nylon 6,6 polymer chain
• Nylon 6 - polycaprolactam (linear)
[NH(CH2)5CO ]n
88
Chemistry & Chemical Structurelinear polyamides
• Nylon 6, 10 - polyhexamethylenesebacamide (linear)
[NH2(CH2)6NH . CO (CH2)8CO]n
• Nylon 11 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)10CO ]n
• Nylon 12 - Poly(11-amino-undecanoic-amide (linear)
[NH(CH2)11CO ]n
• Other Nylons
– Nylon 8, 9, 46, and copolymers from other diamines and acids
89
Chemistry & Chemical StructureAromatic polyamides (aramids)
• PMPI - poly m-phenylene isophthalamide (LCP fiber)
[ -NHCO - NHCO ]n
• PPPT - poly p-phenylene terephthalamide (LCP fiber)
[ -NHCO - NHCO ]n
• Nomax PMPI - first commercial aramid fiber for
electrical insulation. LCP fibers feature straight chain
crystals
• Kevlar 29 PPPT- textile fiber for tire cord, ropes, cables
etc.
90
Chemistry & Chemical StructureTransparent polyamides
• PA- (6,3,T)
[CH2C3H6C2H4-NHCO - NHCO ]n
• PA - (6,T)
[(CH2) 6NHCO - NHCO ]n
• Transparent polyamides are commercially available
• Reduced crystallization due to introduction of side
groups
91
Applications for Polyamides
• Fiber applications
– 50% into tire cords (nylon 6 and nylon 6,6)
– rope, thread, cord,belts, and filter cloths.
– Monofilaments- brushes, sports equipment, and bristles (nylon 6,10)
• Plastics applications
– bearings, gears, cams
– rollers, slides, door latches, thread guides
– clothing, light tents, shower curtains, umbrellas
– electrical wire jackets (nylon 11)
• Adhesive applications
– hot melt or solution type
– thermoset reacting with epoxy or phenolic resins
– flexible adhesives for bread wrappers, dried soup packets,
92
Mechanical Properties of Polyamides
Mechanical Properties of NylonNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12
Density, g/cc 1.13-1.15 1.13-1.15 1.09 1.06-1.10
Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%
Molecular Weight 10,000–30,000 10,000–30,000 10,000–30,000 10,000–30,000
Tensile Strength,
psi
6,000 – 24,000 14,000 8,500 – 8,600 6,500 – 8,800
Tensile Modulus,
psi
300K 230K – 550K 250 K 220 - 290 K
Tensile
Elongation, %
30% - 100% 15%-80% 70% 150%
Impact Strength
ft-lb/in
0.6 – 2.2 0.55 – 1.0 1.2 1.0 –1.9
Hardness R80 - 102 R120 R111 M78
93
Physical Properties of PolyamideNylon 6 Nylon 6,6 Nylon 6,10 Nylon 6,12
Optical Translucent toopaque
Translucent toopaque
Translucent to opaque Translucent to opaque
Tmelt 210C -220 C 255C – 265C 220 C 195 -219 C
Tg
H20
Absorption
1.3-1.9% (24h)8.5-10 (Max)
1.0-2.8% (24h)8.5% (Max)
1.4% (24h)3.3% (Max)
0.4 – 1.0% (24h)2.5 –3 % (Max)
Oxidation
Resistance
good good good good
UV Resistance Poor Poor Poor Poor
Solvent
Resistance
Dissolved by
phenol &formic acid
Dissolved by
phenol & formicacid
Dissolved by phenol &
formic acid
Dissolved by phenol &
formic acid
Alkaline
Resistance
Resistant Resistant Resistant Resistant
Acid
Resistance
Poor Poor Poor Poor
Cost $/lb $1.30 $1.30 $3.00 $3.10
94
Advantages Disadvantages of Polyamide
• Advantages– Tough, strong, impact resistant
– Low coefficient of friction
– Abrasion resistance
– High temperature resistance
– Processable by thermopalstic methods
– Good solvent resistance
– Resistant to bases
• Disadvantages
– High moisture absorption with dimensional instability
• loss of up to 30 % of tensile strength and 50% of tensile modulus
– Subject to attack by strong acids and oxidizing agents
– Requires UV stabilization
– High shrinkage in molded sections
– Electrical and mechanical properties influenced by moisture content
95
Additives and Reinforcements to PA
• Additives- antioxidants, UV stabilizers, colorants, lubricants
• Fillers
– Talc
– Calcium carbonate
• Reinforcements
– Glass fiber- short fiber (1/8” or long fiber 1/4”)
– Mineral fiber (wolastonite)
– carbon fibers
– graphite fibers
– metallic flakes
– steel fibers
96
Properties of Reinforced Nylon
Nylon 6,6 Nylon 6,6 with30% short glass
Nylon 6,6 with30% long glass
Nylon 6,6 with30% carbon fiber
Density, g/cc 1.13-1.15 1.4 1.4 1.06-1.10
Crystallinity 30-% - 50% 30-% - 50% 30-% - 50% 30-% - 50%
Molecular Weight 10,000–30,000 30,000 10,000–30,000 10,000–30,000
Tensile Strength,
psi
14,000 28,000 28,000 32,000
Tensile Modulus,
psi
230K – 550K 1,300K 1,400 K 3,300 K
Tensile
Elongation, %
15%-80% 3% 3% 4%
Impact Strengthft-lb/in
0.55 – 1.0 1.6-4.5 4.0 1.5
Hardness R120 R120 E60 R120
Moisture % 1.0-2.8% (24h)8.5% (Max)
0.7-1.1 (24h)5.5-6.5 (Max)
0.9 (24h)5.5-6.5 (Max)
0.7 (24h)5 (Max)
Cost $/lb $1.40 $1.70 $2.00 $2.70
97
Other Heterochain Polymers
• Polyimide
– Developed by Du Pont in 1962
– Obtained from a condensation polymerization of aromatic diamine
and an aromatic dianhydride
– Characterized as Linear thermoplastics that are difficult to process
– Many polyimides do not melt but are fabricated by machining
– Molding can occur if enough time for flow is allowed for T>Tg
• Advantages
– High temperature service (up to 700C)
– Excellent barrier, electrical properties, solvent and wear resistance
– Good adhesion and ezpecially suited for composite fabrication
ON
C
O
N
C
O
C C
98
Other Heterochain Polymers• Polyimide Disadvantages
– Difficulty to fabricate and requires venting of volatiles
– Hydroscopic
– Subject to attacks by alkalines
– Comparatively high cost
• Applications
– Aerospace, electronics, and nuclear uses (competes with
flurocarbons)
– Office and industrial equipment; Laminates, dielectrics, and
coatings
– Valve seats, gaskets, piston rings, thrust washers, and bushings
• Polyamide-imide
– Amorphous member of imide family, marketed in 1972 (Torlon),
and used in aerospace applications such as jet engine components
– Contains aromatic rings and nitrogen linkage
99
Other Heterochain Polymers
• Polyacetal or Polyoxymethylene (POM)
– Polymerized from formaldehyde gas
– First commercialized in 1960 by Du Pont
– Similar in properties to Nylon and used for plumbing fixtures,
pump impellers, conveyor belts, aerosol stem valves, VCR tape
housings
• Advantages
– Easy to fabricate, has glossy molded surfaces, provide superior
fatigue endurance, creep resistance, stiffness, and water resistance.
– Among the strongest and stiffest thermoplastics.
– Resistant to most chemicals, stains, and organic solvents
• Disadvantages
– Poor resistance to acids and bases and difficult to bond
– Subject to UV degradation and is flammable
H-O-(CH2-O-CH2-O)NH:R
100
Mechanical Properties
Nylon 6 Acetal Polyimid Polyamide-imideDensity, g/cc 1.13-1.15 1.42 1.43 1.41
Crystallinity 30-% - 50%
Molecular Weight 10,000–30,000
Tensile Strength,
psi
6,000 – 24,000 10,000 10,000 26,830
Tensile Modulus,
psi
300K 520K
Tensile
Elongation, %
30% - 100% 40% - 75%
Impact Strengthft-lb/in
0.6 – 2.2 0.07 0.9 2.5
Hardness R80 - 102 R120 E50 E78
Tmelt 210 - 220 C 175-181 C Tg=275CMoisture
24 hr
max
1.3 - 1.9%8.5 - 10%
0.25 to 0.40%1.41%
0.32% .28%
Optical Translucent toopaque
Translucent toopaque
opaque Transparent toopaque
101
Polyester History
• 1929 W. H. Carothers suggested classification of polymers
into two groups, condensation and addition polymers.
• Carothers was not successful in developing polyester fibers
from linear aliphatic polyesters due to low melting point and
high solubility. No commercial polymer is based on these.
• p-phenylene group is added for stiffening and leads to
polymers with high melting points and good fiber-forming
properties, e.g., PET.
• Polymers used for films and for fibers
• Polyesters is one of many heterochain thermoplastics, which
has atoms other than C in the chain.
• Polyesters includes unsaturated (thermosets), saturated and
aromatic thermoplastic polyesters.
102
Chemistry & Chemical Structurelinear polyesters (versus branched)
• Thermoplastic polyesters have ester(-C-O) repeating link
• Polyester (linear) PET and PBT
C6H4(COOH)2 + (CH2)2(OH)2 -[(CH2)2 -O- C - C-
O]-
terephthalic acid + ethylene glycol Polyethylene terephthalate (PET)
C6H4(COOH)2 + (CH2)4(OH)2 -[(CH2)4 -O- C - C-
O]-
terephthalic acid + butylene glycol Polybutylene terephthalate (PBT)
O
O O
O O
103
Chemistry & Chemical Structurelinear polyesters (versus branched)
• Wholly aromatic copolyesters (LCP)
– High melting sintered: Oxybenzoyl (does not melt below its
decomposition temperature. Must be compression molded)
– Injection moldable grades: Xydar and Vectra
– Xydar (Amoco Performance Products)
• terephthalic acid, p,p’- dihydroxybiphenyl, and p-hydroxybenzoic
acid
– Grade 1: HDT of 610F
– Grade 2: HDT of 480 F
– Vectra (Hoechst Celanese Corp.)
• para-hydroxybenzoic acid and hydroxynaphtholic acid
– Contains rigid chains of long, flat monomer units which are thought to
undergo parallel ordering in the melt and form tightly packed fibrous
chains in molded parts.
104
PET Chemical Structure and Applications
• The flexible, but short, (CH2)2 groups tend to leave the
chains relatively stiff and PET is notes for its very slow
crystallization. If cooled rapidly from the melt to a Temp
below Tg, PET solidifies in amorphous form.
• If PET is reheated above Tg, crystallizaiton takes place to
up to 30%.
• In many applications PET is first pre-shaped in
amorphous state and then given a uniaxial (fibers or
tapes) or biaxial (film or containers) crystalline
orientation.
• During Injection Molding PET can yield amorphous
transparent objects (Cold mold) or crystalline opaques
objects (hot mold)
105
PBT Chemical Structure and Applications
• The longer, more flexible (CH2)4 groups allow for more
rapid crystallization than PET.
• PBT is not as conveniently oriented as PET and is
normally injection molded.
• PBT has a sharp melting transition with a rather low melt
viscosity.
• PBT has rapid crystallization and high degree of
crystallization causing warpage concerns
106
Thermoplastic Aromatic Copolyesters• Polyarylesters
– Repeat units feature only aromatic-type groups (phenyl or aryl
groups) between ester linkages.
– Called wholly aromatic polyesters
– Based on a combination of suitable chemicals
• p-hydroxybenzoic acid
• terephthalic acid
• isophthalic acid,
• bisphenol-A
– Properties correspond to a very stiff and regular chain with high
crystallinity and high temperature stability
– Applications include bearings, high temperature sensors, aerospace
applications
– Processed in injection molding and compression molding
– Most thermoplastic LCP appear to be aromatic copolyesters
107
Applications for Polyesters (PET)• Blow molded bottles
– 100% of 2-liter beverage containers and liquid products
• Fiber applications
– 25% of market in tire cords, rope, thread, cord, belts, and filter
cloths.
– Monofilaments- brushes, sports equipment, clothing, carpet,
bristles
– Tape form- uniaxially oriented tape form for strapping
• Film and sheets
– photographic and x-ray films; biaxial sheet for food packages
• Molded applications- Reinforced PET [Rynite, Valox, Impet]
– luggage racks, grille-opening panels, functional housings such as
windshield wiper motors, blade supports, and end bells
– sensors, lamp sockets, relays, switches, ballasts, terminal blocks
• Appliances and furniture
108
Applications for Polyesters (PBT and LCP)
• PBT - 30 M lbs in 1988
• Molded applications (PBT) [Valox, Xenoy, Vandar, Pocan]
– distributers, door panels, fenders, bumper fascias
– automotive cables, connectors, terminal blocks, fuse holders and
motor parts, distributor caps, door and window hardware
• Extruded applications
– extrusion-coat wire
– extruded forms and sheet produced with some difficulty
• Electronic Devices (LCP) [26 M lbs] [Terylene, Dacron, Kodel]
– fuses, oxygen and transmission sensors
– chemical process equipment and sensors
– coil
109
Mechanical Properties of Polyesters
Mechanical Properties of polyesterPET PBT LCP Polyester
Density, g/cc 1.29-1.40 1.30 - 1.38 1.35 - 1.40
Crystallinity 10% - 30% 60% >80%
Molecular Weight
Tensile Strength,
psi
7,000 – 10,500 8,200 16,000 – 27,000
Tensile Modulus,
psi
400K - 600K 280K – 435K 1,400K - 2,800K
Tensile
Elongation, %
30% - 300% 50%-300% 1.3%-4.5%
Impact Strengthft-lb/in
0.25 - 0.70 0.7 - 1.0 2.4 - 10
CLTE
10-6 in/in/C
65 60-95 25-30
HDT 264 psi 70F -100F 122F - 185F 356F -671F
110
Physical Properties of Polyester
PET PBT LCP Polyester
Optical Transparent toOpaque
Opaque Opaque
Tmelt 245C -265 C 220C – 267C 400 C - 421 C
Tg 73C - 80C
H20
Absorption
0.1 - 0.2% (24h) 0.085% (24h)0.45% (Max)
<0.1% (24h)<0.1% (Max)
Oxidation
Resistance
good good good
UV Resistance Poor Poor none
Solvent
Resistance
Attacked byhalogen
hydrocarbons
good good
Alkaline
Resistance
Poor Poor Poor
Acid
Resistance
Poor Poor fair
Cost $/lb $0.53 $1.48 $7.00 - $10.00
111
Advantages/Disadvantages of Polyesters• Advantages
– Tough and rigid
– Processed by thermoplastic operations
– Recycled into useful products as basis for resins in such
applications as sailboats, shower units, and floor tiles
– PET flakes from PET bottles are in great demand for fiberfill for
pillows and sleeping bags, carpet fiber, geo-textiles, and regrind
for injection and sheet molding
– PBT has low moisture absorption
• Disadvantages
– Subject to attack by acids and bases
– Low thermal resistance
– Poor solvent resistance
– Must be adequately dried in dehumidifier prior to processing to
prevent hydrolytic degradation.
112
Thermoplastic Copolyesters• Copolyester is applied to those polyesters whose synthesis
uses more than one glycol and/or more than one dibasic
acid.
• Copolyester chain is less regular than monopolyester chain
and as a result has less crystallinity
• PCTA copolyester (Poly cyclo-hexane-dimethanol-
terephthalate acid) [amorphous]
– Reaction includes cyclohexanedimethanol and terephthalic acid
with another acid substituted for a portion of the terephthalic acid
– Extruded as transparent film or sheets that are suitable for
packaging applications (frozen meats shrink bags, blister packages,
etc..)
• Glycol-modified PET (PETG) [amorphous]
– Blow-molded containers, thermoformed blister packages.
113
ABS Background
• ABS was invented during WWII as a replacement for
rubber
– ABS is a terpolymer: acrylonitrile (chemical resistance), butadiene
(impact resistance), and styrene (rigidity and processing ease)
– Graft polymerization techniques are used to produce ABS
– Family of materials that vary from high gloss to low matte finish,
and from low to high impact resistance.
– Additives enable ABS grades that are flame retardant, transparent,
high heat-resistance, foamable, or UV-stabilized.
114
PEEK History
• Polyether-ether-ketone (PEEK) and Polyether ketone (PEK)
– PEEK invented by ICI in 1982. PEK introduced in 1987
• PEEK and PEK are aromatic polyketones
– Volume for polyketones is 500,000 lbs per year in 1990. Estimated
to reach 3 to 4 million by 2000.
– Cost is $30 per pound (as of October 1998)
• Product Names– ICI: Vivtrex
– BASF: Ultrapak
– Hoechst Celanese: Hostatec
– DuPont: PEKK
– Amoco: Kadel
115
Chemistry & Chemical Structure
• PEEK- Poly-ether-ether-ketone
O O C
• PEK- Poly-ether-ketone
O C
O
n
O
n
116
Chemical Synthesis
• Synthesis of polyketones
– PEK: Formation of the carbonyl link by polyaroylation from low
cost starting materials. Requires solvents such as liquid HF.
Excessive solvents and catalyst cause the high material cost.
– PEEK: Formation of ether link using phenoxide anions to displace
activated halogen.
O
C ClOHF, catalyst
O
n
O C + HCl + CO2 +H20
PEK
K2CO3, DPS
O
C FF OHOH+ PEEK + CO2 +H20 +KF
117
PEEK and PEK Applications• Aerospace: replacement of Al
– Fuel line brakes to replacement of primary structure
• Electrical– wire coating for nuclear applications, oil wells, flammability-critical mass
transit.
– Semi-conductor wafer carriers which can show better rigidity, minimum
weight, and chemical resistance to fluoropolymers.
• Other applications– Chemical and hydrolysis resistant valves (replaced glass)
– Internal combustion engines (replaced thermosets)
– Cooker components (replaced enamel)
– Automotive components (replaced metal)
– High temperature and chemical resistant filters from fiber
– Low friction bearings
118
Mechanical Properties of PEEK
Mechanical PropertiesPEEK LCP Polyester Nylon 6,6
Density, g/cc 1.30-1.32 1.35 - 1.40 1.13-1.15
Tensile Strength,
psi10,000 – 15,000 16,000 – 27,000 14,000
Tensile Modulus,
psi
500K 1,400K - 2,800K 230K – 550K
Tensile
Elongation, %
30% - 150% 1.3%-4.5% 15%-80%
Impact Strengthft-lb/in
0.6 – 2.2 2.4 - 10 0.55 – 1.0
Hardness R120 R124 R120
CLTE
10-6 mm/mm/C
40 - 47 25-30 80
HDT 264 psi 320 F 356F -671F 180F
119
Physical Properties of PEEKPhysical Properties
PEEK LCP Polyester Nylon 6,6
Optical Opaque Opaque Translucent to opaque
Tmelt 334 C 400 C 255C – 265C
Tg 177 C
H20
Absorption
0.1-0.14% (24h)0.5% (Max)
0.1% (24h)0.1% (Max)
1.0-2.8% (24h)8.5% (Max)
Oxidation
Resistancegood Good good
UV Resistance Poor good Poor
Solvent
Resistance
good good Dissolved by phenol &formic acid
Alkaline
Resistance
good Poor Resistant
Acid
Resistance
good fair Poor
Cost $/lb $30 $7 - $10 $1.30
120
Properties of Reinforced PEEK
Mechanical Properties ReinforcedPEEK PEEK 30%
glass fibers
PEEK with 30%
carbon fibers
Density, g/cc 1.30-1.32 1.52 1.43
Tensile Strength,psi
10,000 – 15,000 23,000 – 29,000 31,000
Tensile Modulus,psi
500K 1,300K – 1,600K 1,900K – 3,500K
Tensile
Elongation, %
30% - 150% 2%-3% 1% - 4%
Impact Strengthft-lb/in
1.6 2.1 – 2.7 1.5 – 2.1
Hardness R120 R120
CLTE10-6 mm/mm/C
40 - 47 12-22 15-22
HDT 264 psi 320 F 550F -600F 550F -610F
121
Processing Properties of PEEK
Processing Properties
PEEK LCP Polyester Nylon 6,6
Tmelt 334 C 400 C - 420 C 255C – 265C
Recommended TempRange
(I:Injection, E:Extrusion)
I: 660F – 750FE: 660F – 725F
I: 540F – 770F I: 500F – 620F
Molding Pressure 10 -20 kpsi 5 - 16 kpsi 1 -20 kpsi
Mold (linear) shrinkage(in/in)
0.011 0.001 – 0.008 0.007 – 0.018
122
Advantages and Disadvantages of Polyketones
• Advantages
– Very high continuous use temperature (480F)
– Outstanding chemical resistance
– Outstanding wear resistance
– Excellent hydrolysis resistance
– Excellent mechanical properties
– Very low flammability and smoke generation
– Resistant to high levels of gamma radiation
• Disadvantages
– High material cost
– High processing temperatures
123
Polyphenylene Materials
•Several plastics have been developed with the benzene ring in
the backbone »Polyphenylene
»Polyphenylene oxide
(amorphous)
»Poly(phenylene sulfide)
(crystalline)
»Polymonochloroparaxylene
O OO
S S S
CH2 CH2
Cl Cl
124
PPO and PPS Materials
*Advantages of PPS *Advantages of PPO
- Usage Temp at 450F - Good fatigue and impact
strength
- Good radiation resistance - Good radiation resistance
- Excellent dimensional stability - Excellent dimensional stability
- Low moisture absorption - Low oxidation
- Good solvent and chemical resistance
- Excellent abrasion resistance
*Disadvantages of PPS *Disadvantages of PPO
- High Cost - High cost
- High process temperatures -Poor resistance to certain
chemicals
- Poor resistance to chlorinated hydrocarbons
125
PPO and PPS Applications
*PPS Applications *PPO Applications
- Computer components - Video display terminals
- Range components - Pump impellers
- Hair dryers - Small appliance housings
- Submersible pump enclosures - Instrument panels
- Small appliance housings - Automotive parts
126
PPS and PPO Mechanical PropertiesMechanical Properties
PPS PPO Nylon 6,6
Density, g/cc 1.30 1.04 – 1.10 1.13-1.15
Tensile Strength,
psi
9,500 7,800 14,000
Tensile Modulus,
psi
480K 360K 230K – 550K
Tensile
Elongation, %
1% - 2% 60% - 400% 15%-80%
Impact Strengthft-lb/in
< 0.5 4 - 6 0.55 – 1.0
Hardness R123 R115 R120
CLTE
10-6 mm/mm/C
49 60 80
HDT 264 psi 275 F 118F -210F 180 F
127
PPS and PPO Physical Properties
Physical Properties
PPS PPO Nylon 6,6
Optical Opaque Opaque Translucent to opaque
Tmelt 290 C 250 C 255 C – 265 C
Tg 88 C 110 – 140 C
H20
Absorption
> 0.02% (24h) 0.01% (24h) 1.0-2.8% (24h)
8.5% (Max)
Oxidation
Resistance
good good good
UV Resistance fair fair Poor
Solvent
Resistance
Poor inaromatics
Poor inaromatics
Dissolved by phenol &formic acid
Alkaline
Resistance
good good Resistant
Acid
Resistance
poor good Poor
Cost $/lb $2 $1.80 $1.30
128
PPS and PPO Processing Properties
Processing Properties
PPS PPO Nylon 6,6
Tmelt 290 C 250 C 255C – 265C
Recommended Temp Range (I:Injection, E:Extrusion)
I: 600F – 625F I: 400F – 600FE: 420F – 500F
I: 500F – 620F
Molding Pressure 5 – 15 kpsi 12 - 20 kpsi 1 -20 kpsi
Mold (linear) shrinkage (in/in) 0.007 0.012 – 0.030 0.007 – 0.018
• PPS frequently has glass fibers loaded up to 40% by weight
»Tensile strength = 28 kpsi, tensile modulus = 2 Mpsi, HDT = 500F
•PPO is frequently blended with PS over a wide range of percentages.
(Noryl from G.E.)
129
Section Review – Polyesters is one of many heterochain thermoplastics, which has
atoms other than C in the chain.
– Polyesters includes unsaturated (thermosets), saturated and
aromatic thermoplastic polyesters.
– Condensation polymerization for Polyester
– Thermoplastic polyesters have ester(-C-O) repeating link
– Linear and aromatic polyesters
– Most thermoplastic LCP appear to be aromatic copolyesters
– Effects of reinforcements on polyester
– Effects of moisture environment on nylon
– If cooled rapidly from the melt to a Temp below Tg, PET solidifies
in amorphous form. If reheated PET acquires 30% crystallinity
– PET has rigid group of (CH2)2 ; PBT has more flexible (CH2)4
– Copolyester chain is less regular than monopolyester chain and as
a result has less crystallinity
O
130
Section Review
– PEEK and PEK are aromatic polyketones.
– Ketone groups have R - O - R functionality.
– Chemical structure of PEEK and PEK depicts benzene - oxygen -
benzene in backbone.
– PEEK and PEK are used primarily in applications requiring high
temperature use and chemical resistance.
– AP2C is a special version of PEEK with 68% continuous carbon
fiber.
– Polyphenylene materials are plastics with the benzene ring in the
backbone.
– PPO and PPS are characterized as heterochain thermoplastics,
which has atoms other than C in the chain.
– PPO and PPS are made via Condensation Polymerization.
– PPS frequently has glass fibers loaded up to 40% by weight.
– PPO is frequently blended with PS over a wide range of
O
131
Section Review • Major Topics
– Vinyl is a varied group- PVC, PVAc, PVOH, PVDC, PVB.
– PVC is the leading plastic in Europe and second to PE in the US.
– PVC is produced by addition polymerization from the vinyl chloride monomer in a head-
to-tail alignment.
– PVC is partially crystalline (syndiotactic) with structural irregularity increasing with the
reaction temperature.
– PVC (rigid) decomposes at 212 F leading to dangerous HCl gas
X1
– Vinyls have (CH2CX2) repeating link
– PS is Amorphous and made from addition polymerization
– PC is amorphous and made from condensation polymerization
– Effects of reinforcements on PP and PS
132
Section Review • Major Topics
– Isotactic, atactic, sydiotactic polypropylene definitions
– Differences between PP and PE
– Molecular Weight definition and forms (Weight Average, Mw, and
Number Average, MA )
– Polydispersity definition and meaning
– Relation between Molecular weight and Degree of Polymerization
(DP)
– Mechanical, physical, and processing properties of PP,
Polybutylene, and polymethylpentene
– PP is produced with linear chains
133
Section Review
• Key Terms and Concepts
– Polyolefin
– Molecular weight
– Number average molecular weight, weight average MW
– Polydispersity
– Polymer shrinkage
– Polymer blends
– Tensile Modulus
– Izod Impact Strength
134
Homework Questions #21. Define Polyvinyls, PS, PP, HDPE, chemical structure.
2. Compare the density PVC, PVB, PS, and PVDC which is higher/lower than PP.
3. Compare the density of HDPE, LDPE, UHMWPE, LLDPE to PP?
4. What is the tensile strength of PP with 0%, 30% glass fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of PVC, PS, PP, LDPE and HPDE to look like:
Tensile
Strength,
Kpsi
Tensile Modulus, Kpsi200 500
10
50
xLDPE
xHDPE
135
Homework Questions #2
6. Four typical Physical Properties of PVC are Optical = _______, Resistance to
moisture= ______ , UV resistance= _____, solvent resistance=_______
7. The Advantages of PP are ________, ________, _______, and __________.
8. The Disadvantages of PP are ________, ________, _______, and __________.
9. Glass fiber affects PP by (strength) ________, (modulus)________,
(impact)_______, (density) __________, and (cost) ____________.
10. Two Blends PVC are ___________, and __________.
136
Homework Questions #2
11. Define Polypropylene chemical structure
12. Does commercial PP have Isotactic, atactic, sydiotactic form.
13. If MW of PP is 200,000, what is the approx. DP?
14. Polydispersity represents the distribution of _______and _____
15. Density of PP is _____ which is higher/lower than HDPE.
16. PP mechanical properties are higher/lower than LDPE and HDPE
17. Plot tensile strength and tensile modulus of PP, LDPE and HPDE to look like the
following
Tensile
Modulus,
Kpsi
Tensile Strength, Kpsi2 5
10
50
xLDPE
xHDPE
137
Homework Questions #2
18. Four typical Physical Properties of PP are Optical = _______, Resistance to moisture= ______ , UV resisance= _____, solvent resistance=_______
19. The Advantages of PP are ________, ________, _______, and __________.
20. The Disadvantages of PP are ________, ________, _______, and __________.
21. Glass fiber affects PP by (strength) ________, (modulus)________, (impact)_______, (density) __________, and (cost) ____________.
22. Five polyolefins are ________, ________, _______, ______, and __________.
138
Homework Questions
1. Define PEEK, PPO and PPS chemical structures.
2. How are the properties of PEEK and PPS alike?
3. Density of PEEK is _____, PPS is _____ , and PPO is
_____ , which is higher/lower than PBT and nylon?
4. What is the tensile strength of PEEK with 0%, 30% glass
fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of PEEK, PPO,
PPS, PET, PBT, Nylon 6, PP, LDPE and HPDE to look like
the followingTensile
Modulus,
Kpsi
Tensile Strength, Kpsi2 5
10
50
xLDPE
xHDPE
139
Homework Questions
6. Four typical Physical Properties of PEEK are Optical =
_______, Resistance to moisture= ______ , UV resistance=
_____, acid resistance=_______
7. The Advantages of PEEK are ________, ________,
_______, and __________.
8. The Disadvantages of PEEK are ________, ________,
_______, and __________.
9. How are the properties of PPO and PPS alike? How are they
different?
10. What are 3 advantages that Nylon has over PPO and
PPS?_________________________________
________________________________________________
_.
140
Homework Questions
1. Define PBT and PET chemical structure.
2. Why was Carothers not successful in developing polyesters?
3. Density of PET is _____ which is higher/lower than PBT
and nylon?.
4. What is the tensile strength of PET with 0%, 30% glass
fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of PET, PBT,
Nylon 6, PP, LDPE and HPDE to look like the following
Tensile
Modulus,
Kpsi
Tensile Strength, Kpsi2 5
10
50
xLDPE
xHDPE
141
Homework Questions
6. Four typical Physical Properties of Polyester are Optical =
_______, Resistance to moisture= ______ , UV resistance=
_____, acid resistance=_______
7. The Advantages of Polyester are ________, ________,
_______, and __________.
8. The Disadvantages of Polyester are ________, ________,
_______, and __________.
9. Glass fiber affects Polyester by (strength) ________,
(modulus)________, (elongation)_______, (density)
__________, and (cost) ____________.
10. What affect does the copolymer have on the crystallinity of
polyesters and
why?_________________________________
142
Homework Questions
1. Define Nylon 6,6 and Nylon 6 and Nylon 6,12 chemical
structure
2. If MW of PA is 50,000, what is the approx. DP?
3. Density of PA is _____ which is higher/lower than PP.
4. What is the tensile strength of nylon 6,6 with 0%, 30% glass
fibers? What is the tensile modulus?
5. Plot tensile strength and tensile modulus of Nylon 6, PP,
LDPE and HPDE to look like the following
Tensile
Modulus,
Kpsi
Tensile Strength, Kpsi2 5
10
50
xLDPE
xHDPE
143
Homework Questions
6. Four typical Physical Properties of PA are Optical =
_______, Resistance to moisture= ______ , UV resisance=
_____, solvent resistance=_______
7. The Advantages of PA are ________, ________, _______,
and __________.
8. The Disadvantages of PP are ________, ________,
_______, and __________.
9. Glass fiber affects PA by (strength) ________,
(modulus)________, (impact)_______, (density)
__________, and (cost) ____________.
10. Two Aromatic PA are ___________, and __________.
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