ADDITION POLYMERS OF ALKENES
“polymer” – Greek word “polys” = many and “meros” =
parts
Polymers – macromolecules composed of repeating structural units called monomers
GENERAL REACTION
R
R
R
R
C C
RR
C C
RR
R
R
R
R
C C C
R
R
R
R
R
RAlkene monomer
heat
pressure
Addition polymer
EXAMPLES OF ADDITION POLYMERS
CH2
CH2 n
nCH2=CH2
Ethene (ethylene) Polyethylene
CH2
CH
nnCH2=CH2
Propene (propylene) Polypropylene
CH3 CH3
YOU TRY!
Draw the polymer that would be made from the monomer vinyl chloride. What would it be called?
H2C CH
Cl
H2C CH
Cl
+
ANOTHER PRACTICE PROBLEM
Draw the polymer that would be made from the monomer styrene. What would it be called?H2C CH H2C CH+
COPOLYMERS
When two different monomers are combined by addition polymerization, a copolymer is formed. The polymer is random.
-E-P-P-E-E-E-P-P-E-P-E-E-E-P-P-P-E-P-
H2C CH2 H2C CH+
CH3
H2C
H2C
HC
CH2
H2C
CONDENSATION REACTIONS
Another method of making polymers Two compounds are combined One compound will lose a H atom and
the other will lose an –OH group. These combine to form water. Nylons and polyesters are formed by
condensation polymerization. They form in an alternating pattern.
PRODUCTION OF NYLON 66
CCH2CH2CH2CH2C
O
HO
O
OH + H NCH2CH2CH2CH2CH2CH2N
H H
H
CCH2CH2CH2CH2C
O
HOO
NCH2CH2CH2CH2CH2CH2N
H H
H + H2O
10
NATURAL VS SYNTHETIC POLYMERS The most abundant organic molecules
in the world are polymers Examples of Natural Polymers:
1. cellulose & lignan (main fibers in wood) 2. starch (stored sugar in plants) 3. chitin (fiber in the cell walls of algae,
fungi and arthropods) 4. collagen 5. DNA, RNA, and protein 6. cotton, wool, silk and flax
11
PLASTICS Plastics are a group of materials
manufactured primarily from petroleum and natural gas.
All plastics are polymers. Plastics are distinguished by their ability to
be easily formed and molded in many ways for many purposes
1907 – 1st fully synthetic polymer “Bakelite” Hard plastic used as an electrical insulator Paved the way for the >60,000 plastics
made today
12
USES OF POLYMERS
POLYMER PROPERTIES APPLICATIONS
Neoprene Chemical resistant, rubbery
Shoe soles, radiator hoses
Polyamide (nylon)
Fibrous, strong, durable
Parachutes, carpet, hosiery
polyester Fibers recover quickly after extension, moisture resistant
Filters, insulation, tire cords, Dacron, Mylar
Polyurethane Flexible foams, elastic quick-drying fibers, hard-drying films
Mattresses,Airplane wings,Spandex, Lycra,varnishes
13
USES OF POLYMERSPOLYMER PROPERTIES APPLICATIONS
Polyvinyl alcohol Colorless, water-soluble, flammable resin
Adhesives, lacquers, coatings & films
Polyvinyl chloride -Rigid when unplasticized, // flexible when placticized
Pipes, records, floor tiles, credit cards //Raincoats, shower curtains
Polyvinyl fluoride Resistant to chemicals and weathering
Protective films for siding, pipes, chemical containers
Polyvinylacetate Water-insoluble resin
Carpet backing, latex paint, adhesive & cement
14
RECYCLING PLASTIC POLYMERS
Between 1960 and 2000, the total annual solid waste in the US doubled from 80 million tons to 160 million tons
About 20% of the volume of trash is composed of plastics
Plastics, unlike paper and garden debris, are not biodegradable
Coding system identifies types of plastics so they can be categorized for recycling purposes
15
RECYCLING PLASTIC POLYMERS
All plastics with the same recycling code are made of the same polymer
The letters under the code symbol tell you from what plastic it is made
Recyclers use the codes to separate plastics into groups
16
RECYCLING PLASTIC POLYMERS INVESTIGATION
Each lab station has examples of the first 6 recycling codes.
Begin at your usual lab station. Then rotate through all stations, 1 - 6
Complete the chart for each recycling code. *Describe the plastics: are they clear, rigid, crinkly, glossy, etc
*Name some of the sample products: pop bottles, milk jugs, grocery bags, etc.
BE SURE TO NOTE THE SIMILARITIES AND DIFFERENCES AMONG THE DIFFERENT
POLYMERS
17
PLASTIC RECYCLING CODESRECYCLING CODE
POLYMER RESIN
DESCRIPTION SAMPLE PRODUCTS
PolyethyleneTerephthalate(PET or PETE)
Usually clear or green; rigid
Peanut butter jars, salad dressing & soft drink bottles
High-density Polyethylene(HDPE)
Semi-gloss, crinkly; may be hard when thick
toys; detergent, motor oil & milk containersPlastic bags
Polyvinyl chloride or vinyl (PVC-V)
Semi-rigid, glossy
Shampoo, vegetable oil bottles
Low-density polyethylene (LDPE)
Flexible, not crinkly
Grocery, bread & garment bags; shrink-wrap
18
PLASTIC RECYCLING CODESRECYCLING CODE
POLYMER RESIN
DESCRIPTION SAMPLE PRODUCTS
Polypropylene
(PP)
Semi-rigid,Low gloss
Yogurt & margarine containers, bottle tops, medicine bottle
Polystyrene(PS)
Often brittle, glossy
Coffee cups, meat trays & fast food containers, CD cases
Multi-layer plastics
Squeezable Squeezable ketchup & syrup containers
LecturePLUS Timberlake
19
RECYCLING PLASTICS
From Water Bottles to Polyester http://www.youtube.com/watch?v=zyF9
MxlcItw&feature=related
WHAT DETERMINES THE PROPERTIES OF A POLYMER?
STRUCTURE determines the properties and functions of a polymer
Stronger attractive forces between chains = stronger, less flexible polymer.
Chains able to slide past each other = flexible polymer
In polyethylene, attractive forces are weak induced dipole - dipole, will it be flexible or not?
Nylon has strong hydrogen bonds, why does this make it a strong fiber?
21
STRUCTURE OF POLYMERS
Polymers can be created with all different degrees of hardness, flexibility, strength, and other properties by controlling structural factors such as:
BranchingCross-linking
Size (molecular mass)
POLYMER CHAIN STRUCTURES
LINEAR Monomer units are linked in a chain-like
manner (like a paper clip chain)
Examples: HDPE – high density polyethylene Polytetrafluoroethylene – Teflon PP – polypropylene
Random coil – all tangled up like a plate of spaghetti
POLYMER CHAIN STRUCTURES
BRANCHED
Has short chains attached to the main chain
Tends to have less strength and lower solution viscosity compared to a linear polymer
Examples: Polyethylene Glycogen
POLYMER CHAIN STRUCTURES
CROSS-LINKED
Caused by intermolecular forces like hydrogen bonding, covalent bonds between carbon atoms, or by disulfide bridges (bonds between sulfurs)
Examples: Vulcanized rubber Curly hair – amino acids methionine and
cysteine
25
THERMOPLASTIC
80% of thermoplastic polymers are linear or branched polymers
Weak attractive forces between chains broken by warming
Change shape - can be remolded Weak forces reform in new shape when
cooled
26
THERMOSET
Extensive cross-linking formed by covalent bonds.
Bonds prevent chains moving relative to each other.
What will the properties of this type of plastic be like?
Top Related