Polymer Processing
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Transcript of Polymer Processing
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Polymer ProcessingReferencesBillmeyer* Ch. 17, 18Elias** Ch. 14
*Textbook of Polymer Science 2nd Ed.Wiley-Interscience, New York (1962,1971)**An Introduction to Polymer ScienceVCH, New York (1997)
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Legacy Lecture of Fall 2000This lecture was contributed by the MS-I class of Fall 2000. Left to RightNhan Thai, Lee Madsen, Lu Ziqiang, Zu Yichuan, Nikhil GuptaSimon Mwongela, Andrea Dupre, Mariah McMasters, Vera Verdree, Angela DavisNadia Edwin, Thomas Morgan, Amy Morara, Xiaoming Liang Missing: Justin Mecomber
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Not just one polystyreneSelected PS grades from BASF. VEF=very easy flow; HM=high molar mass; HR = heat resistant. Taken from Elias, Ch. 14. Processing engineers select grades using data such as these, perhaps relyingon such numbers more than the molecular data such as M or Rg that chemists are used to. Note how completely unmolecular!What molecular properties do you suppose correspond to EF, HR or HM?
Physical Property
Test Condition
Unit
Grade
VEF
EF
HM
HR
HM-HR
Viscosity Number
?
mL/g
74
96
119
96
119
Heat Distortion Temp B
0.45 MPa
oC
80
82
84
98
98
Heat Distortion Temp B
1.8 MPa
oC
70
72
76
86
86
Vicat Temp A
10 N
oC
88
88
92
106
106
Vicat Temp B
50 N
oC
84
84
89
101
101
Young's Modulus
1 mm/min
MPa
3150
3200
3150
3200
3250
Creep Modulus
1000 h
MPa
?
2300
2830
2700
2850
Tensile strength
5 mm/min
MPa
46
50
56
50
63
Fracture elongation
5 mm/min
%
1.5
2
2
2
3
Impact strength
-30 to + 23 oC
kJ/m2
6
9
11
10
13
Notched Impact Strength
-30 to + 23 oC
kJ/m2
2
2
2
2
2
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Back to the BeginningEarly in the course, we tried several ways to categorize polymers, such as condensation vs. addition, etc. From a processing point of view, the main classes are:
Thermoplastic: the resin is heated to make a viscous liquid and then processed into a usable object without much additional chemistry. Example: polyethylene, polystyrene.
Thermoset: upon heating, further reaction occurs to make molecules set up into a useful product. Chemistry occurs, so these are sometimes called reactive polymers. The resin may be provided as either small molecules or prepregspartially polymerized stuff. Example: polyurethanes, phenol-formaldehyde, melamine-formaldehyde, epoxy glue.
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Compression MoldingRedrawn by Nikhil Gupta and Yichuan Xu from Billmeyer Fig. 17-1
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Injection MoldingRedrawn by Ziqiang Lu and Andrea Dupre from Billmeyer Fig. 17-2Feed hopper,contains polymer pellets
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Blow Moldinge.g. milk bottleRedrawn by Thomas Morgan from Billmeyer Fig.17-3
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Four-roll calender Based on Billmeyer Fig. 17-4 (references Winding 1961)
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A Plastics Extrudere.g. tubingRedrawn from Billmeyer 17-5 by Xiaoming Liang
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Fiber DrawingRedrawn by Nadia Edwin from Billmeyer 18-5 (Riley 1956)
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Melt SpinnerRedrawn by Lee Madsen From Billmeyer 18-4, citing Riley 1956
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Dry Spinning of Fibersfrom a Solution
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Wet Spinning (e.g. Kevlar)
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Cotton
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Dry Spun Acetate
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Need tenacity vs. ElongationPlota Student Project like Billmeyer 18-1
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Fiber properties for textile useAdapted from Billmeyer Table 18-1.
Chemical
Physical
Biological
Fabric Qualities
Stability to:
Acid
Base
Bleach
Solvents
Heat
Sunlight
Aging
Mechanical
Tenacity
Elongation
Stiffness
Flex cycles
Abrasion resistance
Work recovery
Tensile recovery
Toxicological
Dematological
Resistance:
Bacteria
Molds
Insects
Appearance
Drape
Hand
Luster
(Kawabata machine can measure)
Flammability
Thermal
Melting Point
Softening Point
Tg
Tdecompose
Permeability
Can protect against biotoxins?
Comfort
Warmth
Water sorption
Moisture retention
Wicking
Ease of drying
Electrical
Surface resistivity (static)
Sensors
Can detect pathogens?
Stability
Shape
Shrinkage
Felting
Pilling
Crease resistance or retention
Wetability