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)

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

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

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.

Compression MoldingRedrawn by Nikhil Gupta and Yichuan Xu from Billmeyer Fig. 17-1

Injection MoldingRedrawn by Ziqiang Lu and Andrea Dupre from Billmeyer Fig. 17-2Feed hopper,contains polymer pellets

Blow Moldinge.g. milk bottleRedrawn by Thomas Morgan from Billmeyer Fig.17-3

Four-roll calender Based on Billmeyer Fig. 17-4 (references Winding 1961)

A Plastics Extrudere.g. tubingRedrawn from Billmeyer 17-5 by Xiaoming Liang

Fiber DrawingRedrawn by Nadia Edwin from Billmeyer 18-5 (Riley 1956)

Melt SpinnerRedrawn by Lee Madsen From Billmeyer 18-4, citing Riley 1956

Dry Spinning of Fibersfrom a Solution

Wet Spinning (e.g. Kevlar)

Cotton

Dry Spun Acetate

Need tenacity vs. ElongationPlota Student Project like Billmeyer 18-1

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