Ch. 15 Characters, Applications & Processing of Polymers

Question 1

3 main behaviours

Answer 1

Elastic - Fracture ( brittle polymers), Elastic - Plastic (Plastic polymers), Totally elastic (Elastomers)

Question 2

Temp is Proportional to :

Answer 2

E ( inversely), TS (Inversely) , %El

Question 3

E goes from

Answer 3

0.17 - 5 Gpa

Question 4

Elongation goes up to

Answer 4

%1200

Question 5

Viscoelastic

Answer 5

Rubbery solid with combined elastic + viscous behaviour

Question 6

Example of viscoelastic

Answer 6

Silly Putty

Question 7

Deformation types of Semicrystalline Polymers

Answer 7

Elastic & Plastic

Question 8

Effects of plastic deformation on polymers

Answer 8

Chains slide, amorphous regions elongate, crystalline regions tilt

Question 9

Effects of elastic deformation on polymers

Answer 9

Bond stretching, chain bending

Question 10

Necking gets a)stronger or b)weaker

Answer 10

Stronger, chain alignment occurs

Question 11

Pre-deformation by drawing
increases…

Answer 11

E and decreases Ductility (%El)

Question 12

Pre deformation by necking is reversible by

Answer 12

annealing

Question 13

Strength is influenced by

Answer 13

Temp, strain rate, molecular weight, degree of cross links, crystallinity, drawing

Question 14

Deformation of elastomers occur

Answer 14

crosslinked chain (bending)

Question 15

Tm & Tg increase by

Answer 15

Chain Stiffness

Question 16

Polymerization Methods

Answer 16

Addition & Condensations

Question 17

Addition process

Answer 17

Monomer is initiated, propagation of reaction, termination

Question 18

Condensation process

Answer 18

Two molecules added to form repeat unit, byproduct often formed

Question 19

Polymer additives

Answer 19

Additives, plasticizers, stabilizers, lubricants, colourants, flame retardants