Polymers

Question 1

Best polymer properties (3)

Answer 1

Cheap, Lightweight, corrosion resistance

Question 2

Difference between Engineering polymers and common

Answer 2

Improved strength and temp performance

Question 3

What are polymers?

Answer 3

Repeat units of a molecular unit

Question 4

2 Ways of creating polymers

Answer 4

Addition polymerisation, condensation polymerisation

Question 5

Addition polymerisation what

Answer 5

Monomers are joined together with no extra product created

Question 6

Condensation Polymerisation

Answer 6

To molecules are added together

Question 7

Does condensation polymerisation result in an additional product

Answer 7

yes a condensate (water, methane)

Question 8

How to measure polymer size(2)

Answer 8

Molecular weight or degree of polymerisation

Question 9

How to calculate degree of polymerisation?

Answer 9

number of monomers

Question 10

Polymer chains- Linear

Answer 10

just straight

Question 11

Polymer chains- branched, properties

Answer 11

like tree, lower density and strength

Question 12

Polymer Chains- crosslinked (properties)

Answer 12

covalent bonds- increases strength and stiffness

Question 13

What is a copolymer?

Answer 13

2 or more types of polymer

Question 14

grafted copolymer what

Answer 14

linear with one monomer and branches of the other sticking out

Question 15

Block copolymers what

Answer 15

many of one monomer and then many of the other

Question 16

Thermoplastics- structure

Answer 16

linear/ branched

Question 17

Thermoplastics- tensile properties (4) and why?

Answer 17

plastic and ductile, not strong low density cause chains can be pulled apart from each other

Question 18

Thermoplastics- heat?

Answer 18

Soften and melt

Question 19

Thermoplastics- crystal

Answer 19

mix of amorphous and crystalline

Question 20

Thermoplastics- examples

Answer 20

Polyester, polycarbonate, polyethylene

Question 21

Thermoplastics - stress strain curve why weird

Answer 21

Stress reduces after elastic region

Question 22

Why does stress strain curve weird

Answer 22

Cause the chains slide rotate disentangle and become aligned with stress direction

Question 23

Thermoplastics temperature dependence

Answer 23

Can be glassy leathery or viscous depending on temp

Question 24

Thermoplastics- creep- describe

Answer 24

under constant load sample gradually gets longer

Question 25

Thermoplastics - relaxation describe

Answer 25

under constant strain leads to stress reaction- exponential- depending on temp

Question 26

Thermosetting- chains?

Answer 26

Cross-linked

Question 27

Thermosetting- heat?

Answer 27

do no soften

Question 28

Thermosetting- properties (3)

Answer 28

Harder, more brittle and more stable

Question 29

Elastomers- chains

Answer 29

Crosslinked but specially

Question 30

Elastomers- deformation

Answer 30

no plastic deformation but still has viscoelastic relaxation

Question 31

Thermoplastics - blow moulding

Answer 31

using air to get into shape

Question 32

Thermoplastics- calendaring

Answer 32

Like making pasta

Question 33

Thermoplastics- thermoprocessing

Answer 33

using a vacuum to suck it to the right bits

Question 34

Thermoplastics-injection moulding

Answer 34

Injecting plastics into mould

Question 35

Thermosets- processing general

Answer 35

must be processed and a liquid before cross-linking

Question 36

Thermosets- compression moulding

Answer 36

using hot dies to shape and start crosslinking

Question 37

Thermosets- transfer moulding

Answer 37

put in mould and then it will polymerize through heat

Question 38

Are thermoplastics recyclable

Answer 38

yes but not easy as have to be pure and get rid of extras

Question 39

Are thermosets recyclable

Answer 39

no