Polymers

Question 1

Thermosetting polymers

Answer 1

Will harden irreversibly she genuinely create their own heat
Cannot be softened or reshaped with heat once hardened
Will not melt , will char

Polymer molecules •
Polymer chains -
Chain links |

Regular rigid structure
Cannot be reformed
Not recyclable
Made from resin and hardener

Question 2

Thermo softening polymers

Answer 2

Polymer molecules
Polymer chains
Van der wal forces - invisible forces of attraction

Random chain structures - not regulated
Polymers chains held together by bonds of attraction - not physical
Called van der wal forces - invisible

Question 3

Examples of thermosoftening polymers

Answer 3

Acrylic 
Abs 
PVC 
Hdpe 
Polypropylene

Question 4

Acrylic

Answer 4

Stuff ,hard but scratches easily 
Durable 
Good electrical insulator 
Machines and polishes well 
Brittle in small sections 

Used for signs
Wash basins or baths
Covers for car lights aircraft canopies and windows

Question 5

ABS - acrylic butandiene styrene

Answer 5

Impact resistance and toughness - used in protective headgear

Pigments can be added , og colour is translucent ivory to white - used in Lego bricks

Resistant to aqueous acids and alkalis- used in drain pipes

Light weight
Can be injection moulded and extruded
Can be recycled

Question 6

PVC - Polyvinyl chloride

Answer 6

Weather and chemical resistant
And Gas Impermeable - used for packaging for toiletries, food, drink and confectioneries

Strong abrasion resistance
Rigid or flexible

Question 7

HDPE - High density Polyethylene

Answer 7

High resistance to chemicals

Tough and hard wearing
Good barrier to water - used in unbreakable bottles

Rigid - very thin packaging sheets

Lightweight- can float
Can be coloured

Question 8

Examples of thermosetting plastics

Answer 8

Epoxy resins
Urea formaldehyde
Polyester resin

Common properties:
Stiff/ hard but brittle
Good electrical insulator

Question 9

Epoxy resins

Answer 9

Good electrical insulator
Used in printed circuit boards

Resists chemicals well
Hard but brittle unless reinforced

Also used in casting and encapsulation adhesives and bonding of other materials

Question 10

Urea formaldehyde

Answer 10

Stiff
Hard
Strong
But brittle

Good electrical insulator - used for electric fittings

Also used for handles, control knobs and adhesives

Question 11

Polyester resin

Answer 11

Stiff
Hard
But brittle unless laminated
Good electrical insulator

Resists chemicals well - used in boats

Also used for car bodies , bonding of other materials as well as for casting and Encapsulation