1.8 Performance Characteristics of Polymers

Question 1

Give the 6 stock forms of polymers

Answer 1

• Granules
• Sheet
• Film
• Rods and other extruded form, tubes, bars
• Foam
• Powder

Question 2

Define thermoplastic polymer and give five examples

Answer 2

A material that can be reheated and reshaped repeatedly, allowing it to be recycled after its initial use.

• LDPE
• HDPE
• PP
• HIPS
• ABS
• PMMA (acrylic)
• Nylon
• uPVC
• PVC

Question 3

State three properties/characteristics of LDPE

Answer 3

• Lightweight
• Low level of rigidity
• Good chemical resistance
• Low stiffness

Question 4

State two uses of LDPE

Answer 4

• Detergent bottles
• Toys
• Carrier bags
• General packaging
• Food wrap film

Question 5

State three properties/characteristics of HDPE

Answer 5

• Tough
• Good chemical resistance
• Good stiffness
• Weather proof

Question 6

State two uses of HDPE

Answer 6

• Bottles
• Crates
• Buckets
• Bowls

Question 7

State three properties/characteristics of PP

Answer 7

• Lightweight
• Food-safe
• Good impact resistance
• Good chemical resistance
• Tough

Question 8

State two uses of PP

Answer 8

• Kitchen products
• Medical equipment
• Rope
• Folders

Question 9

State three properties/characteristics of HIPS

Answer 9

• Good impact resistance
• Good stiffness
• Lightweight
• Hard
• Tough

Question 10

State two uses of HIPS

Answer 10

• Yoghurts pots
• Refrigerator linings
• Single-use drinks cups
• Toilet seats

Question 11

State two properties/characteristics of ABS

Answer 11

• Tough

- Hard

Question 12

State two uses of ABS

Answer 12

• Safety helmets
• Toys
• Computer housing
• Rigid luggage

Question 13

State three properties/characteristics of PMMA

Answer 13

• Tough
• Hard
• Good chemcial resisatcne
• Food-safe
• Durable
• Easily machined

Question 14

State two uses of PMMA

Answer 14

• Illuminated signs
• Car light casings
• Baths
• Lightning units/covers

Question 15

State three properties/characteristics of Nylon

Answer 15

• Tough
• Corrosion resistance
• Good temperature resistance
• Low coefficient of friction

Question 16

State two uses of Nylon

Answer 16

• Gears
• Textiles
• Bearings
• Curtains rails

Question 17

State three properties/characteristics of uPVC

Answer 17

• Rigid opaque
• Tough
• Hard
• Good weathering resistance
• Good chemical resistance

Question 18

State two uses of uPVC

Answer 18

• Windows frames
• External doors
• Water service pipes
• Guttering and downpipes for buildings

Question 19

State three properties/characteristics of PVC

Answer 19

• Tough
• Good weathering resistance
• Good chemical resistance
• Flexible

Question 20

State two uses of PVC

Answer 20

• Hose pipes
• Cable insulation
• Medical grade tubing

Question 21

Define thermoset polymer and give three examples

Answer 21

A material that, when heated, undergoes a chemical change whereby the molecules from rigid cross-links. They cannot be reheated and reshaped.

• Urea-formaldehyde (UF)
• Melamine formaldehyde (MF)
• Polyester resin
• Epoxy resin

Question 22

State three properties/characteristics of UF

Answer 22

• Hard
• Tough
• Good electrical insulator
• Brittle

Question 23

State two uses of UF

Answer 23

• Electrical fittings

- Adhesives

Question 24

State three properties/characteristics of MF

Answer 24

• Hard
• Opaque
• Tough
• Heat resistant
• Food safe
• Chemical resistant

Question 25

State two uses of MF

Answer 25

- Decorative laminates - Picnic ware - Buttons

Question 26

State three properties/characteristics of polyester resin

Answer 26

- Rigid - Heat resistant - Chemical resistant - Brittle

Question 27

State two uses of polyester resin

Answer 27

- Castings - Car parts - Chair seats

Question 28

State three properties/characteristics of epoxy resin

Answer 28

- Rigid - Hard - Tough - Chemical resistant

Question 29

State two uses of epoxy resin

Answer 29

- Adhesives - Surface coatings - Cardiac peacemaker - Aerospace

Question 30

Define elastomer and give three examples

Answer 30

A material that can be deformed under pressure and that returns to its original shape when pressure is released - Natural rubber - Butadiene rubber (BR) - Neoprene - Silicone

Question 31

State three properties/characteristics of natural rubber

Answer 31

- High tensile strength - Low elongation - Good hardness - Tough - Electrical insulator - Good cold resistance

Question 32

State two uses of natural rubber

Answer 32

- Tyres - Tubes - Hoses - Footwear - Toys

Question 33

State three properties/characteristics of BR

Answer 33

- Tough - Excellent wear resistance against friction - Good thermal resistance against friction - Electrical insulator

Question 34

State two uses of BR

Answer 34

- Vehicle tyres - Shoe soles - Toys

Question 35

State three properties/characteristics of neoprene

Answer 35

- Good thermal resistance - Toughness - Good oil and chemical resistance - Excellent weather resistance - Good abrasion resistance - Electrical insulator

Question 36

State two uses of neoprene

Answer 36

- Wet suits - Laptop cases - Industrial wires insulation - Transmission belts

Question 37

State three properties/characteristics of silicone

Answer 37

- Poor abrasion resisatnce - Good thermal resistance - Good weather resistance - Good lubricating qualities - Electrical insulator

Question 38

State two uses of silicone

Answer 38

- Flexible ice cube trays - Bakeware - Cooking utensils - Medical uses as lubrication for prosthetics