1.2-Performance characteristics of polymers

Question 1

Granules (stock form)

Answer 1

a small particle of plastic

Question 2

Sheet (stock form)

Answer 2

Large, flat sections of polymer in varying thickness

Question 3

Film (stock form)

Answer 3

Very thin sheet polymer

Question 4

Rods and other extruded forms, tubes, bars

Answer 4

• Rods and extruded forms can be a specific designed shape
• Bar- sold form, square or round
• Tube- hollow cross section, square, rectangular or round

Question 5

Foam (stock form)

Answer 5

Solid form made by including air or other gases, such as styrofoam from expanded polystyrene

Question 6

Powder (stock form)

Answer 6

Very fine granule of powder

Question 7

Characteristics of polymers

Answer 7

• majority of polymers made via fractional distillation of crude oil (non renewable resource)
• synthetic polymers made from crude oil and take ages to degrade
• polymers are ‘self finishing’ (can be pigmented during manufacture process for colour)
• can be split into three types- thermoplastics, thermoset polymer and elastomer

Question 8

What are thermoplastics

Answer 8

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

Question 9

What is a thermoset polymer

Answer 9

a material that, when heated, undergoes a chemical change where the molecules form rigid cross links
-cannot be reheated and reshaped

Question 10

What is an elastomer

Answer 10

a material that, at room temperature, can be deformed under pressure
-upon release of pressure, it will return to its original shape

Question 11

Thermoplastics- Low density polyethelence (LDPE)- properties and characteristics

Answer 11

• tough, good chemical resistance, weather proof, available in translucent
• squeezy detergent bottles, toys, bin liners, food trays

Question 12

Thermoplastics- High density polyethelence (HDPE)- properties and characteristics

Answer 12

• available in translucent form, weather proof, tough, good chemical resistance
• chemical drums, jerry cans, toys, bowls

Question 13

Thermoplastics- Polypropylene (PP)- properties and characteristics

Answer 13

• available in translucent, good chemical resistance, tough, good hinge property
• rope, folders, folio cases

Question 14

Thermoplastics- High impact polystyrene (HIPS)- properties and characteristics

Answer 14

• hard, rigid, available in translucent, tough

- yoghurt pots, refrigerator linings, single use drinks cups

Question 15

Thermoplastics- Acrylonitrile butadiene (ABS)- properties and characteristics

Answer 15

• tough, hard, available in opaque

- telephone handsets, rigid luggae, domestic appliances, calculator cases

Question 16

Thermoplastics- Polymethacrylate (PMMA)- properties and characteristics

Answer 16

• tough, hard, good chemical resistance, available in translucent
• car light castings, CNC laser cut items, baths

Question 17

Thermoplastics- Nylon- properties and characteristics

Answer 17

• tough, corrosion resistant, good tempertaure resistant

- bearings, gears, curtain rails, cable ties

Question 18

Thermoplastics- Rigid polyvinyl chloride (uPVC)- properties and characteristics

Answer 18

• rigid, opaque, tough, hard, good weathering resistence, good chemical resistance
• window frames, external foors, guttering and downpupes for buildings

Question 19

Thermoplastics- Flexible polyvinyl chloride (PVC)- properties and characteristics

Answer 19

• available in translucent, tough, flexible, good weathering resistance
• hose pipes, cable insulation, medical grade tubing, seat coverings

Question 20

Thermoset polymers- Urea formaldehyde (UF)- properties and uses

Answer 20

• hard, heat resistant, good electrical insulator

- electrical fittings, adhesives

Question 21

Thermoset polymers- Melamine formaldehyde (MF)- properties and uses

Answer 21

• hard, opaque, tough, heat resistant, food safe

- decorative laminates, picnic ware

Question 22

Thermoset polymers- Polyester resin- properties and uses

Answer 22

• rigid, heat and chemical resistant, brittle

- castings, lay up process for GRP, chair seats

Question 23

Thermoset polymers- Epoxy resin- properties and uses

Answer 23

• rigid, clear, hard, tough

- adhesives, surface coatings, cardiac pacemakers

Question 24

Elastomers- Natural rubber (polyisophrene)- properties and uses

Answer 24

• high tensile strength, long elongation, good hardness

- automotive industry e.g. tyres, tubes, hoses, belts

Question 25

Elastomers- Butadiene rubber (BR)- properties and uses

Answer 25

• tough, excellent wear resistance against friction, good thermal resistance against friction
• vehicle tyres, shoe soles, toys

Question 26

Elastomers- Neoprene (polychloroprene rubber)- properties and uses

Answer 26

• good thermal resistance, toughness, good oil and chemical reistance, good abrasion resistance
• wetsuits, laptop cases, hose covers, transmission belts

Question 27

Elastomers- silicone- properties and uses

Answer 27

• good flexibility at low temperatures, poor abrasion resistance, good weather resistance, good lubricating qualities, electrical insulator
• flexible ice cube trays, beakeware, cooking utensils, mould making, medical uses