AQA A-level DT polymers

Thermoplastic

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

Thermosetting polymer

A material which when heated, undergoes a chemical change whereby the molecules form rigid cross links.

Elastomer

A material which at room temperature can be deformed under pressure and then upon release of the pressure, will return to its original shape.

Natural Bio-polymers

made from natural materials such as cellulose, starch and polysaccharides

synthetic bio-polymers

made from renewable resources but are chemically engineered to break down more quickly.

Oxy-degradable polymer

the polymer breaks down into a fine powder with exposure to oxygen, subsequently degraded by microorganisms

hydro-degradable polymer

breaks down with exposure to water

LDPE

-low density polyethylene, thermoplastic

HDPE

high density polyethylene, thermoplastic

HIPS

High Impact Polystyrene, thermoplastic

ABS

Acrylonitrile Butadiene Styrene, thermoplastic

PMMA

polymethyl methacrylate, thermoplastic

PET

polyethylene terephthalate, thermoplastic

nylon

nylon, thermoplastic

PVC

flexible polyvinyl chloride, thermoplastic

Polyethylene terephthalate (PET) is a

thermoplastic

PET characteristics

recyclable, tough, available in transparent form, can be pigmented. Used in drinks bottles.

UF

urea formaldehyde, thermoset

MF

Melamine formaldehyde, thermoset

Polyester resin

Polyester resin, thermoset

Epoxy resin

Epoxy resin, thermoset

MF is a

thermosetting polymer

MF characteristics

high melting point, chemical resistant, hard wearing, can be pigmented. Used in kitchen worktops

Natural rubber

elastomer

neoprene

elastomer

polybutadiene

elastomer

silicone

elastomer

neoprene characteristics

elastomer, can stretch and fit tightly, good degradation resistance, can be pigmented, used in wetsuits.

Problems with the use of Bio-polymers

-produce methane gas when they decompose.

-can take high temperatures to decompose and may leave behind toxic residues.

-cannot be recycled- contribute to throw-away culture.

Photodegradable polymer

can decompose with exposure to UV light

Photodegradable polymer uses

- used in the agriculture industry as a sheet which covers crops and prevents weed growth. this decreases the need for herbicide.

-holds water in the ground and insulates, extending the growing season.

Oxy-degradable polymer characteristics

the length of time taken to degrade can be programmed during manufacture and ranges from a few months to a few years.

Hydro-degradable polymer characteristics and uses

-tend to break down more quickly than Oxy-degradable polymers.

-used as an additive in detergent sachets used in washing machines.

Corn starch Polymer

-Biopolymer made from high starch vegetables such as corn and potatoes.

-It is used in packaging products, straws, vending cups and bags

Biopol

-Natural biopolymer made from potato starch.

-Used in single use food items, such as bowls and cutlery.

Polylactic Acid (PLA)

-Synthetic Biopolymer, made from corn kernels or cane sugar, which is fermented to produce lactic acid, then synthesised to produce PLA.

-Used in single use bottles, carrier bags, plant pots and 3D printing.

Glycolide

-Synthetic Biopolymer, which is fully compostable and PLA/ cellulose based.

-Used in food film, packaging wrap, bin bags.

LDPE properties and uses

-very tough, good chemical resistance, weatherproof, low level of rigidity.

-safe working temperature 65degrees.

Uses:

-detergent bottles, toys, carrier bags, general packaging.

HDPE properties and uses

-Available in translucent form, weatherproof, tough, good chemical resistance.

-Safe working temperature: 65degrees

Uses:

chemical drums, jerry cans, toys, long-life carrier bags, buckets, bowls.

Polypropylene (pp) properties and uses

-Good chemical resistance, tough, good fatigue resistance.

-safe working temperature: 100degrees.

Uses:

rope, folders, medical equipment

High Impact Polystyrene (HIPS) properties and uses

-tough, high impact strength, rigid, good electrical insulator

-safe working temperature: 70degrees

Uses:

yoghurt pots, refrigerator linings, toilet seats, instrument control knobs.

Acrylonitrile Butadiene Styrene (ABS) properties and uses

-extremely tough, hard, opaque

-safe working temperature: 80degrees.

Uses:

rigid luggage, domestic appliances, computer housings

Urea formaldehyde (UF) properties and uses

hard, heat resistant, electrical insulator, brittle

safe working temperature: 80degrees

Uses:

electrical fittings, adhesives

Melamine Formaldehyde (MF) properties and uses

Hard, opaque, tough, heat resistant, chemical resistant

safe working temperature: 130degrees

Uses:

decorative laminates, buttons

Natural Rubber (polyisoprene) properties and uses

high tensile strength, low elongation, good hardness, electrical insulator, good cold resistance.

Uses:

tyres, tubes, hoses, gaskets, belts, balloons, toys, footwear

Butadiene rubber properties and uses

tough, excellent resistance against friction, thermal resistance.

Uses:

tyres, shoe soles, toys, conveyor belts, hoses

Silicone

thermal resistant, tough, chemical and oil resistant, weather resistant.

Uses:

ice cube trays, machinery lubricant, sealant