polymers and plastics (technical principles)

Thermoplastic

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

Thermosetting

A polymer which when heated creates rigid crosslinks, meaning it cannot be reheated and reshaped

Elastomer

A material which at room temperature can be deformed under pressure. Once relived of that pressure, it returns to its original shape

Potato pal

A biodegradable polymer used for single use food items e.g. cutlery. It’s made from potato starch

Biopol

A biodegradable polymer used for packaging film - it is added to thermoplastics to promote degradation

Polylactic acid (PLA)

A biodegradable polymer used for single used bottles. Made from corn kernels

Lactide

A biodegradable polymer used for slow release medical patches. Compostable, water soluble

Glycolide

A biodegradable polymer used for food film. Biopolymer, compostable

Cornstarch polymers

A biodegradable polymer used for straws and disposable cutlery. Made from high starch vegetables

PHA

A biodegradable polymer used for slow release medical patches

LDPE

A thermoplastic used for food wrap film. Translucent, chemical resistance, tough. E.g. squeeze bottles

HDPE

A thermoplastic used for injection moulding and thicker plastic products such as bowls. Can be translucent, weatherproof, good chemical resistance

PP

A thermoplastic used for food containers, folders. Good fatigue resistance, chemical resistance

HIPS

A thermoplastic used for vacuum forming and to make products such as yoghurt pots. hard and rigid

ABS

A thermoplastic used for computer housing. Very tough, can be opaque, hard

Nylon

A thermoplastic used for ‘boil -in-the-bag’ food packaging. Corrosion and temperature resistance

PVC

A flexible thermoplastic used for hose pipes. Good chemical and weathering resistance. Tough

UPVC

A rigid thermoplastic used for window frames. Rigid, opaque good weathering and chemical resistance

PMMA

A thermoplastic used for car light casing. Tough, chemical resistance

Epoxy resin

A thermoset plastic adhesive and surface coating. Rigid, clear, tough, chemical resistance. Encapsulation of electrical components

Polyester resin

A thermoset plastic used for casting and lamination (lay up) for boat hulls etc. rigid, heat and chemical resistance

Melamine formaldehyde

A thermoset plastic used for decorative laminates. Tough opaque, heat and chemical resistance

Urea formaldehyde

A thermoset plastic used for adhesives and electrical fittings. Heat resistance, electrical insulator, brittle

Natural rubber

An elastomer used for tires, tubes, hoses. High tensile strength. Low elongation, electrical insulator

Silicone

An elastomer used for flexible ice cube trays. Flexibility at low temperatures and an electrical insulator

Neoprene

An elastomer used for wetsuits. Thermal and chemical resistance, tough, electrical insulator

Butadiene rubber

An elastomer used for shoe soles. Tough, thermal and wear resistance, electrical insulator

Foam board

A polymer sheet used for modelling. Two outer layers of card with foam in the middle

Fluted PP

A polymer sheet used for construction site signage. Corrugations along sheet allows it to be easily bent

Translucent PP

A polymer sheet used for packaging products. Hard to tear and water resistant. Tough polymer sheet

Styrofoam

Extruded polystyrene foam for project modelling. Dense closed cell foam

LDPE sheet

A polymer sheet used for food wrapping. Tough, transparent, good chemical resistance

Plastazote foam

A polymer used for gym and exercise mats. Flexible, impact resistance. Impermeable to liquids

Cellulose acetate

A polymer sheet used for photographic film. Transparent and naturally biodegrades

Polylactide sheet/film

A polymer used for biodegradable packaging film. Transparent, naturally biodegradable

Oxy-degradable polymer

A biodegradable polymer which breaks down to a powder with oxygen and microorganism exposure. Used in LDPE carrier bags to break them down

Photodegradable polymer

A biodegradable polymer which weakens and breaks down with exposure to UV rays. Used in agriculture to insulate the ground and extends the growing season

Hydro-degradable polymer

A biodegradable polymer which breaks down with exposure to water. Used in liquid detergent sachets