1.3 Polymers

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PINE ASH SOFTWOODS CHIPBOARD MAHOGANY MAN MADE WOODS HARDWOOD WOODS MDF OAK PLYWOOD BEECH HARDBOARD RESISTANT MATERIALS METALS ALUMINIUM POLYMERS UREA FORMALDEHYDE NON-FERROUS METALS COPPER ZINC BRASS (ALLOY) FERROUS METALS CARBON STEEL MILD STEEL MATERIALS STAINLESS STEEL THERMOSET POLYESTER RESIN ACRYLONITRILEBUTADIENE-STYRENE (ABS) ACRYLIC GCSE RESISTANT MATERIALS THERMOPLASTICS HIGH-IMPACT POLYSTYRENE (HIPS) POLYVINYL CHLORIDE (PVC) POLYETHENE @PENYRHEOLDT MATERIALS FACTSHEET Thermoplastics      MATERIALS Made up of long chains of molecules that are tangled together and have no fixed pattern When heated they become soft and can be bent, pressed or formed into different shapes. As the cool they become stiff again. This process can be repeated many times. Thermoplastics have a “memory” and when reheated will try to return to their original shape. This is known as “plastic memory” Examples are acrylic, polyethene, polyvinyl chloride (PVC), high-impact polystyrene (HIPS), acrylonitrile-butadiene-styrene (ABS) GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET Thermosetting plastics       MATERIALS These are made up from long chains of molecules that are cross linked. This means they have a very rigid molecular structure. They will soften when heated but only the first time. They can be shaped the first time, but then are set due to their rigid molecular structure. They cannot be reheated and reshaped like thermoplastics. Two examples are polyester resin and urea formaldehyde. GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET Acrylic Properties  Uses Good impact strength (tends not to shatter but to break into large pieces)  Lightweight  Good electrical insulator  durable  Ornamental fish tanks  Baths and bathroom furniture  Car indicator covers / reflectors Advantages Disadvantages  Can be recycled  Relatively soft  Excellent environmental stability  Scratches easily  Poor chemical resistance  Polishes and finishes well  Available in numerous colours MATERIALS GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET Polyethene Properties Uses  Tough  Drawer bottoms  Resistant to chemicals  Cabinet backs  Soft and flexible   Good electrical insulator Smoothing out uneven floors  Lightweight internal door cladding Advantages  Disadvantages Cheapest of all manufactured boards  Not very strong as it has no grain Aesthetics  Side very smooth and underside textured MATERIALS GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET Polyvinyl chloride (PVC) Properties Uses  Good chemical resistance  Pipes  Weather resistant   Lightweight Rainwater pipes and guttering  Good electrical insulator  Bottles  Stiff  Shoe soles  Hard   Tough Window frames and fascias  Waterproof  Water beds  Durable  Swimming pool toys  Electrical insulation tape Advantages Disadvantages  Can be recycled  Very expensive to recycle  Relatively cheap to manufacture  Dangerous fumes given off when burnt MATERIALS GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET High impact polystyrene (HIPS) Properties Uses  Tough  Food appliances  High impact strength  Toys  Rigid  Cutlery  Good electrical insulator  DVD and CD cases Advantages  Disadvantages Available in numerous colours  Can be machined and painted  Can be recycled MATERIALS  Expensive  Limited flexibility  Will not biodegrade GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET Acrylonitrile-butadiene-styrene (ABS) Properties Uses  High impact strength  Kitchenware  Tough  Camera cases  Scratch resistant  Toys  Lightweight  Car components  Durable  Telephone cases  Good resistance to chemicals Advantages  Disadvantages Available in numerous colours MATERIALS  Relatively expensive when compared to polystyrene GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET Polyester Resin Properties Uses  Good electrical insulator  Casting  Hard   Brittle Encapsulation for biological specimens  Good heat and chemical resistance  Boat hulls with fibreglass  Model figures Resists UV radiation  Adhesives  Filler materials  Advantages   Disadvantages Can be mixed with pigments to achieve a range of colours Good resistance to water MATERIALS  Contracts on curing  Can cause excess heat when too much catalyst is used GCSE RESISTANT MATERIALS @PENYRHEOLDT MATERIALS FACTSHEET Urea Formaldehyde Properties Uses  Stiff  Tableware  Hard  Worktop laminates  Brittle  Buttons  Scratch resistant  Electrical casings  Stain resistant  High tensile strength Advantages Disadvantages  Can be coloured  High surface hardness MATERIALS  Toxic fumes given off when it cures. GCSE RESISTANT MATERIALS @PENYRHEOLDT