1. Plastic Coding System CodeType of PlasticCharacteristicsApplication 1 PET Polyethylene Terephthalate PET Clear, tough, solvent resistant, often used as a fibre Carbonated soft drink bottles, pillow and sleeping bag filling, textile fibres 2 HDPE High Density Polyethylene HDPE Hard to semi-flexible, waxy surface, opaque, melts at 135 o C Crinkly shopping bags, freezer bags, milk bottles, bleach bottles, buckets, rigid agricultural pipe, milk crates 3 VUnplasticised Polyvinyl Chloride UPVC Hard, rigid, can be clear, can be solvent welded Electrical conduit, plumbing pipes and fittings, blister packs, clear cordial and fruit juice bottles 3 VPlasticised Polyvinyl chloride PPVC Flexible, clear, elastic, can be solvent welded Garden hose, shoe soles, cable sheathing, blood bags and tubing, watch straps 4 LDPELow Density Polyethylene LDPE Soft, flexible, waxy surface translucent, melts at 80 o C, scratches easily. Garbage bags, squeeze bottles, black irrigation tube, black mulch film, garbage bins 5 PPPoly-propylene PP Hard but still flexible, waxy surface, melts at 145 o C, translucent, withstands solvents. Very versatile material with many applications Potato crisp bags, drinking straws, microwave ware, plastic kettles, plastic garden settings, baby baths, plastic hinged lunch boxes 6 PSPolystyrene PS Clear, glassy, rigid, brittle opaque, semi-tough, melts at 95 o C. Affected by fats and solvents Plastic cutlery, imitation ‘crystal glassware’ low cost brittle toys. 6 EPSExpanded Polystyrene EPS Foamed, light weight, energy absorbing, heat insulating Foamed polystyrene, hot drink cups, hamburger take-away clamshells, foamed meat trays, protective packaging for fragile items 7 OTHER Resins Laminates Acrylic Nylon Poly-Urethane Poly-Carbonates Phenolics Furniture fittings, wheels and castors. Fence posts, pallets, outdoor furniture and marine structures

2. Plastic Sample No. PHYSICAL APPEARANCE What does it look like? Opaque, soft crinkly, crumbles, coloured, bendable, breakable, tears…………. DENSITY Floats or Sinks? Yes/No BURN TEST Heat a nail and touch it to the plastic. Does it melt, smoke, or burn? FLAME TEST Hold sample in tongs, heat in the Bunsen flame in the fume hood Does it drip or shrink? Does it melt, or make black smoke? 1 2 3 4 5 6a 6b 7 List the sample you are testing. Use the information you have discovered and the flow chart to work out what your plastic samples are

3. Plastic Packaging Key Is it white(or pale coloured) Soft foam that crumbles easily Yes Expanded Polystyrene NO Does is float in water? PUSH IT WELL UNDER WATER, MAKE SURE ALL BUBBLES ARE REMOVED Is it thin, clear film that tears Easily, without stretching, leaving smooth edges? # You may have to start the tear by snipping into the edge with scissors Is it clear as glass, flexible and tough? Yes NO Yes Polypropylene NO Polythene Yes NO Heat a small piece of the plastic until it fumes (NOT BURNS).Test the fumes with damp blue litmus Paper. Does the plastic give off acid fumes? i.e. does the litmus turn red? Yes NO Polyvinyl Chloride PVC Polystyrene Polyester START

4. Polymers & Plastics Many things these days are made from POLYMERS Polymers include materials like it as a noun to mean a group of materials that are glass, rubber and cellulose. The largest group of polymers are the materials that we usually call PLASTICS. The work ‘plastic’ can have two meanings. Usually we use it as a noun to mean a group of materials that are ‘made of plastic’. But we can also say that a material has ‘plastic’ properties. For example plasticine has plastic properties but it is NOT a plastic. When you make a plasticine model you use force to change the shape of this ‘modelling clay’. Once it has taken on a new shape the plasticine keeps it; it does not go back to its old shape. (Compare plastic properties with elastic properties – elastic materials do go back to their original shape.) Many polymers have plastic properties, especially when they are heated. The term ‘plastic’ is now usually used for the polymers produced by chemical synthesis. Synthesis means a building-up of complex things from simpler, smaller parts. Polymers are chemical compounds. The molecules of polymers are very long chains of repeating units. They are made by joining together small molecules called MONOMERS. The chemical reaction which joins the monomers to for polymers is called POLYMERISATION. Monomers are made to polymerise by the use of pressure, heat and catalysts. THERMOPLASTICS are polymers that can be heated and formed into new shapes. When heated, the long-chain molecules slide past each other allowing the plastic to soften. This is very useful in the manufacture of plastic articles. It also allow material to be reclaimed for new uses. Thermoplastics include polythene, polystyrene, PVC, Nylon…… THERMOSETS are polymers that can be formed into shapes only once using heat and pressure. After that, they do not soften when heated. They are stable up tyo much higher temperatures and will eventually decompose without melting. The reason is that, on the first heating, cross- links for between the molecule chains preventing softening on future occasions.