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Polymerisation. Plastics. Plastics are substances made from alkenes. Common plastics are: Polythene or poly(ethene). Used for plastic bags. Plastics. polystyrene:. Used for damage protection in packaging and insulation. Nylon and polyester are both used in clothing. nylon. polyester.
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Plastics Plastics are substances made from alkenes. Common plastics are: Polythene or poly(ethene) Used for plastic bags.
Plastics polystyrene: Used for damage protection in packaging and insulation.
Nylon and polyester are both used in clothing. nylon polyester
Nylon and Gore-Tex® Both nylon and Gore-Tex are used in waterproof clothing such as jackets.
Nylon is... • waterproof • tough • lightweight • keeps ultraviolet light out But it does not let water vapour through, so sweat condenses.
Gore-Tex... has all the properties of nylon. But it is breathable – it allows water vapour through. Active outdoor walkers etc. do not suffer from perspiration wetness
Polymers • Plastics are examples of polymers. • Polymers are substances made of very large molecules. • The molecules are made from many smaller molecules (monomers) joined together. • The process of making a polymer is called polymerisation.
Polymerisation Most polymers are made by addition polymerisation. A catalyst and a high pressure are needed. A polystyrene plant
Making polymers The polymer poly(ethene) is made from the monomer ethene. covalent bonds ethene molecules (monomer) poly(ethene) molecule (polymer) The prefix ‘poly’ means ‘many’.
Have a go at completing the following table: polypropene styrene polychloroethene* * also known as pvc or ‘vinyl’
Polymerisation equations When ethene molecules react the double covalent bonds break. The product – poly(ethene) – is saturated. poly(ethene) ethene
Polymerisation equations Notice the repeating unit:
n Polymerisation equations So we can write the structure of poly(ethene) as:
n n n Polymerisation equations Complete the following equations: n
Draw the displayed formula for the monomer of this polymer: repeating unit