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Polymerisation. Objectives: Be able to describe how some products of cracking are turned into plastics. Create a model of polyermisation . Fractional Distillation. High temp. Catalyst. Cracking. alkane. alkene. shorter alkane. Thermal decomposition. Uses of alkenes.
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Polymerisation Objectives: • Be able to describe how some products of cracking are turned into plastics. • Create a model of polyermisation.
High temp Catalyst Cracking alkane alkene shorter alkane Thermal decomposition
Uses of alkenes Plastics Ethanol
Monomer Addition polymerisation Polymer
Formation of plastics (polymers) • Many small molecules join together to form a larger molecule. • The small molecule or monomer is the alkene. • The large molecule is the polymer (plastics). • Mono = one • Poly = many • ‘Mer’ = unit • The process is called addition polymerisation.
Model • A scientific model is a way to represent an idea.
Create a model of polymerisation using the cut out molecules Once you have done that, in your books show how ethene is turned into polyethene
Making polymers • The monomer ethene forms the polymer poly(ethene) or polythene.
Match up the monomer to the polymer and its uses.
Key question: What effects the properties of polymers? The monomer it is made from The conditions its made under
HDPE – High density polythene • Made from ethene molecules using a catalyst at 50˚C. LDPE – Low density polythene • Made from ethene molecules using very high temperatures and a bit of oxygen.
Below are some properties that polymers may have: Flexible Stretchy Hard-wearing Select 2 properties that it would be useful for the following uses. • Pair of tights • Dental fillings • Hiking jacket • Pan handle • Goldfish tank Non-conductor of heat Transparent Stiff Flexible Waterproof
Plenary: With your partner.... Discuss: • One thing you’re confident about. • One thing you’re unsure about. • One thing you’d like to know.