KThumath Chemistry Saint Paul's Plastics KT7448A 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Introduction Plastics are long chain molecules made from small “monomer” units that have been joined together The process of making a plastic is called Polymerisation 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Topics of Discussion Addition Polymers are made from small unsaturated molecules. The C to C double bond opens up The carbons then bond with the next carbon atom Polymers are formed when thousands of small molecules join 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Good points Advantages of Synthetic Polymers They are cheap to make They do not corrode We can vary their properties 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's More info Disadvantages of Polymers They are not biodegradable They are made from crude oil which is finite They give off toxins when they burn Uses of Polymers Poly(ethene) – bags Poly(tetraflouroethene)- frying pans Poly(vinylchloride)- cups, foam 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Toxins When all plastics burn they release Carbon monoxide PVC – Hydrogen chloride Poly(ethene) –Carbon monoxide Nylon – Nitrogen Polyurethane foam – Hydrogen Cynanide. 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Natural Polymers Proteins - are made of thousands of small amino acid molecules Carbohydrates – are made from thousands of sugar molecules. 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Addition Polymers Made when small unsaturated molecules join. The double bond opens up. H H H H H H I I I I I I C=C + C=C + C=C ( monomers) I I I I I I H H H H H H 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Part of the polymer H H H H H H I I I I I I - C – C – C – C – C – C – I I I I I I H H H H H H CH2CH2 – REPEATING UNIT 27/05/2019 KThumath Chemistry Saint Paul's

Condensation Polymers When two monomers join water molecules are released. Proteins and Carbohydrates are condensation polymers. 27/05/2019 KThumath Chemistry Saint Paul's

KThumath Chemistry Saint Paul's Example Starch is made when many small glucose monomers join. HO – * – OH +HO –*– OH+HO –*- OH ( * = glucose molecule) HO - * - O - * - O - * - OH + 2 H2O 27/05/2019 KThumath Chemistry Saint Paul's

Thermosetting and Thermoplastics Thermoplastics can be reshaped when heated. ( most addition polymers) Thermosetting plastics crack on heating 27/05/2019 KThumath Chemistry Saint Paul's