Polymers A2

• A polymer is a long chain molecule made from monomers joined together by covalent bonds
• Addition polymerisation is when 2 (or more) molecules produce 1 molecule (usually alkenes)
• Condensation polymerisation is when 2 (or more) molecules react to form 1 molecule and water - OH + H --> H2O
• Terylene (a polyester) is formed from benzene-1, 4 dicarboxylic acid and ethane-1, 2-diol
• Nylon 6,6 (polyamide) is formed from hexanedioic acid and 1,6- diaminohexane
• Kevlar (polyamide) is formed from benzene-1, 4 dicarboxylic acid and benzene-1, 4 diamine
• Condensation polymers (nylon, kevlar) are biodegradable and have polar bonds, so are susceptible to nucleophilic attack of water particularly. Polyalkenes have no polar bonds so are not biodegradable
• Uses of nylon: Clothing, fishnet, industrial uses such as seat belts, airbags. Uses of kevlar: Gloves, bulletproof vests, jackets
• Condensation polymers are made up of chains containing polar bonds so van der waals forces present and permanent dipole-dipole forces and hydrogen bonds between the polymer chains
• Advantages and disadvantages of using landfills to dispose polymers: Landfills are cheap/easy however requires areas of land. As waste decomposes, greenhouse gases are released. Leaks from landfills can contaminate water supplies
• Advantages and disadvantages of recycling plastics: Recycled materials reduce demand on raw materials and reduces energy consumption. However, some types of plastic cannot be recycled and there may be costs associated with collection and processing