addition polymers

• polymerisation - long molecules formed from lots of small molecules called monomers joined together. usually needs high pressure and a catalyst
• plastics are made of polymers. usually carbon based and their monomers often alkenes.
• addition polymers are made from unsaturated monomers, which have a double covalent bond
• unsaturated monomer molecules are alkenes
• alkenes can open their double bonds and join together to form polymer chains. this is addition polymerisation
• lots of ethene molecules can react together to form polyethene
• to draw many single ethenes, use brackets, an n to represent there can be any number of monomers, use an = sign to represent double bond. to draw polyethene's, only use 1 line to join carbon and add line sticking out
• when the monomers react in addition polymerisation reactions, the only product is the polymer, so an addition polymer contains exactly the same type and number of atoms as the monomers that formed it