Chemistry Macromolecules

download Chemistry Macromolecules

of 16

  • date post

    11-May-2015
  • Category

    Technology

  • view

    13.591
  • download

    3

Embed Size (px)

Transcript of Chemistry Macromolecules

  • 1.MacromoleculesSynthetic Polymers

2. Macromolecules s Macromolecules are large molecules built up from many small repeating units (monomers) joined together by covalent bonding s Different macromolecules are made up of different units and/or different linkages s Generally, 2 types of macromolecules synthetic and natural 3. Definitions s A monomer is a small molecule that may be covalently bonded to other monomers to form a polymer s A polymer is the macromolecule formed when monomers are covalently bonded to form a long chain of molecule s Polymerisation is the process whereby a large number of small molecules (monomers) join together to form a macromolecule 4. Synthetic polymers s Polyethene s Polyvinyl chloride s Teflon s Polystyrene s Perspex s Nylon s Terylene 5. Addition Polymerisations Addition polymerisation occurs when monomer units join together by breaking double or triple bonds without losing any molecules or atoms s Eg. Alkenes undergo addition polymerisation whereby the double bonds in alkenes are changed to single bonds 6. Formation of polyethenefrom ethene n can be between 10 000 and 30 000 7. More addition polymersName & formula of Name & formula of monomer polymer Propene Polypropene ChloroethenePolychloroethene (vinyl chloride)Polyvinyl chloride Tetrafluoroethene Polytetrafluoroethene Teflon PhenylethenePolyphenylethene Styrene Polystyrene 8. CondensationPolymerisation s Condensation polymerisation occurs when monomer units join together by eliminating a small molecule, like water, to produce a polymer s 2 main types of condensation polymers polyamides and polyesters 9. Formation of Nylon s Made from dicarboxylic acid and diamineH-O O-H H HAMIDE LINKAGE CONH 10. Formation of Terylene s Made from dicarboxylic acid and diol s Benzene-1,4-dicarboxylic acid and ethane-1,2-diol H-OO-H H H ESTER LINKAGE COO 11. Uses of synthetic polymers Name Uses Polyethene To make plastic bags, cling film NylonTo make clothing, fishing line,parachutes Terylene To make clothing PVC To make insulator for cables, plastic raincoats Polystyrene To make polystyrene disposable boxes, light-weight packaging TeflonFor coating cooking utensils 12. Pollution caused by non-biodegradable plastics s Plastics are relatively cheap, easily shaped s Light, tough, waterproof and durable s However, cannot be decomposed by bacteria in the soil s Disposal usually by burning, and possibly produce poisonous gases s Biodegradable plastics are required to solve the problems 13. Macromolecules Natural Macromolecules 14. Examples of naturalmacromolecules s Proteins s Fats s Carbohydrates s They are the main constituents of food but with different units 15. Proteins s Built up from units of amino acids s Proteins have the same amide linkages as nylon but with different units 16. Fats and Oils s Built up from glycerol and long-chain carboxylic acids (fatty acids) s Fats are esters possessing the same ester linkages as Terylene but with different units