Polymers

• Monomers= Small molecules that join together to make polymers.

  Polymers= Long chain molecules made from lots of small molecules joined together.
• Condensation polymerisation:

  Formation of long chain molecules from monomers joining together, eliminating a small molecule, such as water or hydrogen chloride.

  • Dicarboxylic acids and diols = Produces Polyesters.
  • Dicarboxylic acids and diamines= Produces Polyamides.
  • Amino acids = Produces proteins.

  Polyesters and polyamides can be broken down by hydrolysis and are biodegradable.
• • Polyesters = Terylene (PET), carboxylic link between monomers and used for rope and plastics.
  • Polyamides= Nylon, hydrogen bonding between chains, amide link (C=O-NH) between monomers. Used for clothes, fabrics and rope. Kevlar, hydrogen bonding between chains, amide link (C=O-NH) between monomers. Used for gloves and bulletproof vests.
• Addition polymerisation:

  Formation of long chain molecules from monomers joining together, with no other products.

  • Polypropene= Used for plastic packaging.
  • Polystyrene= Used for food packaging
  • Poly(chloroethene) or PVC = Used for clothes.

  Polyalkenes are chemically inert and non-biodegradable.
• Advantages and disadvantages of different methods of disposal of polymers: Landfill

  • Landfill is the most cost-effective method of waste disposal.

  VS

  • Landfill wastes land and often pollutes the land with polymers which will take hundreds of years to decompose. 
  • Some polymers leach compounds into the soil.
  • Landfills are an eyesore.
  • Landfills release methane, a very effective greenhouse gas.
• Advantages and disadvantages of different methods of disposal of polymers: Incineration

  • Saves money which regards transport as waste can be incinerated locally.
  • Prevents unsightly landfill sites.

  VS

  • Releases greenhouse gases and some toxic gases depending on the polymer incinerated.
  • Can produce gases that cause acid rain.
  • Still produces waste, which has to be sent to landfill, but this is 90% less than waste sent directly to landfill.
  • More expensive than landfill.
• Advantages of Recycling:

  • Less crude oil needed to be extracted for the production of plastics.
  • Fewer quarries and mines are needed to extract finite reserves of metal ores.
  • Economically beneficial 
  • Major industry and provides employment
• Disadvantages of Recycling:

  • Collection and transport of material to be recycled requires energy and fuel
  • Workers, vehicles and work sites need to be organised and maintained
  • Materials need to be sorted before they can be recycled which also requires energy and labour
  • Products made from recycled materials may not always be of the same quality as the original