Synthetic Polymers Flashcards
What is an addition polymer?
The carbon-carbon double bonds in monomers is broken and the electrons in it are used to join to other monomers to make one big polymer.
describe some uses for polymers
Polythene: LDPE - thin film to make polythene bags HDPE - plastic bottles due to its strength and rigidity
Polypropene - ropes and crates
Polychloroethene - drainpipes or replacement windows, can be made flexible by adding plasticisers to make sheet floor coverings or clothing and electrical insulation
Why are addition polymers hard to dispose of?
It takes a very long time for them to break down because they have strong covalent bonds making them almost inert at ordinary temperatures. They are non-biodegradable.
What is condensation polymerisation?
Two monomers joining together alternately and each time they combine, a small molecule is lost.
How do you make nylon?
Hexanedioic acid and diamine join together in a condensation reaction with the loss of a molecule of water each time a new bond is formed. The OH groups in the hexanedioic acid are replaced by chlorine atoms to give hexanedioyl dichloride. The hexanedioyl dichloride is dissolved in an organic solvent which doesn’t dissolve in water. The two solutions are placed in a small beaker so that one floats onto of the other, avoiding mixing as far as possible. Nylon is formed at the boundary between the two layers.
