Polymers

Question 1

what is addition polymerisation?

Answer 1

when molecules (under the right conditions) containing carbon-carbon double bonds can join together to produce very long chains. Part of the double bond is broken and the electrons in it are used to join neighbouring molecules

Question 2

what is polymerisation?

Answer 2

the joining of lots of little molecules (monomers) to make one big molecule (polymer)

Question 3

what two types of poly(ethene) are there?

Answer 3

low density (LDPE) and high density (HDPE)

Question 4

what can LDPE poly(ethene) be used for?

Answer 4

thin film to make polythene bags - it is very flexible but not very strong

Question 5

what can HDPE poly(ethene) be used for?

Answer 5

to make plastic bottles e.g. milk bottles

Question 6

what are the uses of poly(propene)

Answer 6

this is stronger than poly(ethene) so can be used to make ropes and crates

Question 7

what are the uses of poly(chloroethene)

Answer 7

it is quite strong and rigid - can be used for drainpipes and replacement windows, it can be made flexible by adding ‘plasticisers’ and is then useful for sheet floor coverings and clothing but these polymers don’t conduct electricity and PVC can be used for electrical insulation

Question 8

what are the uses of nylon?

Answer 8

used in textiles and the fibres are also used in ropes, nylon can be cast into solid shapes for cogs and bearings in machines etc.