POLYMERS

1
POLYMERS
R W Grime Ripon Grammar School
2
POLYMERS
Addition polymers
Condensation polymers
3
(No Transcript)
4
Some definitions
Polymer
long chain molecule made from lots of small
molecules joined together
Monomer
small molecules that join together in
polymerisation
Addition Polymerisation
formation of long chain molecules from lots of
small molecules joining together with no other
product
Condensation Polymerisation
formation of long chain molecules from lots of
small molecules joining together with a small
molecule (e.g. water) released
5
Addition polymers
http//users.argonet.co.uk/users/hoptonj/polymer.h
tm
6
Addition polymers
n
ethene
poly(ethene)
polythene
7
Addition polymers
n
phenylethene
poly(phenylethene)
polystyrene
8
Addition polymers
n
methyl 2-propenoate
poly(methyl 2-propenoate )
perspex
9
Addition polymers
n
methyl 2-cyanopropenoate
poly(methyl 2-cyanopropenoate)
superglue
10
Addition polymers
n
chloroethene
poly(chloroethene)
PVC
11
Addition polymers
n
tetrafluoroethene
poly(tetrafluoroethene)
PTFE / Teflon
12
Addition polymers
n
propene
poly(propene)
13
Addition polymers

• Catalysts are used for the polymerisation, and
  the exact mechanism depends on the catalyst and
  alkene (it is not electrophilic addition it is
  usually catalytic addition).

• Polyalkenes are inert, although can burn.

• As they are inert, they are non-biodegradable.

14
Condensation polymers

• Condensation polymers are polymers formed from
  condensation reactions between monomers. A small
  molecule (often water) is produced as well as the
  polymer.

• Many natural polymers are condensation polymers,
  e.g. silk, starch and DNA.

• The two main types are polyesters and polyamides.

15
Polyesters

• Esters are formed on reaction between carboxylic
  acids and alcohols.

• Polyesters are formed when dicarboxylic acids
  react with diols.

• Polyesters are hydrolysed (in the presence of
  strong acid or a specific enzyme) into their
  constituent acid and alcohol, so they are
  bio-degradable .

16
Polyesters
strong acid or specific enzyme - H2O
17
Polyesters
strong acid or specific enzyme
18
Polyesters
Kevlar
19
Polyesters

• Amides are formed on reaction between carboxylic
  acids and amines.

• Polyamides are formed when dicarboxylic acids
  react with diamines.

• Polyamides are hydrolysed (in the presence of
  strong acid or a specific enzyme), so they are
  bio-degradable.

. .
20
Polyamides
strong acid or specific enzyme
21
Polyamides
strong acid or specific enzyme