Polyesters

Question 1

what is a polyester?

Answer 1

a polymer made of lots of molecules joined together in a chain by ester groups

Question 2

how do you make a polyester?

Answer 2

you need to mix two types of monomer:

• dicarboxylic acid (has -COOH at both ends)
• diol (has -OH at both ends)

lots of monomers can then join up into a very long, alternating chain

Question 3

why is this type of polymerisation called condensation polymerisation?

Answer 3

because each time a monomer joins the end of the chain, a water molecule is lost

Question 4

how do you work out the structure of the repeat unit?

Answer 4

highlight the OH in the -COOH groups and the H in the -OH groups, then get rid of them and join what’s left together

Question 5

what are biopolyesters?

Answer 5

• some polyesters are biodegradable, which means microbes such as bacteria and fungii can use enzymes to break down the polymer into its monomers and use them as an energy supply
• this is a good thing, because it reduces our reliance on landfill and incineration to dispose of used polyesters