Polyesters

Question 1

what are polyesters?

Answer 1

polymers that contain ester links that join together repeating units

Question 2

what does condensation polymerisation involve?

Answer 2

• usually involves two different types of monomer
• the monomers react together and bonds form between them, making polymer chains
• each monomer has to contain at least two functional groups, one on each end of the molecule
• each functional group can react with the functional group of another monomer, creating long chains of alternating monomers - for each new bond that forms, a small molecule is lost e.g. water

Question 3

when do polyesters form?

Answer 3

when dicarboxylic acid monomers and diol monomers react together - the dicarboxylic acid monomers contain two carboxylic acid (-COOH) groups and the diol monomers contain two alcohol (-OH) groups

Question 4

what is formed when a carboxylic acid group reacts with an alcohol group?

Answer 4

an ester link

Question 5

each time an ester link is formed…

Answer 5

a molecule of water is lost

Question 6

are polyesters biodegradable?

Answer 6

• some polyesters are biodegradable
• biodegradable polyesters, known as biopolyesters, can be broken down by bacteria and other living organisms in the environment over time
• this means they decompose and don’t stay in landfill forever, reducing the polymers’ pollutant effect