Making a polyester
3 marks · EasyThe formation of a polyester involves two different types of monomers.
Name the two types of organic molecules needed to make a polyester.
Describe how these two monomers react together to form a polyester.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Diol and dicarboxylic acid
(b) The diol and dicarboxylic acid react at their functional groups. Each reaction forms an ester link, joining the molecules with the elimination of a small molecule (such as water). This repeats to give a long-chain polyester.
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Names both diol and dicarboxylic acid (accept clear alternatives).
M1 (b) · 1 mark · Describes the two monomers reacting at their functional groups to form ester links, with loss of water.
B2 (b) · 1 mark · States that the reaction repeats, producing a long-chain polyester (reference to polymer chain or repeated linking).
Worked solution
a) The two types of molecules are a diol and a dicarboxylic acid.
b) The hydroxyl groups (–OH) of the diol and the carboxyl groups (–COOH) of the dicarboxylic acid react together. Each reaction forms an ester link and releases water. This process repeats to make a long polyester chain.