Question

Write chemical reactions to prepare the Dextron polymers.

Answer 1

Hint:
A polymer is a large molecule of very high molecular mass formed by the repeated combination of a very large number of one or more types of small molecules called monomers. Polymerisation is the process of the formation of a polymer from the monomers. There are two types of polymerisation:
Addition polymerisation
Condensation polymerisation

Step-by-step explanation:
Step 1:
Dextron is a polymer whose monomer units are glycolic acid and lactic acid. The process of polymerisation that is used to prepare Dextron is addition polymerisation.
Step 2:
Dextron is a biodegradable polymer which means that they break down after their planned use.
Step 3:
A polymer obtained by polymerization of more than one type of monomers is called a copolymer. The polymerisation of monomers into co-polymers is called co-polymerisation. This process proves useful in increasing the mechanical properties of a polymer.
Step 4:
Dextron is obtained by the copolymerization of glycolic acid and lactic acid.

Step 5:
So, it is a type of copolymerization with an ester linkage. In this polymerisation there is an elimination of a water molecule from both the carboxylic acid group and the linkage takes place between the oxygen atom present in the hydroxyl group of the lactic and the oxygen atom of the carboxylic group of the glycolic acid.
Hence, dextron is the copolymer of lactic acid and glycolic acid with an ester linkage.

Note: The difference between polymer and copolymer is that in polymer the same monomer unit is repeated in the larger chain whereas in case of co-polymer there are different monomer units.