Q.Explain the term copolymerisation and give two examples.

Copolymerisation is the polymerisation reaction carried out using a mixture of two (or more) different monomer species simultaneously, so that the resulting polymer chain (a copolymer) contains more than one type of repeating unit, distributed alternately, randomly, or in blocks along the chain.

Example 1 — Buna-S: copolymerisation of buta-1,3-diene ($CH_2=CH-CH=CH_2$) and styrene ($C_6H_5-CH=CH_2$) in the ratio 3:1.

Example 2 — Buna-N: copolymerisation of buta-1,3-diene and acrylonitrile ($CH_2=CH-CN$) in the presence of a peroxide catalyst. …

Define copolymerisation as polymerising a mixture of two distinct monomers, then give two textbook addition-copolymer …

• Confusing copolymerisation (using two different monomers) with simply blending/mixing two already-formed polymers.
• Giving only one example when two are asked for. …