Question

SBR (GRS, Buna-S, Cold Rubber) is obtained by free radical copolymerisation of :

• A. $70\%$ Buta - $1,3$ - diene and $30\%$ phenly ethene (styrene)
• B. chloroprene and styrene
• C. vinly-acetylene and styrene
• D. isoprene and $1,3$ - butadiene

Answer 1

The correct option is A $70\%$ Buta - $1,3$ - diene and $30\%$ phenly ethene (styrene)

Styrene rubber or SBR (Styrene butadiene rubber) or GRS (Government controlled styrene rubber) is prepared by the copolymerization of buta - $1,3$ - diene ($70\%$) and styrene ($30\%$). The name Buna-S is made up of Bu which indicates Buta - $1,3$ - diene, NA is for Sodium ($Na$) and S indicates Styrene.

Option A is correct.