Q.Which of the following polymers contains acrylonitrile as monomer?

Ziegler-Natta catalyst (triethylaluminium + TiCl4) is the classic catalyst for addition (coordination) polymerisation of olefins, giving stereoregular, high-density polymers. Correct option (a).

Olefins such as ethene and propene undergo addition polymerisation on a Ziegler-Natta catalyst (a combination of an aluminium alkyl like Al(C2H5)3 and a transition-metal halide like TiCl4). It enables low-pressure polymerisation and gives linear, high-density and stereoregular polymers.

• Zeolite is a shape-selective catalyst (cracking, isomerisation), not olefin polymerisation. …

Orlon is polyacrylonitrile, the addition polymer of acrylonitrile (vinyl cyanide). Correct option (a).

Orlon (also called Acrilan/PAN) is formed by addition polymerisation of acrylonitrile, CH2=CH-CN. The repeating unit contains the nitrile (-CN) group, and the polymer is used for synthetic fibres/wool substitutes.

• Dacron is a polyester (from ethylene glycol + terephthalic acid).
• Teflon is from tetrafluoroethene. …