Question

Polymerisation of buta - $1,3$ - diene by free radical mechanism gives___________.

• A. trans - $1,4$ - Polybutadiene
• B. cis - $1,4$ - Polybutadiene
• C. Polyvinyl polyethene
• D. Polyallyl polythene

Answer 1

Answer: (A), (B), (C)

The correct options are
A trans - $1,4$ - Polybutadiene
B Polyvinyl polyethene
C cis - $1,4$ - Polybutadiene

$1,3$ - Butadiene is an organic compound that is a simple conjugated diene hydrocarbon (dienes have two carbon-carbon double bonds).
Polybutadiene forms by linking many $1,3$ - butadiene monomers to make a much longer polymer chain molecule. In terms of the connectivity of the
polymer chain, butadiene can polymerize in three different ways, called cis, trans and vinyl.
The cis and trans forms arise by connecting the butadiene molecules end-to-end, so-called $1,4$-polymerisation. The properties of the resulting isomeric forms of polybutadiene differ. For example, "high cis" - polybutadiene has a high elasticity and is very popular, whereas the so-called "high trans" is a plastic crystal with few useful applications. The vinyl content of polybutadiene is typically no more than a few percents. In addition to these three kinds of connectivity, polybutadienes differ in terms of their branching and molecular weights.
Hence, options A, B & C are correct.