Explain addition polymerization for polystyrene.
Ans : Synthesis –
Styrene (C6H5CH=CH2) , undergoes addition polymerization to form polystyrene , --( C6H5CH=CH2)-
It is prepared by the polymerization of styrene in presence of benzoyl peroxide catalyst.
The raw materials for polystyrene are ethylene and benzene that react to form ethyl benzene, which is further processed into styrene monomer.
Polystyrene is a cheap transparent compound.
In the polymerisation, the carbon–carbon π bond of the vinyl group is broken and a new carbon–carbon σ bond is formed, attaching to the carbon of another styrene monomer to the chain.
The newly formed σ bond is stronger than the π bond that was broken, thus it is difficult to depolymerize polystyrene.