Question

Write the mode of free radical polymerisation of an alkene. Clearly indicate the role of an initiator in it.

Answer 1

• Initiation: an initiator (e.g., peroxide or AIBN) decomposes to give free radicals, which add to the alkene, forming an active chain radical.
• Propagation: the active radical adds successive monomer molecules; the chain grows.
• Termination: two radicals combine or disproportionate, ending chain growth.
• Role of initiator: it creates the first radicals that start chains and thus controls the rate and number of polymer chains.