Question

Q.5 [10 Marks] What are the differences between the mechanism of free radical and coordination polymerization?

Answer 1

Solution:

Difference between mechanism of free radical polymerization and coordination polmerization are,

Free radical polymerization	Coordination polymerization
1. It is the polymerization reaction where initiator is added to the monomer unit resulting in the formation of free radical center in monomer unit	1. It is the polymerization reaction where complex catalyst is added to the monomer unit resulting in the formation of metal-carbon bond in monomer unit.
2. In this polymerization reaction where second, third and fourth monomer units are added with generated free radical monomer unit consecutively resulting in the formation of large chain radical.	2. In this polymerization reaction where second, third and fourth monomer units are added with generated metal-carbon bond in monomer unit, consecutively resulting in the formation of large chain metal-carbon bond.
3. In this polymerization reaction where termina-tion of free radical after long propagation is takes place by the following possible way.	3. In this polymerization reaction where termination of large chain metal-carbon is terminated by the transfer of hydrogen atom from monomer or from active hydrogen containing compound.
4. Free radical center due to addition of initiator in monomer unit.	4. Metal-carbon bond formation due to addition of catalyst in monomer unit.
5. Example is decomposition of benzoyl peroxide in presence of sun light or heat form free radical as initiator.	5. Using this process(Zeiglar-Natta catalyst) of polymerization isoprene produces only stereospecific Cis-1,4-polyisoprene