Question

Chain-growth polymerization proceeds by which of the following mechanisms?
(A) Radical polymerization.
(B) Cationic polymerization.
(C) Anionic polymerization
(D) (a) and (b)
(E) (a), (b) and (c)

Answer 1

Hint : We know that in order to answer this question, you need to recall the mechanism chain growth polymerization and step growth polymerization. Homopolymerization involves the formation of additional polymers by the polymerization of a single monomeric species. Copolymerization involves cross linking of more than one species of monomer

Complete Step By Step Answer:
The chain growth polymer is prepared by chain growth polymerization. Among the given options, the chain growth polymer is the polymer which is fluorocarbon solid. And used as a lubricant and as a non-stick coating for cookware. It reduces friction and energy consumption of machinery. In chain growth polymerization, unsaturated monomer molecules get attached at the active site of the growing polymer chain. In this method three steps take place.
They are chain initiation then chain propagation and chain termination. Initiation of chains is done by the chain carriers that are free radical mostly. And in chain propagation, the monomer gets attached to the active center of the growing chain and forms a new chain with a new active center. Lastly in chain termination, the active center disappears, that is the active center shifts to another molecule which results in termination of propagation of the chain. Radical and cationic polymerization is chain growth polymerization in which the radical or cationic indicator initiates the mechanism. Examples are- Poly (isobutylene), Polystyrene, etc.
Therefore, the correct answer is option D.

Additional Information:
Chain polymerization has various applications in many aspects of life such as electronic devices, food packaging, catalyst carriers, medical materials and so on. At present, the world's highest yielding polymers such as polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP) can be obtained by chain polymerization. Also, some carbon nanotube polymers are used for electrical devices.

Note :
Note that there are six types of chain growth polymerization. Radical polymerizations, ionic polymerization, coordination polymerization, living polymerization, ring opening polymerization and reversible deactivation polymerization. Their industrial applications extend to water purification, biomedical devices and sensors.