Step-growth Polymerization - Differences Between Step-growth Polymerization and Chain-growth Polymerization

Differences Between Step-growth Polymerization and Chain-growth Polymerization

This technique is usually compared with chain-growth polymerization to show its characteristics.

Step-growth polymerization Chain-growth polymerization
Growth throughout matrix Growth by addition of monomer only at one end of chain
Rapid loss of monomer early in the reaction Some monomer remains even at long reaction times
Similar steps repeated throughout reaction process Different steps operate at different stages of mechanism (i.e. Initiation, propagation and termination)
Average molecular weight increases slowly at low conversion and high extents of reaction are required to obtain high chain length Molar mass of backbone chain increases rapidly at early stage and remains approximately the same throughout the polymerization
Ends remain active (no termination) Chains not active after termination
No initiator necessary Initiator required

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