Question
Sun July 22, 2012 By: Prkriti Gupta
 

2 differences between step growth polymerization and chain growth polymerization

Expert Reply
Sun July 22, 2012

Differences between chain growth and step growth polymerisation:

 

Chain growth polymerisation

Step growth polymerisation

*Concentration of monomers disappears early in the reaction.

* Concentration of monomers decreases steadily throughout the reaction

*Reaction is fast and polymer is formed at once.

*The polymer is formed in gradual steps.

*There is very little change in the molecular mass throughout the reaction.

*The molecular mass of polymer increases throughout the reaction.

*Increase in reaction time increases the yield but molecular weight is affected a little.

*Long reaction time is required to get high molecular mass polymer.

*Only one repeating unit is added at a time.

Any two species present can react.

*Reaction mixture contains only a monomer, polymer and growing chain.

*All molecular species are present at any stage.

 

 

 

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