Question

What is difference between chain growth and step growth polymerisation?

Answer 1

Hey !!

CHAIN GROWTH POLYMERISATION

• Concentration of monomers disappears early in reaction.
• Reaction is fast and polymer is formed at once.
• There is very little change in the molecular mass throughout the reaction.
• Increase in reaction time increases the yield but molecular weight is affected a little.
• Only one repeating unit is added at a time.
• Reaction mixture contains only monomer, polymer and growing chain.

STEP GROWTH POLYMERISATION

• Concentration of monomers decreases steadily throughout the reaction.
• The polymer is formed in gradual steps.
• The molecular mass of polymer increases throughout the reaction.
• Long reaction time is required to get high molecular mass polymer.
• Any two steps species present can react.
• All molecular species are present at any stage.

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