Question

Difference between chain reaction and step growth polymerization

Answer 1

Step-growth (e.g. condensation) versus Chain-Growth (e.g. free radical) Polymerization. All molecules present (monomer, oligomer, polymer) can react with any other molecule. During propagation, only monomers react to the “active site” at the end of the growing chain.

Answer 2

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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