Allylpolymerisation

Allylpolymerisation is a type of free-radical vinyl polymerization that involves monomers containing an allyl group. The allyl group is characterized by a double bond adjacent to a methylene group (CH2=CH-CH2-). Unlike typical vinyl monomers such as styrene or acrylates, allyl monomers exhibit a different polymerization behavior.

The primary distinction in allylpolymerisation lies in the slower rate of propagation and a significant tendency for chain transfer to the monomer. This chain transfer process involves the abstraction of a hydrogen atom from the methylene group of the allyl monomer by a growing radical chain. This results in the formation of a stable allyl radical and the termination of the growing polymer chain. The allyl radical is relatively stable due to resonance delocalization, which makes it less reactive towards further propagation.

Consequently, allylpolymerisation typically leads to low molecular weight polymers and oligomers, and the overall polymerization process is often inefficient for producing high polymers. The low molecular weight and branched structures formed are a direct result of the prevalent chain transfer reactions. Despite these limitations, allyl monomers can be used in certain applications where their unique properties are advantageous, or they can be copolymerized with other monomers to modify polymer characteristics. Research continues to explore methods to enhance the efficiency and molecular weight achievable in allylpolymerisation.