Allyl polymerization. IV. Effective chain transfer in polymerization of allylic monomers

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Abstract
In addition to degradative chain transfer, effective chain transfer is characteristic of the polymerization of allylic monomers. The order of increasing effective chain transfer in a series of allyl compounds is ethyl ether < ethyl carbonate < acetate < propionate < trimethylacetate < chloride < laurate < benzoate < chloroacetate, and varies from 3% in allyl ethyl ether to 85% in allyl chloroacetate. A constant value of dM/dC is obtained in all of these cases. The decreasing order of [dM/dC]cat←0 is chloroacetate > benzoate > laurate > chloride > propionate > acetate > ethyl carbonate > trimethylacetate > ethyl ether and ranges from 108 for the chloroacetate to 6.3 for the ether. The decreasing order of DP is ethyl carbonate > acetate > propionate > benzoate > chloride > chloroacetate > laurate > trimethylacetate > ethyl ether and ranges from 14 for the carbonate to 4 for the ether. A radical displacement reaction may be operative in the polymerization of the trimethylacetate and benzoate and possibly in the case of the ethyl carbonate and ethyl ether. Considerable effective chain transfer occurs in the polymerization of allyl chloride and allyl chloroacetate as the result of hydrogen abstraction to yield halogen‐containing radicals. Effective chain transfer is predominant in the polymerization of allyll laurate, possibly through the operation of an intramolecular hydrogen transfer.