Polymerization of allyl esters of unsaturated acids, 12. Cyclopolymerization of methyl 2‐methylallyl fumarate

Abstract

AbstractThe kinetics of radical‐initiated cyclopolymerization of methyl 2‐methylallyl fumarate (MMAF) was investigated and compared with the polymerization results of allyl methyl fumarate (AMF). In the former, the extent of cyclization and five‐membered ring formation were enhanced. The cyclization constants KA and KV, the ratio of the rate constant of the unimolecular cyclization reaction to that of the bimolecular propagation reaction of the uncyclized 2‐methylallylic and fumaric radicals, were estimated to be 3,1 and 3,0 mol · dm−3, respectively. On the basis of these results the formation mode and the sequence distribution of the structural units of the polymer produced are discussed in detail; the low probability for fumaric vinyl addition and high probability for the succession of cyclic structures are calculated for poly(MMAF) as opposed to those of poly(AMF). The cyclopolymerizability and five‐membered ring formation are enhanced at elevated temperature. These results are discussed from the standpoint of the steric effect on cyclopolymerizability.