Reactivities of cis- and trans-Dimethoxyethylenes and p-Dioxene in Radical Copolymerizations

Abstract

In order to obtain further information on the reactivities of cis- and trans-isomers of 1, 2-disubstituted ethylenes of the nonconjugated type, the copolymerizations of cis- and trans-dimethoxyethylenes (DME) and p-dioxene (PD) with maleic anhydride (MAn) or maleimide (MIm) were carried out. Since DME and PD gave 1: 1 copolymers with MAn, the reactivities were compared by the overall rate:
cis-DME≥trans-DME≥PD
The reactivities with MIm radical were compared by the determination of the monomer reactivity ratios as follows (MIm=M₁).
trans-DME≥cis-DME≥PD
(1/r₁=trans-DME 5.2, cis-DME 4.5, PD 0.78)
The data indicated that there was no significant difference in reactivities between cis- and trans-isomers of DME and that DMEs were about 6 times as reactive as PD. These results were rationalized by considering the steric structure of the monomers.