General conclusions about the copolymerization of ethylene with other monomers by free radical catalysis

The behavior of ethylene in copolymerization with methyl acrylate, methyl methacrylate, vinyl acetate, diethyl fumarate, and diethyl maleate was investigated, and reactivity ratios for these systems reported. Significant deviations of all systems investigated, except ethylene–vinyl acetate, from the conventional copolymerization equation are noted and interpreted on the basis of substantial penultimate and penpenultimate effects. The consistency of the reactivity ratios developed in the systems ethylene–methyl acrylate and ethylene–methyl methacrylate with reported values for methyl acrylate–methyl methacrylate is shown by application of the relationship PabPbcPca = PacPcbPba.