Tracer techniques for the determination of monomer reactivity ratios. II. Monomer reactivity ratios in copolymerizations with divinyl monomers

Monomer reactivity ratios have been determined for styrene (r1 = 0.35)–ethyleneglycol dimethacrylate (r2 = 0.65) and styrene (r1 = 0.65)‐m‐divinylbenzene (r2 = 0.60), a tracer technique being used to determine the copolymer composition. The data for these divinyl monomers give intersect plots with three different monomer ratios which determine the reactivity ratios. The usual two‐component copolymerization equation is modified by the use of 2M2 for the M2 term where M2 is the mole percent of the divinyl monomer in the charge. Similar data for p‐divinylbenzene do not locate a unique set of reactivity ratios. It is concluded that the copolymerization behavior of symmetrical divinyl monomers in which the vinyl groups do not interact can be evaluated through use of the two‐component copolymerization equation.