Remark on the paper by R. L. Herbst, Jr., and R. E. Martin, entitled “relative reactivities of polymer radicals in vinyl polymerizations” (original) (raw)

Herbst and Martin' find that the relative reactivities of polymer radicals can be described by the Q' and e constants of the parent monomers. I n our general opinion regarding copolymerization,2 a monomer of the styrene type, for instance, is reactive b u t its radical is rather stable, while, on the other hand, vinyl acetate is unreactive as the monomer and is unstable as the radical. This does not coincide with the conclusion of Herbst and Martin. Before we attempt to make these relations clear, it will be necessary to note that there is a discrepancy in their report. In of their article, Q' values are assumed to be the values of Q in Alfrey and Price's scheme, though Q' values defined by them as q/RT are not the same as Q defined as exp { -q / R T ] . Also the dimension of k, is not moles/l./sec., as stated in the same figure, but I./moles/sec.