Kinetic study of free‐radical copolymerization of methyl acrylate and methyl methacrylate in benzene

Abstract
The variation of copolymerization rate with composition obtained for the system methyl acrylate (1)/methyl methacrylate (2)/benzene/2,2′‐azoisobutyronitrile using standard techniques of polymerization rate measurements has been interpreted on the basis of a penultimate effect upon the propagation reaction, giving values of s1 = 0.547 and s2 = 1.668 for the chain‐end reactivity ratios.