Substituent effects in free radical copolymerization of substituted styrenes with acrylates and methacrylates

Relative reactivity ratios have been determined for o ‐chlorostyrene with five lower acrylates and methacrylates, respectively, and for methyl acrylate with a number of substituted styrenes in free‐radical copolymerization. Analysis of the data shows that: (a) acrylates are less reactive than methacrylates with o ‐chlorostyrene; (b) length of the side chain has little or no effect in methacrylates, but its effect is pronounced in acrylates with respect to their reactivity ratios; (c) chlorine substitution in the side chain of either acrylates or methacrylates has a significant influence on the reactivity ratio; (d) relative reactivity ratio data for methyl acrylate with substituted styrenes fail to show the expected relationship between monomer structure and resonance theory, inductive effect and, consequently, the Hammett σ values.