Effect of structure of vinyl esters on radical polymerization

A study has been made to clarify the correlation between the structures of vinyl esters and their radical reactivities by applying the following TAFT's equation: From the results of the copolymerizations of seven vinyl esters (M2) with vinyl chloride (M1) it was found that the relative reactivities (1/r1) of vinyl esters towards the poly(vinyl chloride) radical are dependent on the polar substituent constants (σ*) of the acyl groups, but not on their steric substituent constants (Es). The ρ* and δ values found were 0.094 ± 0.009 and 0, respectively. It was also observed that the Q and e values for vinyl esters tend to increase with their σ* values. Moreover, from the determination of 1.2‐glycol units in the poly(vinyl alcohols) derived from the poly(vinyl esters), it was shown that the proportion of a head‐to‐head addition in homopolymerizations of vinyl esters decreases with increasing σ* values, except for the case of vinyl benzoate.