Monomer Reactivity Ratios from High Conversion Copolymerization of Styrene with meta- and with para-Divinylbenzene

The copolymerization reactivity ratios for styrene/m- and styrene/p-divinylbenzene have been determined at high conversions (<35%) using the integrated form of the copolymerization equation. Values of r1 (s) = 1.11, r2 (m) = 1.00; and r1 (s) = 0.20, r2 (p) = 1.00 were obtained. These values indicate the same relative behavior but are quantitatively different from the differential data. The data confirm that the para isomer is incorporated more rapidly into the growing polymer chain than is the meta isomer.