High conversion copolymerization, 2. Styrene/maleic anhydride copolymer composition studies

The free radical initiated copolymerization of styrene with maleic anhydride at high conversions is studied. The data of the fractional conversion of the comonomers, of the fractional copolymerization rate, of the instantaneous and cumulative composition of the copolymer for the copolymerization of an equimolar mixture of styrene and maleic anhydride in ethyl methyl ketone (at 60°C) and in 1,4-dioxane (at 120°C) up to high conversions as a function of the reaction time (resp. conversion) are presented. Negligible differences at 60°C, but significant ones at 120°C were found between the experimentally measured fractional compositions and those calculated according to the integrated form of the copolymer composition equation (Mayo-Lewis equation), using the published values for the copolymerization reactivity ratios.