Estimation of reactivity ratios using emulsion copolymerization data

An approach for the estimation of reactivity ratios using cumulative copolymer composition–overall conversion data obtained in batch emulsion copolymerization is presented. The approach is based on an algorithm for parameter estimation in ordinary differential equations and takes into account the partition of the comonomers between the different phases present in the system. Both copolymer composition and conversion were considered to be affected by experimental errors. The method was first checked by using simulated data that included random errors. The effect of the initial guess and level of errors on the values of the estimated reactivity ratios was investigated. Once the approach was checked, it was used to estimate the reactivity ratios of the styrene–acrylonitrile system based on data obtained in unseeded batch emulsion copolymerizations of these monomers.