Recalculation of monomer reactivity considering the effect of monomer partitioning in microemulsion

From the copolymerisation data for the microemulsion polymerisation of both partially water soluble monomers ethylacrylate (EA)–methylmethacrylate (MMA) the concentration of the monomer at the polymerisation loci was calculated. While the reported copolymerisation data for the microemulsion copolymerisation of styrene (Sty)–methylacrylate (MA), monomer pair with different solubility and polarity and Sty–butylacrylate (BA), monomer pair with similar solubility and different polarity was used to calculate the monomer concentration at loci. It was inferred from the non-constancy of f′A/fA and f′B/fB ratio that the preferential site of polymerisation might be the emulsifier layer in case of Sty–MA and Sty–BA. While, based on the monomer fraction in the copolymer and the constancy of f′A/fA and f′B/fB it was concluded that microemulsion polymerisation for monomer pair EA–MMA, having similar solubility and polarity, conforms more to bulk polymerisation, where there is no preferential site of polymerisation. The loci concentration rather than feed value was used to recalculate the reactivity at the site of polymerisation. Also the loci concentration was calculated assuming their sum at the polymerisation site equal to unity.