Emulsion copolymerization of styrene and acrylated methyl oleate

Abstract

In this work, the emulsion copolymerization of styrene and acrylated methyl oleate (AMO), a monomer derived from oleic acid (OA), has been evaluated. Reactions exhibiting high monomers conversions were successfully performed, leading to the formation of very stable polymer lattices, whose average particle size is kept unchanged for relatively high storage times. The average molar masses determined by gel permeation chromatography showed to be very dependent on the amount of AMO in the reaction medium, presenting experimental values within the range from 280 000 to 39 000 g mol−1 with molar mass dispersity ranging from 4 to 2 when the AMO fraction in the reaction medium was increased to 40 wt%. The nucleation rate was affected by AMO in such way that an increase in AMO concentration must be accompanied by an increase in initiator concentration, which leads to the reduction of the average molar masses of the copolymer. The thermal analyses of the polymer materials showed that the glass transition temperature decreased with increasing amount of AMO in the copolymer chains.Practical applications: The use of vegetable oils and their derivatives as precursor monomers in polymerization reactions has increased each day due to their renewable origin. Among them, OA deserves special attention due to the high availability and ease of chemical modification, mainly when the double bounds are considered. Results showed that AMO could be incorporated at high ratios in emulsion polymerization reducing the glass transition temperatures of the copolymer. The polymer lattices also showed good storage stability.