Acrylic-alkyd hybrids: Secondary nucleation, particle morphology, and limiting conversions

Abstract

The chemical incorporation of an unsaturated alkyd into an acrylic polymer created via miniemulsion polymerisation was studied. The variation of the number ratio of polymer particles to initial droplets with conversion, and changes in individual monomer conversions with increasing alkyd levels were the main quantities used to study the effect of increasing alkyd quantity in the hybrid system. Homogeneous nucleation was more significant in systems rich in the more hydrophilic methyl methacrylate (MMA). Changes in particle morphology with monomer conversion, as well as limited monomer conversion were observed. The results emphasize the importance of proper pairing of the miscibility between the specific acrylics and alkyds used in these hybrid polymers. The polymerization of miniemulsions of acrylic monomer/alkyd mixtures is studied. It is shown that complete conversion can only be obtained if secondary nucleation is allowed to occur at high alkyd contents. In addition, it is demonstrated that the choice of initiator can have a significant impact on particle morphology and the quality of the resulting films.