Kinetic Study of CuBr2/PPh3 Catalytic ARGET ATRP and Its Application in Acrylate Emulsions Preparation

Activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) represents a significant advancement in reversible deactivation radical polymerization, offering substantially reduced catalyst loadings while maintaining precise control over molecular architecture. This study presents a comprehensive kinetic investigation of CuBr₂/PPh₃ catalytic ARGET ATRP of ethyl acrylate, methyl methacrylate, and butyl acrylate with particular emphasis on its application in the preparation of acrylate emulsions. The results demonstrate that increasing the ligand concentration effectively enhanced both monomer conversion and the apparent propagation rate constant. The polymerization rate reached a maximum at a catalyst to ligand molar ratio of 1 : 2. At a polymerization temperature of 90°C, both monomer conversion and apparent growth rate attained their peak values, yielding an apparent activation energy of 56.5 kJ/mol. Furthermore, increasing the reducing agent concentration resulted in concomitant increases in both monomer conversion and copolymerization rate. This catalytic system was successfully applied to the emulsion polymerization of three monomers and stability of the isolated emulsions was explored. It is demonstrated that pretty low catalyst loading CuBr₂/PPh₃-catalyzed ARGET ATRP could be a plausible practical method for the preparation of acrylate emulsions.