Kinetic Study of the Free Radical Copolymerization of Methyl Methacrylate with 2-Perfluorooctyl Ethyl Methacrylate by Quantum Computational Approach

Abstract

Fluorinated copolymers with perfluoroalkyl side chains have widespread use in applications requiring superior technology due to their unique surfacial properties. Kinetic analysis of copolymerization of fluorinated acrylates with conventional acrylates is necessary to synthesize such copolymers efficiently. However, kinetic investigation of such reactions are limited in the literature due to the experimental difficulties. In this study, the kinetics of copolymerization of methyl methacrylate with 2-perfluorooctyl ethyl methacrylate in toluene medium using AIBN initiator was investigated using quantum chemistry postulates as an alternative to experimental methods. Reaction rate constants (kp) for propagation were determined using transition state theory. A terminal effect models were used to examine four different addition reactions involving monomeric and dimeric radicals and monomers for both self-and cross-propagation. Reactant and product conformations were optimized with a DFT method using PBE0 function. The Evans-Polanyi relationship was used to calculate the rate of self-and cross-propagation of monomers. The results showed that the reactivity ratio of 2-perfluorooctyl ethyl methacrylate was found to be higher than that of methyl methacrylate. In addition, it was observed that the reaction conditions caused the random polymer structure due to the different rate constants in self and cross propagation.