Kinetic Modeling of “Living” and Conventional Free Radical Polymerizations of Methyl Methacrylate in Dilute and Gel Regimes

Abstract

A universal methodology to obtain the termination rate coefficients in free radical polymerization as a function of conversion and chain length was used to describe the RAFT-mediated “living” radical polymerization (LRP) and conventional free-radical polymerization (FRP) of methyl methacrylate (MMA) up to the glass regime. A composite termination model determined previously using the reversible addition-fragmentation chain transfer−chain length dependent−termination (RAFT-CLD-T) method, based on conversion (x) and chain length (i) dependent termination rate coefficient, (x), data, was the key parameter in obtaining accurate fits to the experimental rate and molecular weight data. Two kinetic modeling approaches were used in this study: (i) model 1: full chain length distributions; (ii) model 2: “method of moments”. Both approaches gave excellent agreement with experimental results for the evolution of conversion and MWD for RAFT-mediated polymerizations and accurately described the kinetics after the g...