(488b) Kinetic Monte Carlo Simulations to Predict and Design Explicit Monomer Sequence along Copolymer Chains

Copolymers with well-defined architectures are increasingly desired in a wide range of applications as the backbone microstructure can have a dramatic impact on the properties of the polymer. For example, gradient copolymers, in which there is a gradual change in composition along the chain length, are a new class of polymeric materials that show superior blending capabilities in polymer compatibilization. Although the monomer-by-monomer sequence along the copolymer chain plays an important role in the research and potential applications of gradient copolymers, few efforts have been directed at the investigation of the explicit sequence of gradient copolymers. Here, we report the development of a simulation framework based on kinetic Monte Carlo written in house, which can predict the explicit sequence formed along each chain by tracking the growth of each individual chain instead of concentration. The framework is generally applicable to various reaction types and can incorporate differences in reactivity of different chain ends in a facile way. We use this framework to investigate the explicit sequence along the backbone of MMA/ S gradient copolymers prepared by NM-CRP in a semi-batch reactor as an example. This system serves as a good example because S/MMA copolymerization by NM-CRP has been widely studied and detailed kinetic parameters are available in literature. KMC simulations are a powerful tool to predict the explicit sequence of copolymers and can serve as a companion to experimental efforts to precisely design the sequence length along copolymer chains. Current efforts to utilize KMC simulations to develop synthesis recipes to meet design targets of sequence patterns along copolymer chains are underway.