Roniérik Pioli Vieira

Optimization of reaction conditions in functionalized polystyrene synthesis via ATRP by simulations and factorial design

Atom-transfer radical polymerization (ATRP) is a powerful reversible-deactivation radical polymerization technique that provides polymers with several macromolecular architectures. Global optimization of this type of system is often difficult due to the mathematical models complexity. Based on that, the purpose of this paper is to provide a simplified optimization method to determine the best reaction conditions in bulk styrene ATRP initiated by 2,2,2-tribromoethanol. A kinetic model, with experimental validation, was used to generate the response variables in a full 23 factorial design. Thus, an easy statistic modeling was employed to optimize reaction conditions. It was also performed a traditional global dynamic optimization to prove that our approach could be accomplished without considerable errors. Finally, we demonstrated that the optimum conditions can be obtained in an easy and uncomplicated way, allowing extend it to any polymeric system.

Simulation of temperature effect on the structure control of polystyrene obtained by atom-transfer radical polymerization

This paper uses a new kinetic modeling and simulations to analyse the effect of temperature on the polystyrene properties obtained by atom-transfer radical polymerization (ATRP). Differently from what has been traditionaly published in ATRP modeling works, it was considered “break” reactions in the mechanism aiming to reproduce the process at high temperatures. Results suggest that there is an upper limit temperature (130 °C), above which the polymer architecture loses the control. In addition, for the system considered in this work, the optimum operating temperature was 100 °C, because at this temperature polymer with very low polydispersity index is obtained, at considerable fast polymerization rate. Therefore, this present paper provides not only a tool to study ATRP processes by simulations, but also a tool for analysis and optimization, being a basis for future works dealing with this monomer and process.