Modeling of organocatalized atom transfer radical polymerization of methyl methacrylate

Author(s)

Ana Gabriela Belmonte Assalin

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2021-03-01

Examining board members

Roniérik Pioli Vieira; Rejane Barbosa Santos; João Lameu da Silva Júnior

• Advisor: Roniérik Pioli Vieira

Abstract

Atom Transfer Radical Polymerization (ATRP) is known as the most powerful controlled polymerization technique. This technology provides a synthesizing ability of well-defined functional polymers with a wide range of monomers at low temperatures and also with an impurities-resistant process. However, transition metal catalysts, which are necessary in the process, lead to the polymers contamination. The high cost of purification makes the ATRP end up losing competitiveness in terms of industrial applications. Fortunately, a recent discovery of Organocatalyzed Atom Transfer Radical Polymerization (O-ATRP) has emerged as a potential alternative to solve this problem. The model-based approach is a very effective strategy in studies of polymerization kinetics, as it allows a low cost, fast and versatile analysis, including the mechanism study, a process simulation and the prediction of properties results, such as molar masses and dispersity. Thus, the main objective of this work was to understand this new process, using mathematical modeling to evaluate the kinetics of O-ATRP and properties of poly(methyl methacrylate). For mathematical modeling, mass balances were developed for each species in a batch reactor. From these balances the method of moments was used to obtain the conversion of monomer, molar mass and dispersity. The models were solved in a computer program developed in Mathcad and the modeling validation consisted of a simulated profile analysis and data from the literature, using scatter plots. A parametric sensitivity analysis was carried out in order to study the effect of the kinetic constants used in the process. With this, the results showed that the propagation constant has greater influence on the system, therefore, higher values of this constant showed greater effect in relation to conversion, without directly affecting molar mass and dispersity. The chain transfer and termination constants between primary radicals were neglected in the process. Finally, with the analysis of the effect of the proportion of reagents, it was inferred that the higher the concentration of initiator and catalyst there was a greater conversion of monomer without loss of control of the polymerization. In addition, terminal functionality remains high, indicating adequate reaction conditions and a high rate of polymerization (AU)

• FAPESP's process: 19/02468-6 - Modeling of organocatalized atom-transfer radical polymerization of metyl methacrylate
• Grantee: Ana Gabriela Belmonte Assalin
• Support Opportunities: Scholarships in Brazil - Master