Guest Seminar - Crosslinking Copolymerization in a Continuous Stirred Tank Reactor (CSTR)
Free-radical crosslinking copolymerization of vinyl and divinyl monomer is a typical reaction system that leads to cause gelation. Conventional gelation theory has been developed for the closed systems (batch reactors) that do not involve inflow and outflow of substances. In this study, the Monte Carlo simulation for the vinyl/divinyl copolymerization in a continuous stirred tank reactor (CSTR) is carried out, aiming at extending the gelation theory to an open system. I will present a simple formula representing the gelation condition in a CSTR. Then, the molecular weight distribution (MWD) at the gel point condition is examined. It has been believed that the power-law MWD is formed at the gel point, and the power exponent falls in a category of universality in critical phenomena, and therefore, it cannot be changed. In this talk, I will show that the power exponent can be changed and controlled by using a CSTR.
Prof. Hidetaka TOBITA is Professor of Department of Materials Science and Engineering at University of Fukui, Japan. He received his Bachelor’s and Master’s degree in Chemical Engineering in 1982 and 1984, respectively, from Kyoto University, Japan. After working in Kao Corporation (Japan), he went to study at McMaster University, Canada, in 1987 and received his Ph.D. in 1990, under the supervision of Prof. A. E. Hamielec, who is one of the founding fathers of Polymer Reaction Engineering but passed away a year ago. (A special memorial issue will be published next month in The Canadian Journal of Chemical Engineering.) The external examiner for his thesis, entitled “Crosslinking Kinetics in Free-Radical Copolymerization” was late professor W. H. Stockmayer who is a pioneer of the gelation theory, well known for the Flory-Stockmayer theory. He has been a member of the International Advisory Board of “Macromolecular Theory and Simulations” and “Macromolecular Reaction Engineering”.