Atom transfer versus catalyst transfer: Deviations from ideal Poisson behavior in controlled polymerizations

Tuning the molecular weight distribution from atom transfer radical polymerization using deep reinforcement learning

“…We select styrene ATRP as our simulation system. Simulation of styrene ATRP may be done by solving the ATRP chemical kinetics ordinary differential equations (ODEs) in Table 1, (Weiss et al, 2015;Preturlan et al, 2016;Vieira & Lona, 2016b;Li et al, 2011) by method of moments, (Zhu, 1999) or by Monte Carlo methods. (Al-Harthi et al, 2006;Najafi et al, 2010;Turgman-Cohen & Genzer, 2012;Payne et al, 2013;Toloza Porras et al, 2013) This work directly solves the ODEs because this allows accurate track-ing of the concentration of individual polymer chains while being more computationally efficient than Monte Carlo methods.…”

“…This assumption does not bias the nature of ATRP qualitatively and has been practiced in almost all previous ATRP simulation research. (Weiss et al, 2015;Preturlan et al, 2016;Vieira & Lona, 2016b;Li et al, 2011;Vieira et al, 2015) In some of our simulations, we altered the rate constants by up to ±30% to account for possible inaccuracies in the measurement of these values and other unpredictable situations such as turbulence in the reactor temperature. We employed the VODE (Brown et al, 1989;Byrne & Hindmarsh, 1975;Hindmarsh & Byrne, 1977;Hindmarsh, 1983;Jackson & Sacks-Davis, 1980) integrator implemented in SciPy 0.19 using a maximum internal integration step of 5000, which is sufficient to achieve final MWDs with high accuracy.…”

“…We assume that the volume of the system is completely determined by the amount of solvent and the number of monomer equivalents (including monomers incorporated in polymer chains). To calculate the system volume, we use a bulk styrene density of 8.73 mol/L as reported in early works (Weiss et al, 2015) and a solvent density of 1.00 mol/L.…”

“…These kinetics are sufficiently well understood (Goto & Fukuda, 2004;Tang & Matyjaszewski, 2006) that simulations provide reliable results. (Weiss et al, 2015;Preturlan et al, 2016;Drache & Drache, 2012;Vieira & Lona, 2016a;Van Steenberge et al, 2012;D'hooge et al, 2012;Zhong et al, 2013) It is also computationally feasible to carry out a large number of simulated reactions. Figure 2 shows how the MWD evolves in a single reaction simulation, which finishes in about 1 minute on a 2.4 GHz CPU core.…”

Introduction to the special issue of Polymer on “Macromolecular Engineering” dedicated to Professor Krzysztof Matyjaszewski on the occasion of his 65th birthday

“…The first several papers describe mechanistic studies that are important in order to rationally select the reaction conditions needed for a polymerization reaction with desired outcome. The first two papers, by Balazs [45] and by Kowalewski [46], describe fundamental aspects of polymerization reactions. The paper by Gennaro [47] deals with Cu-mediated polymerization, studied by electrochemical methods and sheds light specifically on the mechanism of polymerizations taking place in the presence of metallic copper.…”