A kinetic Monte Carlo model of a reversible addition–fragmentation chain transfer (RAFT) process is presented. The algorithm has been developed and implemented in Julia for the three main RAFT theories under current discussion (slow fragmentation, intermediate radical termination, termination with oligomers). modern programming language designed to achieve high performance numerical scientific computing. Thanks careful optimization code, it possible simulate reaction scheme short computing...

Abstract This is the first of a series works aiming at developing tool for designing “living” free radical polymerization processes in tubular reactors, order to achieve tailor‐made MWDs. A mathematical model nitroxide‐mediated controlled built and implemented predict complete MWD. It shown that this objective may be achieved accurately efficiently by means probability generating function (pgf) transformation. Comparison with experimental data good. The potential resulting optimization...

Abstract This is the first of two papers presenting a new mathematical method for modeling bivariate distributions polymer properties. It based on transformation infinite mass balances describing evolution two‐dimensional distribution using 2D probability generating functions (pgf). A key step this inversion transforms. In work, numerical methods pgfs are developed and carefully validated. The accuracy obtained with both was very satisfactory. formulas simple easy to implement....

This is the second of two works presenting a new mathematical method for modeling bivariate distributions polymer properties. It based on transformation population balances using 2D probability generating functions (pgf) and posteriori recovery distribution from transform domain by numerical inversion. Part I this work was devoted to inversion step. Here pgf analyzed. A table developed, which allows simple any typical balance equation. Three copolymerization examples are used show...

Abstract A mathematical model of RAFT polymerization processes is presented capable predicting the full molecular weight distribution (MWD) through use probability generating functions (pgf). The bivariate intermediate species calculated. able to work with three kinetic mechanisms currently under discussion for explaining observed behavior this type polymerization. For comparison purposes, population balances are also solved by direct integration resulting equations. results show that pgf...

Abstract The polymerization that IUPAC terms reversible‐deactivation radical is a controlled technique (CRP) allows producing polymers with tailored properties without the stringent conditions typical in ionic polymerization. A theoretical analysis presented of influence operating and design on product for nitroxide‐mediated copolymerization (NMP) styrene α‐methyl styrene. Several reactor configurations are analyzed, different feeding policies temperature profiles. To this end mathematical...

Good control on molecular properties, and as a consequence end-use is very important for low-density polyethylene (LDPE) manufacturers. However, the connection between architecture of polymer chains kinetic mechanism polymerization conditions still subject study. In this work, we present comprehensive model ethylene in high-pressure tubular reactors. addition to usual predictions conversion, temperature profiles, average also provides bivariate distributions such molecular-weight–long-chain...

Abstract A mathematical model for the controlled degradation of polypropylene is presented in this article. previous process was extended to predict whole molecular weight distribution modified resin. Probability generating functions were applied transform infinite set mass balance equations both polymer and radicals. The integration transformed yielded probability function transforms. These transforms then inverted with two different inversion algorithms, recovering distributions polymer....

Abstract “Living” radical polymerization is a relatively new process that can be used to prepare resins with controlled structures. In this work, mathematical model developed previously describe nitroxide‐mediated “living” polymerizations performed in tubular reactors for the optimization of and obtainment tailor‐made MWDs. Operating conditions design variables are determined help procedures order produce polymers specified It shown bimodal trimodal MWDs, given peak locations, obtained...

It has been established that the security, flexibility, and dynamic controllability of a process are inherent properties its design, which also affects economics. In this context, we employed previously developed mixed-integer optimization (MIDO) approach to perform simultaneous design control styrene polymerization reactors. Industrial- laboratory-size semibatch jacketed reactors were considered. The gPROMS/gOPT package was successfully used solve optimizations. each case, geometry,...

Abstract A rigorous dynamic model of the high‐pressure polymerization ethylene in tubular reactors is presented. The capable predicting full molecular weight distribution (MWD), average branching indexes, monomer conversion and weights as function time reactor length. probability generating method applied to MWD. This technique allows easy efficient calculation MWD, spite complex mathematical description process. used analyze responses MWD other process variables under different transition...

Abstract We review the work of our group in area mathematical modelling polymerisation reactors and processes, with emphasis prediction molecular weight distributions using probability generating functions (pgfs). apply method to a example for which analytic solution is known, show that its predictions are very accurate. also compare performance straightforward integration mass balances reacting system, showing pgf results fast calculations. end by discussing ongoing future applications...