CONICET | Buscador de Institutos y Recursos Humanos

Living radical, or controlled, polymerization has rapidly evolved during the past decade as an attractive alternative for synthesizing polymers with controlled structure. This technique has a relatively low sensitivity to impurities and requires mild operating conditions. At the same time, it offers great control over polymer structure. Narrow or multimodal molecular weightdistributions can be obtained in this way. It has also proved capable of producing different chain architectures, such as block, graft, star and brush copolymers. Most applications of this process are carried out in batch or semibatch operation. However, as a result of the discontinuous nature of those operations important delays in production are introduced. On the other hand, the use of tubular reactors offers the possibility of preparing homo and copolymers with tailor-made molecular structure in a continuous process. In a controlled polymerization process using thistype of reaction, the polymer quality variables interact in a complex way with the design and operating variables. Furthermore, the number of these interrelated variables is very large. Therefore, a mathematical predictive tool is a very important aid in the process operation, for instance for analyzing potential process scenarios and designing the process for tailor-made copolymers. In this work, a mathematical model of a nitroxide-mediated living radical copolymerization in tubular reactors is presented. In particular, copolymerization of alpha methyl styrene and of methyl methacrylate with styrene is considered. The model is able to predict the overall copolymer MWD, sequence length distribution (SLD), average compositions, averagemolecular weights and monomer conversion as a function of reactor length.

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