MATHEMATICAL MODELING OF NITROXIDE MEDIATED COPOLYMERIZATION IN TUBULAR REACTORS. PREDICTION OF THE BIVARIATE MOLECULAR WEIGHT DISTRIBUTION

ASTEASUAIN, MARIANO; SARMORIA, CLAUDIA; BRANDOLIN, ADRIANA

Costa Rica

Simposio; XII Simposio Latinoamericano de Polímeros (SLAP 2010) - X Congreso Iberoamericano de Polímeros (CIP 2010); 2010

Universidad Nacional de Costa Rica

Controlled/Living radical polymerization (CRP) has experienced an exponential growth since the 1990s as an attractive route for synthesizing polymers with con-trolled structure. This process shows great potential for industrial applications because it combines advantages of  conventional free radical and living polymerizations. It can be used in heterogeneous emulsion, suspension or dispersion polymerizations. Besides, it offers a great versatility for copolymer synthesis. Manufacturing of block, gradient and graft copolymers have been re-ported.CRP in tubular reactors offers the possibility of preparing copolymers with tailor-made molecular structure in a continuous process. For instance, lateral feeds allow applying different comonomer feeding policies. Besides, manipulation of partial conversion at the lateral feeding points makes possible to control the copolymer block lengths in each reactor section.In previous works we presented a steady state model of the nitroxide mediated copolymerization in tubular reactors. This model was able to predict the sequence length distribution, average compositions, average molecular weights, monomer conversion and the MWD with respect to the total copolymer chain length, as function of the reactor axial distance. In particular, styrene (St) – α methyl styrene (AMS) and St – methyl methacrylate (MMA) copolymerizations were studied. In this work we present an extension of that model, which consists in the incorporation of the prediction of the bivariate copolymer MWD, that is, the MWD with respect to the amount of each comonomer in the chain.