A Mathematical Model for a Heterogeneous Bulk HIPS Process

N. CASIS, D. A. ESTENOZ, L. M. GUGLIOTTA, H. OLIVA, Y G. R. MEIRA

Santa Fe, Argentina

Congreso; ENPROMER, 3rd Mercosur Congress on Process Systems Engineering, 1st Mercosur Congress on Chemical Engineering; 2001

A mathematical model for the synthesis of high-impact polystyrene (HIPS) via the heterogeneous bulk process is presented. The model follows the polymerization in two phases: a rubber-rich one and a polystyrene-rich one. It calculates (in each phase) the evolution of the phase volume, the grafting efficiency, and the global concentrations. Each phase is considered homogeneous and a thermodynamic equilibrium between the phases is assumed. The model was validated with novel measurements. In the experimental work, a bulk polymerization of styrene in presence of polybutadiene was carried out at 70 C. From samples taken along the reaction, the monomer conversion, the grafting efficiency and the viscosity were determinated. The evolution of phase volumes as a function of conversion were also measured. A reasonable agreement between the measurements and theoretical estimates was observed.