Modeling HIPS polymerization

In what follows, a batch process is considered assuming that  

In the equations given below, the PS- and PBD-rich phases are denoted with the subscripts I and II, respectively. For any generic species j, [ ] represents its molar concentration (mol L ) and Nj is the total number of moles. 

The distribution of reagents and products between the phases was obtained from the corresponding partition coefficients, Kj. These are defined on the basis of the molar concentrations. 

Neglecting the initiator contribution, and considering the solvent mass ( Gt) fh reaction masses of each phase and the total reaction mass are given by  

The weight chain-length distribution (WCLD) of the total free PS is obtained through multiplying each molecular species of the number chain-length distribution (in turn derived from the mass balance of Table 4.1) by its molar mass (mv ), yielding [30]  

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The kinetic mechanisms [35, 36] in the HIPS polymerization process and the complete process [37-41] have been mathematically modeled to a detailed level by different groups. Diverse aspects of the HIPS technology have been extensively studied in the past by many authors works that review several of these aspects are the texts of Scheirs and Priddy [42] (properties, applications, modeling, and later technologies), Echte [34] (particle morphology), Simon and Chappelear (industrial processes) [43], and Meira et al. [39] (process modeling and control). 

The influence of the molecular weight of homopolystyrene POO on the formation of polystyrene occlusions is vividly seen in fig,7, where photographs of miorostructures of HIPS specimens are represented The specimens of HIPS are obtained by the polymerization of model emulsions, prepetred by mixing solutions of rubber - 8% and polystjprene - 30% in ratio 1 1, MW PS varied at 0,7-r-3 10, As seen in fig,7 the rubber particles, formed from multiphase model emulsion as a result of redistribution of monomer, differ greatly from each other, M of polystyrene... 

Figure 7. Structure of the rubber particles in HIPS, obtained by the polymerization of model emulsions, MW of homopolystyrene in which being a) 2.9 KP X3500, b) 1.7 1(P X2500, c) 1.17 1(P XSOOO, d) 7.0 W X7000.

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