A mathematical model of hetero-phase polycondensation processes

• Published in: Polymer science USSR 1973, Vol.15 (5), p.1102-1108
• Main Authors: Sharikov, Yu.V., Fedotova, M.I., Sokolov, L.B.
• Format: Article
• Language: English
• ISSN: 0032-3950; 1878-268X
• DOI: 10.1016/0032-3950(73)90369-9

Polycondensation in heterogeneous systems (hetero-phase polycondensation) is now used extensively for synthesis of new polymers and the method is of industrial value in some instances. The extensive use of hetero-phase polycondensation can be attributed to certain specific features of this method that clearly distinguish it from other methods of polycondensation. These include the possibility of obtaining polymers of high molecular weight from monomers present in non-equimolar ratios and (in the interfacial variant) under any hydrodynamic regime, the possibility of obtaining high-polymers in almost any solvent, the lesser importance of the purity of the monomers etc. Among the many forms of hetero-phase polycondensation the interfacial and emulsion variants can be clearly distinguished [1]. In emulsion polycondensation polymer formation occurs entirely within one of the phases (usually in the disperse (organic) phase) and the reaction is kinetically controlled. In interfacial polycondensation the reaction is localized at the interfacial boundary. These variants are obviously the two extreme cases of hetero-phase polycondensation. Intermediate cases can arise, in which the reaction zone occupies part of the bulk of the reaction phase (from a narrow region close to the boundary up to the entire volume). The region in which the reaction occurs will depend on the adsorptive capacity of the surface layer, the ratio of the diffusing monomer currents and on the rate of the main reaction. Experimental study of the effect of these factors on the process of polymer formation involves considerable difficulty. Moreover it is not always possible to isolate the effect of the parameter in which one is interested, without uncontrolled variation in other factors.