The polymerization of diepoxide-diamine is simulated using a two-stage procedure. In the first stage a convenient epoxy or amine excess is used to prepare a liquid prepolymer at complete conversion, which is then cured in a second step by balancing stoichiometry. The possibility of a secondary addition of the excess monomer is also considered. The extent of reaction leading to gelation in the second stage is obtained analytically for ideal systems and numerically when substitution effects in the amine hydrogens are taken into account. By selection of an appropriate initial stoichiometry, the gel conversion in the second stage may be considerably reduced when compared to the typical one-stage stoichiometric system (pBe~=0.6). This may have practical applications for reducing residence times in heated moulds or to freeze a phase separation process produced in the first stage of the polymerization.
Посилання на статтю:
Influence of prepolymerization on gelation of diepoxide-diamine systems / Carmen C. Riccardi and Roberto J. J. Williams* // Polymer. – 1992. – Vol 33. – P. 44-51.