The three-dimensional polycondensation of bifunctional hexamethylene diamine and trifunctional guanidine hydrochloride is studied. It is shown that the properties of this process do not follow the classical Flory theory. One of the most interesting features is the dependence of the critical extent of the polycondensation (i.e. the gel point) on the synthesis temperature. It is supposed that the reason for this is the different reactivity of the functional groups of guanidine hydrochloride and the different temperature coefficient of reactivity. As a result, some parts of the functional groups are excluded from the reaction. It is supposed that the reason for this is the ionomer character of the guanidinium links in the linear chains. Due to dipole~lipole interactions the ion pairs associated with the third functionality of these links aggregate into multiplets. Thus, reaction groups turn out to be effectively sterically screened and their ability to enter into the reaction with the formation of branching points becomes restricted.
Посилання на статтю:
Three-dimensional polycondensation of monomers with ionomer-type interactions / Alexei R. Khokhlov*, Saga-Silvia A. Pavlova, Galina I. Timofeeva,Ekaterina V. Stoljarova and Larisa U. Bazaron // Polymer. – 1994. – Vol 35. – P. 1769-1773.