BRANCHING-PROCESS OF THE GRAFTING REACTION BETWEEN 2 REACTIVE POLYMERS

Graft coupling between two reactive polymers can lead to the formation of compatibilized blends. There is a need to control the extent of gr aft coupling if the grafting system is capable of gelation, not just f or the control of phase size and morphology, which depend on the amoun t and structures of graft copolymers in a ternary blend. In this paper , we give a thorough analysis of the molecular characteristics of the grafting system of two reactive polymers each having a large number of reactive groups. A kinetic approach is employed to quantify the molec ular characteristics: concentration of individual species, molecular-w eight averages and gel point. It is found that the percentage conversi ons of the reactive polymers to copolymers are quite limited in order to avoid a weight-average molecular weight of the system that is too h igh. The presence of a high-molecular-weight tail in the polydisperse reactive polymers further limits the extent of the grafting reaction, an undesirable factor in such a grafting system.