Novel graft copolymers with aliphatic polyether and polyester main chains. (19th November 2015) - Zhang, Haiping
Abstract: A series of new graft copolymers was synthesized by a "grafting to" approach, in the course of which the polymer backbone was build up first by a chain extension reaction of polyether or polycaprolactone diols with bis-N-acyl lactams. During the first reaction step, benzoxazinone groups were introduced into the backbone which served as grafting sites for monoamino-terminated polyamide 12 or polystyrene. Chain extension and grafting could be performed successively and with high selectivity in the melt at 180–220 °C. The morphology and the thermo-mechanical behavior of the graft copolymers were strongly influenced by the type of the grafted side chains. Polymers with polyamide grafts exhibited a two phase morphology with a spherulitic superstructure in the micrometer scale. The tensile behavior of these polymers was characterized by a certain elastic component. In contrast, the phase morphology of a polystyrene grafted polymer was much finer. A strong influence on the glass transitions revealed improved compatibility between the components. Pronounced strain hardening was observed during the tensile test of polystyrene grafted samples. Graphical abstract: Highlights: New agents for selective coupling of amino and hydroxyl groups were utilized. Graft copolymers with a PTHF backbone and PA12 or PS grafts were synthesized. The polymer synthesis was carried out in two steps in the melt. Graft copolymers with PA12 grafts exhibited a typical spherulitic superstructure. The graft copolymers showed pronounced elastic behavior.