GRAFT COPOLYMERS BY OXONIUM POLYMERIZATION .5. GRAFTING POLYTETRAHYDROFURAN FROM POLYMERIC TRIFLATE ESTERS

In the course of our continuing fundamental investigations on grafting by oxonium polymerization, the authors discovered an efficient synthesis for the preparation of polytetrahydrofuran (PTHF) graft copolymers. The synthesis is based on the well known fact that triflate esters will initiate the polymerization of tetrahydrofuran (THF). The essence of the discovery is that macromolecular triflate esters readily initiate the polymerization of THF, and that suitable triflates can be readily produced in situ by contacting polymers containing active halogens with silver triflate. In the reported experiments, the preparation of poly(vinyl chloride)-g-polytetrahydrofuran (PVC-g-PTHF) was used as an example to illustrate the efficacy and simplicity of this synthesis. The reactions were carried out at room temperature in a nitrogen atmosphere. IR spectra of PVC-g-PTHF are presented and analyzed. It is demonstrated that soluble graft copolymers from PVC and PTHF can be synthesized by adding AgOSO//2CF//3 to a solution of PVC in THF and that the graft is essentially free of both homoPTHF and unreacted PVC.