Novel Grafted Copolymers Based on Poly (e-Caprolactone) and Vinylpirrolidone

G.K. Kurbanova, Z.S. Nurkeeva, P.I.Urkimbaeva, A.D. Sergaziyev

Department of Chemical Physics & Macromolecular Chemistry, Kazakh National University, Karasai Batyra 95, 480012 Almaty, Kazakhstan

Abstract

Novel water-soluble and crosslinked grafted copolymers were synthesized by g-radiation induced copolymerization of N-vinylpyrrolidone (VP) onto poly (e-caprolactone) (PCL). Results shown that the formation of soluble grafted copolymers PCL-VP is substantially affected by absorbed dose, composition of feed mixtures and concentration of solvent. It was found that the yields of grafted copolymers and grafting degree as well as grafting efficiency are increased with irradiation dose. It was established that the dependences of grafting parameters, grafting degree (G) and grafting efficiency (E), on solvent concentration are extremal curves. Moreover the reason of increase in parameters of grafting copolymerization at dilution can be explained by transition of PCL macromolecules from compact globular to unfolded conformation. Decrease in G and E values with THF content is probably attributed to the dilution effect. The swelling behaviour of PCL-VP hydrogels as a function of copolymers composition, absorbed dose, concentration of crosslinking agent and the nature of solvent was evaluated. The maximum of hydrogels swelling degree is observed in mixed solvent of some composition.