Synthesis of dextran-graft-PHBHV amphiphilic copolymer using click chemistry approach

Abstract

Dextran-graft-PHBHV copolymers were prepared using click-chemistry. Well defined and functional dextran backbones containing azide groups had been prepared by tosylation and subsequent nucleophilic displacement reaction with sodium azide (DSN3=1). Well defined PHBHV oligomers containing an alkyne end group were prepared in a one step reaction by direct alcoholysis from natural polyesters using propargyl alcohol with dibutyltin dilaurate as catalyst. Oligoesters were obtained with molar masses ranging from 900 to 6200gmol−1. The Huisgen 1,3-dipolar cycloaddition allowed the preparation of graft copolymers with a content of PHBHV up to DSPHBHV=0.19. The presence of PHBHV on the dextran backbone led to the formation of stable nanoparticles (160nm) without surfactant by an emulsion–solvent evaporation method.