Designed, Synthesis, And Characterization Of Chitosan-Graft-Polyester

It is promising to combine the bioactive functions of chitosan with the good mechanical properties of polylactides (PLA) orpoly(ε-caprolactone) (PCL) to generate a new biohybrid material, which should be applicable for drug delivery systems and tissue engineering. Chitosan-graft-poly(ε-caprolactone) (chitosan-g-PCL) was prepared via ring-opening graft polymerization ofε-caprolactone (CL) through chitosan using 4-dimethylaminopyridine (DMAP) as a catalyst and water as a swelling agent. The graft content of PCL within the graft copolymer can be adjusted by the feed ratio of CL to chitosan, and the highest grafting content of PCL was up to about 400 %. The analyses of FT-IR, ¹H NMR, and two-dimensional heteronuclear single quantum coherence (HSQC) indicated that it was the amino group (NH₂-CH-2) of chitosan that initiated the graft polymerization of CL through the backbone of chitosan, and the hydroxyl group (HO-CH₂-6) of chitosan did not participate in initiating the graft polymerization. The amino group percent initiating the graft polymerization decreased with the increasing molar ratio of CL to chitosan in feed, which is attributed to that the graft...