Synthesis and characterization of poly(-caprolactone-co-ethylene glycol) star-type amphiphilic copolymers by "click" chemistry and ring-opening polymerization

The synthesis of poly(-caprolactone-co-ethylene glycol) AAB star-type amphiphilic copolymers were carried out by use of a click chemistry reaction to block propargyl polyethylene glycol (propargyl-PEG) to terminally azide poly(-caprolactone) (PCL-N-3). For this purpose, propargyl-PEG was synthesized by the reaction of PEGs (3000Da, 2000Da, 1500Da, and 1000Da) and propargyl chloride. Terminally chloride poly(-caprolactone) (PCL-Cl) was carried out by means of ring-opening polymerization (ROP) of -caprolactone (CL) and 3-chloro-1,2-propanediol. Synthesis of PCL-N-3 was obtained by the chemical interaction of PCL-Cl and sodium azide. By reacting propargyl-PEG and PCL-N-3, the star-type amphiphilic copolymers were obtained. The characterization of products was accomplished by using multiple instruments including H-1-NMR, FT-IR, GPC, TGA, contact angles, and elemental analysis techniques.