Preparation and characterization of a new polylactide-b-polyimide copolymer

A new soluble polyimide was prepared by amino-terminated PEG-800 and pyromellitic dianhydride,then the amino-terminated polyimide induced ring-opening polymerization of lactide with the catalysis of stannous octanoate(Sn(Oct)2) to obtain polylactide-b-polyimide copolymer(PLA-PI-PLA).The structure of the obtained polymers was characterized by infrared spectrum(IR),1H nuclear magnetic resonance spectrum(1H NMR),gel permeation chromatography(GPC) and water contact angle.The results of FT-IR,1H NMR and GPC showed that PI and PLA-PI-PLA were successfully synthesized.Water contact angle showed that PLA-PI-PLA can improve the hydrophilicity of PLA.Meantime,the imide rings of PI could provide reactive sites to further modify the property of PLA.