t Preparation of Chitosan-g-Polylactic acid and the Study of its Crosslinked film

Chitosan and polylactic acid (PLLA) are biocompatible polymers with good performance. However, there are some drawbacks in chitosan and PLLA. Therefore, the as-synthesized chitosan grafted by L-lactic acid (Chitosan-g-PLLA) was prepared to improve the performance of the PLLA and chitosan. In this paper, we prepared Chitosan-g-PLLA using L- lactic acid and chitosan as reactants and Tin (II) 2-octanoate Sn(Oct)2 as catalyst. Meanwhile, the product molecular structures were characterized by FTIR and XRD. And the Thermal performance of chitosan-g-PLLA was characterized by TG-DSC, which results showed that the graft polymer began to degrade at 230 degrees C. It had excellent thermal stability. At the same time, the Chitosan-g-PLLA-PEG films were prepared by tape casting. We also studied the tensile strength, tensile strength elongation at break, etc., mechanical properties of the films. It was found that, in the same reaction conditions, PLLA-PEG couldn't be made into film, while Chitosan-g-PLLA-PEG film had good film forming, and its tensile strength elongation at break was 129%.