聚乳酸-壳聚糖接枝共聚物的制备及性能

The Synthesis and Properties of Poly(L-Lactide)-Chitosan Graft Copolymer

以L-乳酸(LLA)和壳聚糖(CS)为原料,4-(二甲胺基)吡啶(DMAP)及N,N′-二环己基碳酰亚胺(DCC)为催化剂在室温下,通过直接缩合方法制备了聚乳酸-壳聚糖接枝共聚物(PLLA-CS)。采用IR、1H-NMR及薄板毛细渗透法对其结构进行了表征。探讨了原料配比、催化剂用量、LLA的二氯甲烷溶液浓度、反应时间等对共聚物收率和亲水性的影响。得到最佳工艺条件:-NH2∶LLA为1∶15,DCC∶LLA为1∶1,LLA的二氯甲烷溶液浓度为1.88 mol/L,反应时间为24 h。此方法合成路线短、反应条件温和。聚乳酸-壳聚糖接枝共聚物具有良好的细胞亲和性,有望成为一类优良的组织工程材料。

Graft copolymerization of L-lactide（LLA） onto chitosan（CS） was carried out by the direct polycondensation using 4-（dimethylamino） pyridine（DMAP） and N,N′-dicyclohexylcarboniimide（DCC） as catalyst in dichloromethane at room temperature to obtain poly（L-lactide）-chitosan（PLLA-CS） graft copolymers.The graft copolymers were characterized by IR,1H-NMR and thin-layer wicking technique.Grafting studies indicate that the ratio of raw materials（-NH2∶LLA）,the amount of catalyst,the concentration of LLA and the reaction time influence the yield and contact angle of the copolymer.The optimum reaction conditions are as follows： the ratio of-NH2 to LLA 1∶15,the ratio of DCC to LLA 1∶1,the concentration of LLA 1.88 mol/L and reaction time 24 h.On the conditions,the yield of PLLA-CS copolymer is high and the contact angle is small.The grafting of LLA onto CS resulted in graft copolymers having increases the hydrophilicity.The results prove that the synthesis process has short route,simple technology,and mild conditions.