在微波作用下,以辛酸亚锡为催化剂,羟乙基壳聚糖(HECS)为大分子引发剂引发D,L-丙交酯(D,L-LA)开环聚合制备羟乙基壳聚糖-g-聚乳酸(HECS-g-PDLLA),通过红外(IR)、元素分析(EA)、氢核磁共振(1H-NMR)、X射线衍射(XRD)和差示扫描量热分析(DSC)对产物进行了表征。然后采用溶液共混法制备了消旋聚乳酸(PDLLA)与壳聚糖(CS)、HECS及HECS-g-PDLLA的系列复合膜,对组分间的相容性进行了研究。结果表明,在微波作用下快速合成了HECS-g-PDLLA,与HECS相比,共聚物的结晶性能下降;在CS/PDLLA复合膜中,相分离现象明显,CS在基体中的分散不均匀;HECS/PDLLA复合膜中两组分的相容性有所改善,HECS在基体中的分散较均匀,并呈现海岛状结构;而HECS-g-PDLLA/PDLLA复合膜的相容性最好,随着HECS-g-PDLLA含量的增大,两组分间相容性保持较好。
(Hydroxyethyl chitosan)-g-poly(D,L-lactide)(HECS-g-PDLLA) copolymer was synthesized by ring-opening polymerization of D,L-lactide using hydroxyethyl chitosan(HECS) as macroinitiator and stannous 2-ethylhexanoate as catalyst under microwave-assisted.The copolymer was characterized by IR,EA,1H-NMR,XRD and DSC.Then a series of blend films were prepared by solution blending with poly(D,L-lactide)(PDLLA),chitosan(CS),HECS and HECS-g-PDLLA for raw materials.The compatibility of components was studied.The results show that HECS-g-PDLLA copolymer is prepared rapidly under microwave-assisted,and its crystallinity is weaker than hydroxyethyl chitosan.SEM results indicate that phase separation is obviously existent in CS/PDLLA blend film,and the dispersion of chitosan in PDLLA matrix is heterogeneous.The compatibility of HECS/PDLLA blend film has been improved,and the dispersion of HECS is homogeneous.The compatibility of HECS-g-PDLLA/PDLLA blend films is very well,with the content of HECS-g-PDLLA increasing,the compatibility has little change.