中文摘要：

以氯仿为共溶剂,通过溶液共混,制备了不同组成的N,N-双十二烷基化壳聚糖/聚（L-乳酸）（NCS/PLLA）复合膜.利用红外光谱、热分析、WAXD及SEM探讨了复合膜的氢键作用和相容性.红外分析表明,NCS随PLLA的加入,NCS的缔合羟基伸缩振动由3430cm^-1红移至3 380 cm^-1、谱带变宽、吸收增强;随NCS的加入,PLLA的羰基伸缩振动由1 760 cm^-1红移到1 753 cm^-1.热重及热重微分分析表明,复合膜的热稳定性高于纯NCS;DSC分析表明,NCS的加入使PLLA的Tm降低,结晶度下降.WAXD分析表明,NCS的加入使PLLA在2θ=16.7°和2θ=19.1°的结晶衍射峰往低角度偏移、峰变宽、峰强逐渐减弱,当NCS为50%和75%时,PLLA的结晶衍射峰消失.SEM观察表明NCS/PLLA复合膜无相分离.实验结果表明NCS与PLLA存在较强的氢键作用,复合膜具有良好的相容性.

英文摘要：

N,N- dilauryl chitosan/PLLA （NCS/PLLA） blend membranes with three different compositions were prepared by solution approach using CHCl3 as cosolvent. The hydrogen-bonding interactions between NCS and PLLA were studied with FTIR, TA and WAXD methods. FTIR experiments indicated that the wave numbers of hydroxide stretching band of NCS and the carbonyl stretching band of PLLA in the blend membranes had a red-shift change compared with both pure materials. TA results confirmed that the thermal stability of the blend membranes was higher than that of NCS alone, the Tm and crystallinity of PLLA in blend membranes decreased compared with pure PLLA. WAXD patterns showed that the crystal peaks of PLLA at 20= 16.7°, 19.1° shifted to a lower angle, and the diffraction peak beca me weaker and broader obviously in the blend membranes with increasing NCS content, even disappeared when NCS content reached 50%. SEM images of blend membranes showed that good miscibility existed in this blend systems. The most interesting and important finding of the present study was that the miscibility of the NCS/PLLA blend systems mainly came from hydrogen-bonding interactions between the hydroxyl groups of NCS and the carbonyl groups of PLLA.