中文摘要：

以烯基琥珀酸酐（ASA）作为新型增塑剂，使用三氯甲烷作为聚乳酸（PLA）和乙基纤维素（EC）的共溶剂，采用溶液浇铸法成功制备了聚乳酸／乙基纤维素复合膜。用红外光谱（FTIR）、X射线衍射（XRD）表征了复合膜结构，并测试了其吸水性和力学性能。FTIR测试结果显示，复合膜中存在强烈的氢键相互作用。XRD表明，ASA显著提高了PLA和EC2种高聚物的界面黏合性。力学测试结果表明，ASA对该复合膜具有良好的增塑效果。当膜中PLA质量分数≤37％时，PLA对复合膜起增强作用。复合膜的吸水性随ASA含量的增大而降低，随PLA含量的增大而提高。该复合膜作为一种潜在的药物缓释材料，将具有广阔应用前景。

英文摘要：

The poly（lactic acid）/ethyl cellulose composite films were prepared by a casting method using n-alkenyl succinic anhydride（ASA） as novel plasticizer and chloroform as co-solvent. Fourier transform infrared spectroscopy （FTIR） and X-ray diffraction （XRD） were used to analyze the morphological properties of the composite films. The mechanical properties and water absorption of the cast composite films were also measured. FTIR indicates that there are some strong interaction and good compatibility in the composite films. XRD shows that both poly（lactic acid） （PLA） and ethyl cellulose（EC） lose crystallinity after being plasticized, and the PLA/EC composite films plasticized with n-ASA result in a markedly enhanced coalescence of the two polymers. The mechanical properties were tested and n-ASA becomes an ideal plasticizer for EC based films. The PLA resin has a reinforcing effect on PLA/EC composite films when the mass fraction of PLA is less than 37%. The water absorption decreases with increasing ASA content while it increases with increasing PLA content in the PLA/EC composite films. The composite films can be used as a new kind of drug delivery material with a wide application prospect.