以壬烯基琥珀酸酐为酯化剂，4-二甲氨基吡啶（DMAP）为催化剂，离子液体（1-乙基-3-甲基咪唑氯盐）水溶液为溶剂制备酯化淀粉。将酯化淀粉与聚乳酸（PLA）共混制备复合材料。采用傅里叶变换红外光谱仪（FTIR）、扫描电子显微镜（SEM）、接触角测量仪对酯化淀粉及其PLA复合材料的结构和性能进行测试表征。结果表明：制备酯化淀粉的较佳工艺是反应时间为2.5 h，反应温度为85 ℃，催化剂用量为淀粉的2%，n（离子液体）∶n（水）为1∶10，n（酯化剂）∶n［淀粉中脱水葡萄糖单元（AUG）］为1∶3。在最佳反应条件下，取代度为0.92 mmol/g。FTIR分析表明：淀粉已经被成功酯化。接触角测试表明：酯化淀粉的亲水性降低，与PLA的接触角相似。DMA结果表明：酯化改性提高了淀粉与PLA的相容性。力学性能测试结果表明，当酯化淀粉质量分数为25%时，复合材料的拉伸强度、弯曲强度和冲击强度比PLA/原淀粉复合材料分别提高4.7%、132%和26.5%。SEM表明，酯化后的淀粉表面形貌发生变化，酯化后淀粉与PLA相容性得到改善。

Esterified starch was prepared by nonenyl succinic anhydride as esterification agent, 4-dimethylaminopyridine (DMAP) as catalyst, and ionic liquid (1-ethyl-3-methylimidazole chloride) aqueous solution as solvent. Esterified starch and polylactic acid (PLA) were mixed to prepare composites. The structure and properties of esterified starch and its PLA composites were characterized by a Fourier transform infrared spectrometer (FTIR), a scanning electron microscope (SEM), and a contact angle goniometer. The results indicated that the optimal process for preparing esterified starch was reaction time of 2.5 h, reaction temperature of 85 ℃, catalyst dosage of 2% of starch, n(ionic liquid)∶n(water) of 1∶10, and n(esterification agent)∶n[dehydrated glucose unit (AUG) in starch] of 1∶3. Under the optimal reaction conditions, the degree of substitution was 0.92 mmol/g. FTIR analysis indicatesd that the starch has been successfully esterified. The contact angle test showed that the hydrophilicity of esterified starch decreased, similar to the contact angle of PLA. The DMA results showed that esterification modification improved the compatibility between starch and PLA. The mechanical property test results showed that when the mass fraction of esterified starch was 25%, the tensile strength, bending strength, and impact strength of the composites were increased by 4.7%, 132% and 26.5% compared to the PLA/ original starch composites, respectively. SEM results showed that the surface morphology of the esterified starch changed, and the compatibility between the esterified starch and PLA was improved.