玉米淀粉醋酸酯的制备及成膜性能

Preparation and Characterization of Corn Starch Acetates and Its Film Properties

以冰醋酸和醋酸酐为改性剂,浓硫酸作催化剂,合成了玉米淀粉醋酸酯,用傅立叶红外(FT-IR)、扫描电镜(SEM)、差示扫描量热法(DSC)、X射线衍射(XRD)分别对淀粉醋酸酯的结构、形貌、玻璃化转变温度和结晶度等进行测试和表征,分析了不同酯化度对淀粉的微观结构和热性能的影响。结果表明,淀粉经酯化后,结晶度降低,热性能提高,制备的酯化淀粉/聚乙烯醇的复合膜具有较好的力学性能和疏水性。

Starch acetates （SA） with different degree of esterification were synthesized by corn starch reacting with acetic acid/acetic anhydride, using sulfuric acid as catalyst. By Fourier transform infrared spectrogram （FT-IR）, scanning electron microscopy （SEM）, differential scanning calorimetry （DSC） and X-ray diffraction, we studied the microstructure, particle shape, glass transition temperature and crystallization degree, comparing with those of native starch to get knowledge about influences of different degree of substitute on microstructure and thermal property of starch acetates. The results show crystal degree of starch acetates decreases and thermal property increases. At the same time, SA/polyvinyl alcohol （PVA）, biodegradable material, was gained by crossing, and the mechanical and hydrophobic properties of this material were better than those of native starch/PVA.