Key Laboratory of Bio-based Material Science and Technology (Ministry of Education), Northeast Forestry University, Harbin, 150040, PR China.
Key Laboratory of Bio-based Material Science and Technology (Ministry of Education), Northeast Forestry University, Harbin, 150040, PR China.
Int J Biol Macromol. 2014 Mar;64:174-80. doi: 10.1016/j.ijbiomac.2013.11.026. Epub 2013 Dec 4.
Corn starch and maleic anhydride were synthesized from a maleic anhydride esterified starch by dry method. Fourier transform infrared spectroscopy (FTIR) was used for the qualitative analysis of the esterified starches. The reaction efficiency of dry method esterified starch reached 92.34%. The dry method esterified starch was blended with polylactic acid (PLA), and the mixture was melted and extruded to produce the esterified starch/polylactic acid (ES/PLA) composites. The degree of crystallinity of the ES/PLA was lower than that of the NS/PLA, indicating that the relative dependence between these two components of starch and polylactic acid was enhanced. Scanning electron microscopy (SEM) indicated that the dry method esterified starch increased the two-phase interface compatibility of the composites, thereby improving the tensile strength, bending strength, and elongation at break of the ES/PLA composite. The introduction of a hydrophobic ester bond and increase in interface compatibility led to an increase in ES/PLA water resistance. Melt index determination results showed that starch esterification modification had improved the melt flow properties of starch/PLA composite material. Strain scanning also showed that the compatibility of ES/PLA was increased. While frequency scanning showed that the storage modulus and complex viscosity of ES/PLA was less than that of NS/PLA.
采用干法将马来酸酐酯化淀粉制备成淀粉接枝马来酸酐，利用傅里叶变换红外光谱（FTIR）对酯化淀粉进行定性分析。干法酯化淀粉的反应效率达到 92.34%。干法酯化淀粉与聚乳酸（PLA）共混，熔融挤出制备淀粉接枝马来酸酐/聚乳酸（ES/PLA）复合材料。ES/PLA 的结晶度低于 NS/PLA，说明淀粉和聚乳酸两种组分的相对依赖性增强。扫描电子显微镜（SEM）表明，干法酯化淀粉增加了复合材料的两相间界面相容性，从而提高了 ES/PLA 复合材料的拉伸强度、弯曲强度和断裂伸长率。引入疏水性酯键和增加界面相容性，导致 ES/PLA 的耐水性提高。熔体流动指数测定结果表明，淀粉酯化改性提高了淀粉/PLA 复合材料的熔体流动性能。应变扫描也表明 ES/PLA 的相容性增加。而频率扫描表明 ES/PLA 的储能模量和复数黏度均小于 NS/PLA。
