Synthesis and properties of esterified starches with different contents of straight chain
Three types of esterified starches with different contents of straight chain were prepared by mixing formic acid with three natural starches at a certain proportion,including cassava esterified starch(EM),corn esterified starch(EN),and waxy esterified starch(EW).The structural properties of the as-prepared esterified starches were character-ized and analyzed using Fourier-transform infrared spectroscopy,wide-angle X-ray diffraction,scanning electron micros-copy,and thermogravimetric analysis.The changes in the mechanical properties of PBS/esterified starch blends were further analyzed.The result indicated that the starches exhibited a hydrophobic property after esterification,and their hy-drophobic degree increased with an increase in the amylose content.The crystal structure of the starches was damaged by the incorporation of the esterified starch.The crystalline degree of the starches was proportional to the content of amy-lose,and their heat loss rate increased proportionally with an increase in the amylopectin by a factor of EM(237℃)>EN(235℃)>EW(231℃).The hydrogen bond interaction between the molecules of the starches decreased,result-ing in an improvement in the thermoplasticity of the starches.Moreover,the esterified starch with a high content of amy-lopectin has a good plasticizing effect.
国家科技期刊平台
NSTL
万方数据
维普
