摘要
通过改变柠檬酸用量、反应时间及反应温度制得了不同特性黏度的低分子量淀粉;FTIR表明淀粉分子量降低到一定程度后,分子链聚集,分子链密度增加,特征基团数量增加,同时分子链上没有酯基的出现;高用量甘油增塑淀粉后,热塑性低分子量淀粉(TPLS)的熔体指数MI明显低于热塑性天然淀粉(TPNS),毛细管流变仪和橡胶加工分析仪(RPA)测试进一步表明,在低剪切时热塑性淀粉(TPS)的流动黏度随着分子量的减小反而增大,由此证明低分子量淀粉的塑化性较差,分子间作用力在低剪切时起重要的作用;TPLS的拉伸强度和弹性模量均高于TPNS,而断裂伸长率随着分子量的减小而逐渐变小,通过机理的分析说明了低分子量淀粉较强的分子间作用力是造成其特殊流变性征的主要原因。
The low molecular weight starch with different intrinsic viscosity was prepared, according to change the reaction terms,the content of citric acid,react time and temperature. FTIR indicated that molecular chains cluster, the density of molecular chains and number of characteristic groups increased, and no ester groups appeared as well when the molecular weight of starch degraded to a certain degree. After plasticized by high-content glycerol, the MI of thermoplastic starch with low molecular weight （TPLS） was sharply lower than the thermoplastic native starch （ TPNS ） , the test of rheologie property by capillary rheometer and rubber process analyzer（RPA） future illustrated that the flow viscosity of thermoplastic starch（TPS） improved though the molecular weight decreased at lower shear, and which approved that the plasticization of low molecular weight starch was weak,the intermolecular interaction had a more important effect on the rheological properties of TPS at lower shear. Both the tensile strengthen and elastic moduli of TPLS were higher than TPNS while the strain at break was gradually reducing with the decreasing molecular weight. According to the mechanics analyze, the special rheologic property of low molecular weight starch mainly resulted from its strong intermolecular interaction.
出处
《塑料》
CAS
CSCD
北大核心
2008年第2期19-24,共6页
Plastics
关键词
低分子量淀粉
熔体指数
流变性能
RPA
low molecular weight starch
melt flow index
rheologic prosperity
RPA
