结晶行为对热塑性淀粉材料性能的影响

Effect of Crystallization. Behavior on Properties of Thermoplastic Starch

分析研究了几种淀粉和热塑性淀粉的结晶性能、流变性能、力学性能以及含水量对热塑性淀粉的重结品性能以及对材料的影响。结果表明：虽然几种淀粉的结晶度不同，结晶类型不同，但淀粉的塑化性能、拉伸强度、断裂伸长率与结晶度、结晶类型无关，只与淀粉分子中直链分子链的含量有关、与淀粉的相对分子质量有关。实验结果还表明：热塑性淀粉在放置时间内会出现重结晶现象，结晶的晶型有所转变；结晶度呈现增大趋势，其变化速度与热塑性淀粉中水含量有关，水可以促进热塑性淀粉的重结晶，甘油可以减小重结晶速度。

The crystallization, rhcological, and mechanical behaviors of a series of starch were investigated. It indicated that the rheological and mechanical properties of the starch were not dependent on the degree of crystallinity and crystal form, but on the molecular weight and the content of the straightchain. Recrystallization was observed during the standing period, which resulted in the change of the crystal form and the decline of the mechanical properties. Moisture would promote, and glycerol would depress the rate of recrystallization.