淀粉粒度对热塑性淀粉性能的影响研究

Effect of particle size of starch on the properties of thermoplastic starch

摘要: 研究了微细化淀粉结晶度的变化以及淀粉粒度对热塑性淀粉性能的影响，结果表明，淀粉粒度降低的同时，其颗粒团聚作用明显。机械研磨作用能够明显地破坏淀粉分子的结晶结构，导致其结晶度降低，而无序化程度增加。淀粉粒度的适度降低对热塑性淀粉性能有显著改善作用，以中位径d₅₀≈4.23 μm附近的微细化淀粉为原料制备热塑性淀粉，其力学性能，熔体流变性以及生物降解性均较为理想，抗拉强度为21.7 MPa，断裂伸长率为138.3%，28 d土埋生物降解失重率近60%。

Abstract: The crystallinity of micronized starch and the effect of particle size of starch on the properties of thermoplastic starch were studied. It was found that the starch was destroyed by mechanical treatment. However, starch particles join more easily as the size of starch decreases. It was found that when the particle size of starch was suitable, the properties of thermoplastic starch were improved. The thermoplastic starch was prepared by micronized starch of d₅₀=4.23 μm. Its mechanical property, rheological property and degradation were excellent. Its tensile strength was 21.7 MPa, and the breaking elongation was 138.3%. It was also concluded that its biodegradation ratio was close to 60% in the soil after 28 days.