State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
Carbohydr Polym. 2015;127:79-85. doi: 10.1016/j.carbpol.2015.03.022. Epub 2015 Mar 20.
Native corn starch was esterified with acetic anhydride and plasticized with glycerol to give the thermoplastic starch acetate (TPSA). TPSA was blended with polylactide (PLA) and polyether-block-amide-graft-glycidyl methacrylate (PEBA-g-GMA) to obtain biodegradable PLA/PEBA-g-GMA/TPSA blends with high notched impact resistance and low cost. Compared with PLA/PEBA-g-GMA blends, as much as 9 wt% expensive PEBA-g-GMA elastomer could be substituted by the slightly acetylated thermoplastic starch while retaining high impact strength. The mechanical properties depended on the esterification degree of starch acetate. The impact strength, tensile strength and elongation at break increased to the peak value with increasing the esterification degree from 0 to 0.04, thereafter they decreased on further increasing the esterification degree. The morphological results showed that the TPSA particles were smaller and more uniform at the optimum esterification degree of 0.04, leading to the peak value of the mechanical properties.
天然玉米淀粉用乙酸酐进行酯化，并用甘油进行增塑，得到热塑性淀粉醋酸酯（TPSA）。TPSA 与聚乳酸（PLA）和聚醚嵌段酰胺接枝甲基丙烯酸缩水甘油酯（PEBA-g-GMA）共混，得到具有高缺口冲击强度和低成本的可生物降解 PLA/PEBA-g-GMA/TPSA 共混物。与 PLA/PEBA-g-GMA 共混物相比，通过稍微乙酰化的热塑性淀粉，可以替代高达 9wt%昂贵的 PEBA-g-GMA 弹性体，同时保持高冲击强度。机械性能取决于淀粉醋酸酯的酯化度。随着酯化度从 0 增加到 0.04，冲击强度、拉伸强度和断裂伸长率增加到峰值，然后进一步增加酯化度时它们会降低。形态结果表明，在最佳酯化度为 0.04 时，TPSA 颗粒更小且更均匀，导致机械性能达到峰值。
