Key Laboratory of Science and Technology of Eco-Textile, Ministry of Education, Jiangnan University, 1800 Lihu Ave., Wuxi 214122, Jiangsu, China.
Key Laboratory of Science and Technology of Eco-Textile, Ministry of Education, Jiangnan University, 1800 Lihu Ave., Wuxi 214122, Jiangsu, China; Myande Group Co., Ltd., 199 South Ji'An Road, Yangzhou 225127, Jiangsu, China.
Carbohydr Polym. 2020 Apr 15;234:115910. doi: 10.1016/j.carbpol.2020.115910. Epub 2020 Jan 23.
It is well known that mixing pullulan (PUL) with starch can overcome the poor physical properties of pure starch based film. However, the mechanism of improvement of physical properties of starch film with PUL is yet to be clearly understood. The objective of this study is to investigate the effect of PUL in potato starch (PS) condensed matter solution and illustrate the mechanism improvement of physical properties of PS film by mixing with PUL. The moisture content of PS-PUL film decreased by 18.61 % because PS-PUL film chain-structure was denser than that of PS film. Based on the analysis of condensed matter solution, PUL could reduce the speed of PS chain movement and increase the flexibility of PS rigidity chains. Thus, tensile strength of PS-PUL film decreased by 20.34 % and elongation at break of PS-PUL film increased by 23.45 %. An increase in bending endurance by 49.51 % also illustrates that PUL improved the chain flexibility in the process of composite film formation. The present research provides a novel research route to understand the mechanism of hydrophilic colloids affecting the physical properties of starch film at molecular level. Also, the work provides a theoretical basis for the establishment of a correlation system between the microstructure and macroscopic properties.
众所周知，将支链淀粉（PUL）与淀粉混合可以克服纯淀粉基薄膜的物理性能差的问题。然而，用 PUL 改善淀粉薄膜物理性能的机制尚不清楚。本研究的目的是研究 PUL 在马铃薯淀粉（PS）凝聚态溶液中的作用，并通过与 PUL 混合来阐明改善 PS 薄膜物理性能的机制。PS-PUL 薄膜的水分含量降低了 18.61%，因为 PS-PUL 薄膜链结构比 PS 薄膜更致密。基于凝聚态溶液的分析，PUL 可以降低 PS 链的运动速度，增加 PS 刚性链的柔韧性。因此，PS-PUL 薄膜的拉伸强度降低了 20.34%，断裂伸长率增加了 23.45%。弯曲强度提高了 49.51%，这也表明 PUL 提高了复合膜形成过程中链的柔韧性。本研究为从分子水平理解亲水性胶体影响淀粉薄膜物理性能的机制提供了一条新的研究途径。此外，该工作为建立微观结构与宏观性能之间的相关体系提供了理论依据。
