二甲基亚砜/水溶液体系中氢键对静电纺淀粉纤维的影响

Influence of hydrogen bonding on electrospinning of starch nanofiber in dimethyl sulfoxide/H_2O solution

为探究氢键对静电纺淀粉纤维膜的影响,以二甲基亚砜/水为溶剂体系对淀粉进行溶解制备静电纺纤维膜。通过调节二甲基亚砜/水体系中含水量,诱导水分子与淀粉分子链上的羟基结合形成氢键,研究氢键对淀粉溶解及淀粉纤维成型的影响。通过扫描电子显微镜、红外光谱、差热分析、X射线衍射及拉伸实验等对静电纺淀粉纤维的表面形貌、结构和力学性能进行表征。结果表明:二甲基亚砜破坏了淀粉分子中的氢键,有利于淀粉的溶解;随着二甲基亚砜/水体系中含水量的增加,水与淀粉分子链中的羟基形成了氢键。氢键的形成会对淀粉纤维产生影响,一方面,氢键的形成使得淀粉纺丝液的可纺性变差,纤维形貌变得不均一;另一方面,对于静电纺纤维膜而言,过多的水会与淀粉分子形成氢键,抑制分子链的自由移动,导致纤维膜的断裂强度提高,断裂伸长率下降。

In order to investigate the influence of hydrogen bonding on the starch nanofiber,starch nanofibers were prepared by electrospinning using dimethyl sulfoxide（DMSO）/H2 O solution system. The influence of hydrogen bonding on starch dissolution and starch fiber formation were studied. The surface morphology and structure of electrospun starch fiber were characterized by scanning electron microscopy,infrared spectroscopy,differential thermal analysis,X-ray diffraction and tensile test. The results show that DMSO destroyes hydrogen bonds in starch molecules,which facilitates the dissolution of starch. With the increase of the water content in the solution system,hydrogen bonds will be formed between water and hydroxyl groups on the starch chain. On one hand,the formation of hydrogen-bonding network structure in the solution system results in poor spinnability starch solution. On the other hand,for the electrospunfiber membrane,hydrogen bonds will be formed between water and the starch molecules,which will inhibit the free movement of molecular chains of the nanofibers. This will result in increasing of the breaking strength and decreasing of the breaking elongation of the starch nanofibers.