新型超支化聚酯淀粉增塑、增容剂合成及涤纶经纱用淀粉浆料应用基础

The best green textile sizing agent is starch, instead of polyvinyl alcohol which is harmful to the environment, but starch warp size has hard and brittle nature, and is lack of adhesion for chemical fibers such as polyester. The key to solve this problem is to use some plasticizers with good adhesive to polyester, also with ability to reduce sensitivity of starch film to the environment humidity. In previous studies, we found that plasticization of starch modified by polar small molecule of hyperbranched polyesters（HBPE）, such as polyglyceride citrates, can reduce crystallization-aging behavior while plastifying starch effectively. According to the concludes in references which deal with methods of improving humidity sensitivity and of increasing adhesive strength with polyester fiber, if there was a benzene ring structure in a hydrophilic HBPE similar with the polyester fiber, HBPE with designed properties may effectively plasticize the starch with abilities to reduce humidity sensitivity of the starch and to increase adhesive strength with the polyester fiber. So, based on the condensation synthesis method and structure properties of HBPE, we proposed a kind of HBPE containing benzene ring structure with certain hydrophobicity synthesized by means of molecular design. The HBPE is supposed to act as a plasticizer of starch size, a compatibilizer with polyester fiber and an age resister, The study is of great significance in clarifying the mechanism of the HBPE improving the adhesion of starch to polyester fibers and of improving the sizing performance of starch, and also in laying a foundation for research and development of high-performance plasticizing starch sizing agent.

淀粉是环保纺织浆料，是代替对环境有害的聚乙烯醇最好的选择。但是淀粉浆料具有硬脆性，对环境湿度敏感，而且对涤纶等化学纤维缺乏足够的粘附力。解决这一问题的关键是对淀粉增塑，且增加对涤纶的粘附性，并降低淀粉膜对湿度的敏感性。我们前期研究发现极性超支化聚酯（HBPE）（如柠檬酸甘油酯）可高效增塑淀粉，并抑制淀粉老化结晶。基于HBPE合成和结构特点，以及改善淀粉湿度敏感性和对涤纶粘附力的方法，设想若超支化亲水聚酯与涤纶结构部分相似，可能会兼具对淀粉增塑和降低湿度敏感，以及对涤纶粘附的综合作用。我们拟通过分子设计手段，进一步合成含苯环结构、具有一定疏水性的HBPE，探索HBPE对淀粉增塑和对淀粉与涤纶的增容作用，以及对塑性淀粉抗老化的作用，对于阐明HBPE提高淀粉对涤纶纤维的粘附力和改善淀粉上浆性能的机制具有重要意义，也能为研发高性能增塑淀粉浆料奠定基础。

淀粉是世界上产量最大的天然高分子之一，价廉、可再生、可生物降解，用途十分广泛。但是淀粉材料硬脆，力学性能不佳。除了化学和物理方法可以改善淀粉性能，外加增塑剂也是一种十分经济有效的淀粉改性方法，然而现有增塑剂并不能满足淀粉性能的所有要求。超支化聚合物具有很多特殊性能，在合成高分子增塑上也有应用，而且效果良好。本项目基于增塑和增容的需要，设计并合成了一系列超支化聚酯，用于淀粉增塑改性和涤纶纱线用淀粉浆料改性，通过淀粉中相互作用变化、淀粉结构变化，研究淀粉增塑机理。以相同的单体分别合成了不同端基、不同分子量的产物，通过差别比较，探讨增塑剂结构和性能之间的关系。甘油和柠檬酸合成的端羟基和端羧基的超支化聚酯使淀粉膜变得又强又韧，使淀粉糊液稳定性大幅提高。端羧基聚酯，由于羧基与淀粉成H键能力更强，因此使淀粉具有更好的抗老化的性能，而且其增塑淀粉膜表现出更高的断裂强度。端基的不同对淀粉糊液性能的影响差别不大，但是端羧基使淀粉糊化温度提高更明显。偏苯三酸酐和甘油合成的不同分子量的超支化聚酯的增塑结果显示，增塑剂分子量越大，增塑效应越差，但是单分子增塑效率确是提高的。不同分子量增塑剂在对淀粉抗老化性的影响差别不大，对淀粉糊化及糊液性能的影响上差异巨大。淀粉吸湿性受到超支化聚酯单体种类和性能的影响。含苯单元的超支化聚酯能明显改善淀粉浆料与涤纶纤维的相容性。因超支化聚酯合成产物结构等不可控性大以及端基可及度不足，项目后期调整方向，以多臂聚醚酯为增塑剂，进一步研究增塑剂结构与性能的关系。发现增塑效应与成H键能力大小的关系紧密，而抗老化效应则与分子大小关系更密切。分子链长短与增塑效应的大小的关系并不恒定，而是会随着增塑剂的化学结构的改变而改变。化学结构的改变也会导致增塑效应巨变。