pH值对聚乳酸纤维结构及力学性能的影响

针对酸碱环境对聚乳酸纤维使用性能的影响,利用红外光谱、X衍射及激光显微镜分别对不同pH值处理聚乳酸纤维的大分子结构、聚集态结构以及形态结构进行分析,并借助纤维强力仪探讨了pH值对聚乳酸纤维物理性质的影响。结果表明:pH值太高或太低,聚乳酸纤维内部酯基水解反应剧烈,纤维表层粗糙;pH值太高或太低,聚乳酸纤维的断裂强度、屈服强度、断裂伸长率与初始模量下降趋势越显著。因此,聚乳酸纤维在加工、整理、改性及使用过程中应依据要求合理控制环境中pH值的范围。

Effect of pH value on structural and mechanical properties of PLA fiber

In this paper,the effects of acid-base environment on the performance of PLA fibers were studied.The macromolecular structure,aggregate structure,morphological structure and mechanical properties of poly lactic acid fiber which treated with different pH solutions were investigated by Infrared spectrometer,X-ray diffractometer,Laser microscope and the single fiber strength tester.The results showed that the roughness and ester base hydrolysis reaction of poly lactic acid fiber were improved,and the values of breaking strength,yield strength,initial modulus and elongation at break of poly lactic acid fiber were reduced significantly,when the pH value was high or low.Therefore,pH value of the environment should be reasonably controlled according to the requirements during the process of processing,finishing,modification and use of PLA fibers.