Impact of wet processing on structure and properties of PLA fiber

Using the X-Ray Diffractomer and Electron Scaning Microscope,the changes in structure and tensile properties of PLA fiber during wet-hot processing have been investigated.The results show that the wet-hot processing have obvious impact on the structure and properties of PLA fiber.Increasing the temperature, the weight loss and damage degree of tensile strength of PLA fiber are increased,as well as the increase of its crystallinity.The pH value of solution has great effect on the strength property of PLA fiber.Both acid and alkali will catalyze the hydrolysis of PLA fiber and increase the loss of strength.In contrast, the alkali has more impact.In weak alkaline solution,the hydrolysis of fiber occurrs from the surface to inner so that the fiber becomes obviously fine.Some pits are observed on surface of fiber because of different hydrolysis rates.