Original Silk Pre-Oxidation Treatment of Carbon Fiber from Coal Tar Pitch

Abstract

In the preparing process of carbon fiber, the fiber mechanical performance is affected by the pre-oxidation condition. In this paper the pre-oxidation technology condition of the original silk is researched, and the functional group in the molecule and the process of thermal gravimetric of the original silk and pre-oxidized silk are investigated by the method of infrared spectroscopy analysis and thermal gravimetric analysis. The IR analysis shows that associated hydroxyl is disappeared, Ar-H is decreased substantially, and methyl and methylene of the ring structure are changed greatly in the molecule of pre-oxidized silk. The TG analysis shows that the first weight loss temperature is increased, weight loss temperature range is moved to the higher temperature direction, the total weight loss rate is decreased, and weight loss velocity is decreased substantially. The mechanical performance of carbon fiber is affected by the pre-oxidation heating rate. When pre-oxidation heating rate is 1.5°C/min, the breaking strength of carbon fiber is 1195.84Mpa and the Young's modulus is 80Gpa.