Study On Structure And Properties Of Aramid Fiber â…¢

Aramid fiber, as a kind of high-performance fiber materials, has been widely used in many industries and military fields. Domestic aramid fiber III is a new type of improved varieties of aramid fiber, it embed the third unit cell in the synthesis of macromolecular chain of poly-para-phenylene terephthalamide. This paper has studied the main properties of the new type aramid fiber III through a series of analysis methods to get the main performance parameters. It compares these properties of domestic aramid fibre III with domestic aramid 1414 fiber, imported Twaron fiber and domestic aramid 1313 fiber to get its performance advantages, and puts forward the defects of its structure, and provides reference for the research and development in the future. The results show that:(1) The state of aggregation structure of domestic aramid fibre III has the very good orientation, orientation degree is higher than the other three kinds of aramid fiber, but its crystallinity is low, crystal zone is not perfect and contains paracrystal; According to the infrared spectra of aramid fiber III, its macromolecular chain contains benzimidazole ring.(2) Domestic aramid fiber III is an ideal fiber material with high strength and high modulus, its strength is close to 1.5 times that of para-aramid fiber and its modulus is higher than the other three kinds of aramid fiber. Under the high temperature and high concentration of acid treatment, the amide linkage in the macromolecular structure will appear the phenomenon of hydrolysis, but it still showed good resistance to acid; Under the high temperature of alkali treatment, domestic aramid fiber III showed excellent alkali corrosion resistance. Thus, it will be very suitable for high temperature filtration materials in the future.(3) The surface of domestic aramid fiber III contains uneven shallow grooves, and it is rougher than the two para-aramid fiber’s, the wettability of the surface is poor, but better than the other three kinds of aramid fiber. Modifying the surface of aramid fiber III by plasma can reduce its surface contact Angle from 55.8?to 41.5?, the wettability of fiber is improved very well, thus the bond strength of the fiber and matrix in the domestic aramid fiber III reinforced composite materials is improved.(4) The thermal stability of domestic aramid fiber III is good, its initial decomposition temperature is about 465℃.The DSC curve shows that when the temperature rises to about 531℃, it appears cracking, when heated to 900℃, the phenomenon of fiber carbonization occurs but hardly don’t melt, and the quality of residual amount is 58%, the weightlessness rate is minimal in the four kinds of aramid fiber in this topic research.The study of domestic aramid fiber III in this topic is based on the main performance in the current application of aramid fibers, it provides reference for the further development and the utilization of domestic aramid fibre III.