Effect of structure and defects of para-aramid fiber on its mechanical properties
poly(p-phenylene terephthalamide)(PPTA)fiber,a new strategic material,has excellent mechanical properties,chemical corrosion resistance and flame retardant properties,and is widely used in aerospace,national defense,civil and other fields.The mechanical properties,relative molecular weight,aggregate structure and fiber surface and internal defects of four samples of para-aramid fibers were studied,and the relationship between properties,structure and defects of fibers was established.The results show that the relative molecular weight of PPTA is one of the important factors affecting the mechanical property of the fibers with the same chemical molecular structure,and the tensile strength and modulus of fibers increase with the increase of the relative molecular weight.The tensile strength of para-aramid is mainly related to its crystallinity,orientation,surface defects and internal microporous defects,among which crystallinity and micro-defects are two important factors.The fiber modulus is mainly related to its orientation,and the influence of crystallinity and fiber internal and external defects on fiber modulus is relatively small.
NETL
NSTL
万方数据
