高等学校化学研究 ›› 2014, Vol. 30 ›› Issue (1): 163-167.doi: 10.1007/s40242-014-3266-0
ZHANG Chunling1,2, ZHANG Qiong1,2, XUE Yanhu3, LI Guomin2, LIU Fangfang2, QIU Xuepeng2, JI Xiangling3, GAO Lianxun2
ZHANG Chunling1,2, ZHANG Qiong1,2, XUE Yanhu3, LI Guomin2, LIU Fangfang2, QIU Xuepeng2, JI Xiangling3, GAO Lianxun2
摘要:
3,3,4,4-Biphenyltetracarboxylic dianhydride/pyromellitic dianhydride/4,4-oxydianiline(BPDA/PMDA/ ODA) polyimide copolymer fibers with different draw ratios were prepared from the imidization of polyacrylic acid(PAA) fibers via a dry-jet wet-spinning process. Their morphologies, microcrystal orientations, thermal stabilities, and mechanical properties were investigated via scanning electron microscopy(SEM), wide angle X-ray diffraction(WAXD), thermogravimetric analysis(TGA), and tensile experiments. In order to acquire fibers with better mechanical performance, we aimed at obtaining the optimal draw ratio. Drawing during thermal imidization resulted in a decreased diameter of fiber from 25.8 μm to 16.9 μm corresponding to draw ratio from 1 to 3.5. WAXD results show that the degree of the orientation of the undrawn sample is 64.1%, whereas that of the drawn sample is up to 82%. The as-spun fiber and those with different draw ratios all exhibit high thermal stabilities, i.e., the temperature at a mass loss of 5% can reach as high as 570 ℃. The tensile strengths and tensile modulus of the fibers increase with the draw ratios, and the maximum tensile strength and modulus are 0.90 and 12.61 GPa, respectively.