Effect of Draw Ratio on the Morphologies and Properties of BPDA/PMDA/ODA Polyimide Fibers

• Published in: Chemical research in Chinese universities 2014-02, Vol.30 (1), p.163-167
• Main Authors: Zhang, Chunling, Zhang, Qiong, Xue, Yanhu, Li, Guomin, Liu, Fangfang, Qiu, Xuepeng, Ji, Xiangling, Gao, Lianxun
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Inorganic Chemistry; ODA; Organic Chemistry; Physical Chemistry; PMDA; 广角X射线衍射; 拉伸弹性模量; 拉伸比; 机械性能; 聚酰亚胺纤维; 酰亚胺化反应
• ISSN: 1005-9040; 2210-3171
• DOI: 10.1007/s40242-014-3266-0

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.