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利用3,3′,4,4′-二苯甲酮四羧酸二酐(BTDA)和4,4′-二氨基二苯醚(ODA)合成得到聚酰胺酸(PAA)纺丝液,采用静电纺丝技术制备得到PAA纳米纤维,通过热亚胺化法获得BTDA-ODA型聚酰亚胺(PI)纳米纤维。用扫描电子显微镜(SEM)表征了热亚胺化前后纳米纤维的形貌特征,利用傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)和热重分析(TGA)表征了不同亚胺化温度对PI纳米纤维的化学结构、结晶性能和热稳定性的影响。结果表明,当亚胺化热处理温度较低时,PAA纳米纤维的亚胺化程度较差。当亚胺化温度达到300℃时,PAA纳米纤维的亚胺化程度基本完全。随着亚胺化温度的升高,纳米纤维的结晶度逐渐增强,热稳定性也逐渐升高。
Polyamic acid (PAA) spinning solution was synthesized by using 3,3 ’, 4,4’-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4’-diaminodiphenyl ether (ODA) PAA nanofibers were prepared by electrospinning and BTDA-ODA polyimide (PI) nanofibers were obtained by thermal imidization. The morphologies of the nanofibers before and after thermal imidization were characterized by scanning electron microscopy (SEM) and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) Effect of imidization temperature on the chemical structure, crystallinity and thermal stability of PI nanofibers. The results show that the degree of imidization of PAA nanofibers is poor when the imidization temperature is low. When the imidization temperature reaches 300 ℃, the degree of imidization of PAA nanofibers is almost complete. With the increase of imidization temperature, the crystallinity of nanofibers is gradually increased, and the thermal stability is also gradually increased.