高等学校化学学报2017，Vol.38Issue(1)：150-158,9.DOI:10.7503/cjcu20160580
热亚胺化过程中气氛和拉力对BPDA-PDA聚酰亚胺纤维结构与性能的影响
Influence of Atmosphere and Force During Thermal Imidization on the Structure and Properties of BPDA-PDA Polyimide Fibers†
摘要
Abstract
The process of thermal imidization of polyamideacid ( PAA) fibers affects the properties of the obtained polyimide ( PI ) fibersdirectly. Herein, the influence of atmosphere and force during thermal imidization on the structure and properties of PI fiber derived from 3,3′,4,4′-biphenyltetra-carboxylic dian-hydride(BPDA) and p-phenylenediamine(PDA) was studied. As PI fibers isothermally treated for 5 min, though there is no apparent difference on the morphology of their surface at different atmospheres, the highest tensile strength and initial modulus of fibers treated under nitrogen can reach about 1. 25 and 65. 0 GPa which are better than those treated in the air, indicating an effective protection of nitrogen atmosphere on the fiber. As longer treatment time of 40 min was applied, the protection of nitrogen atmosphere on the fiber surface was visible in the scanning electron microscopy( SEM) images. However, for the mechanical properties, the effect of atmosphere was only remarkably when fibers treated at 450℃. As PAA fibers treated at temperatures lower than 450 ℃, the long-time treatment became the main factor to influence the mechanical properties. And as PAA fibers treated higher than 450℃, the mechanical properties were lowered since the degradation of fibers in both atmospheres. As force is applied during the thermal imidization, the expansion of fibers during imidiza-tion can be enhanced. With increasing the applied force from 0. 0025 N to 0. 32 N, the length of the obtained PI fibers increases from 5. 0% to 15. 5% and the diameter decreases from 16. 0μm to about 12. 8μm. Moreo-ver, it is found that all of the d-spacing of the (004) crystals faces, the crystal size along the fiber axis, the absolute value of coefficient of thermal expansion( CTE) and temperature of glass transition( Tg ) of the fibers increase with the applied force. The tensile strength of fibers seems insensitive to the applied force and remains at about 0. 90 GPa. The elongation decreases slightly from 2. 50% to 2. 30% and the initial modulus increases from 53. 0 GPa to 65. 0 GPa as the applied force increases.关键词
聚酰亚胺纤维/聚酰胺酸/热亚胺化/气氛/拉力Key words
Polyimide fiber/Polyamic acid/Thermal imidization/Atmosphere/Force分类
化学化工引用本文复制引用
杨文轲,刘芳芳,张恩菘,邱雪鹏,姬相玲..热亚胺化过程中气氛和拉力对BPDA-PDA聚酰亚胺纤维结构与性能的影响[J].高等学校化学学报,2017,38(1):150-158,9.基金项目
国家“九七三”计划项目（批准号2014CB643603）和国家自然科学基金（批准号51173178）资助． （）
