【摘要】 设计并合成了季铵盐修饰的聚倍半硅氧烷纳米粒子（QA-POSS），并将其添加到聚酰胺酸纺丝液中，纺制了一系列不同Si含量的QA-POSS/PI复合纤维。结果表明，复合纤维具有良好的耐热性能，其5%热失重温度(T_5%)和玻璃化转变温度（T_g）平均值分别为558和395℃。经X射线光电子能谱（XPS）以及电感耦合等离子体光谱（ICP）测试结果表明，复合纤维整体的Si元素含量比复合纤维表面的Si元素含量低，说明Si元素在复合纤维体系呈现梯度分布。当QA-POSS添加质量分数从0%增加到15%时，经3.17×10²⁰ atoms/cm²的原子氧辐照之后，复合纤维表面形貌由粗糙逐渐变得致密完整，质量损失下降明显，从1.40 mg/cm²降低为0.10 mg/cm²。经原子氧辐照之后，QA-POSS-5%的复合纤维显示出最低的力学性能损失(断裂强度保持率为89.36%，初始模量保持率为89.35%，强度衰减率为1.58×10^-13 Pa·cm²/atom)。更多还原

【Abstract】 Herein, polyhedral oligomeric silsesquioxane（POSS） nanoparticles were modified by quaternary ammonium, followed by adding into polyamic acid（PAA） spinning solution. Then series of QA-POSS/PI composite fibers were afforded via wet-spinning process. The as-prepared composite fibers showed good thermal properties with 5% thermal decomposition temperature(T_5%) and glass transition temperature（T_g） values of 558 ℃ and 395 ℃. Based on X-ray photoelectron spectroscopy（XPS） and inductively coupled plasma（ICP） measurement results, the silicon contents on fiber surface were higher than those in total fiber, which indicated that silicon showed gradient distribution in composite fibers. When additive amount of QA-POSS nanoparticles was raised from 0% to 15%, the surface topographies of composite fibers displayed a clear change from roughness to compact, and mass loss decreased obviously from 1. 40 mg/cm² to 0. 10 mg/cm² after AO erosion with the fluence of 3. 17×10²⁰ atoms/cm². Actually, the lowest loss of mechanical properties was seen for the composite fibers when 5% QA-POSS particles were added. Fracture strength and initial modulus retentions of the fibers were 89. 36% and 89. 35%, respectively. And the corresponding decay rate of the strength was seen as 1. 58×10^-13 Pa·cm²/atom.更多还原