耐高温异构聚酰亚胺树脂及其复合材料

采用改性的单体反应物聚合法(MPMR)合成了一系列低黏度、耐高温异构聚酰亚胺树脂, 研究了树脂预聚物分子质量对树脂的高温流变行为、固化后热氧化稳定性的影响, 并对树脂的分子结构及其复合材料的加工工艺性能、力学性能进行了表征。结果表明: 树脂预浸液常温储存期大于两个月, 亚胺化后PI-2纯树脂最低黏度为154 Pa·s, 固化后树脂质量损失5%的温度大于560 ℃; 石英纤维/PI-2树脂基复合材料在室温和500 ℃的弯曲强度分别为917、197 MPa, 弯曲模量分别为29、22 GPa, 拉伸强度分别为760、341 MPa, 拉伸模量分别为32、31 GPa, 压缩强度分别为570、95 MPa, 层间剪切强度分别为62、10 MPa。 

High-temperature resistant isomeric polyimide resins and their composites

Low viscosity and high-temperature resistant isomeric polyimide resins were synthesized by modified polymerization of monomer reactants (MPMR) method. The effect of molecular mass on the rheology of oligmers and thermal-oxidation stability of cured resins was studied. The molecular structure of polyimide resins, the processing and mechanical properties of their composites were characterized. The results show that the shelf life of resin solution is more than two months. The lowest viscosity of PI-2 resin after imidization is 154 Pa·s. The temperature for 5% mass loss of cured resins is higher than 560 ℃. The flexural strength and flexural modulus of quartz fabric/PI-2 composite at room temperature and 500 ℃ are 917 MPa, 197 MPa and 29 GPa, 22 GPa, respectively. The tensile strength and tensile modulus at room temperature and 500 ℃ are 760 MPa, 341 MPa and 32 GPa, 31 GPa, respectively. The compressive strength at room temperature and 500 ℃ is 570 MPa, 95 MPa respectively. The interlaminar shear strength at room temperature and 500 ℃ is 62 MPa and 10 MPa, respectively.