氨气处理碳纤维 第II报 碳纤维表面和复合材料的性能

常压下,使碳纤维通过以氨气为气体介质的600℃热反应炉,反应停留时间为30s。采用三点短梁法和界面评价装置研究处理前后复合材料的层间剪切强度(ILSS)和界面剪切强度(IFSS),经氨气处理后二者分别提高了13.2%和32.1%。接触角测试结果表明:处理后碳纤维与水和环氧树脂的浸润性得到很大改善。采用扫描电子显微镜(SEM)研究处理前后碳纤维表面和复合材料断裂面形貌的变化,发现氨气处理对碳纤维表面形貌没有影响。力学性能测试数据表明,氨气处理不影响碳纤维的强度。

Effect of Free Ammonia Treatment on the surface Properties of Carbon Fibers and its Composites

The carbon fibers (CFs) were treated for 30 s at 600 ℃ under the normal pressure of the NH3 gas in the thermal furnace. After treated by NH3, the interlaminar shear strength (ILSS) and the interfacial shear strength (IFSS) of CF-reinforced resin composites (CFRP) increased by 13.2 % and 32.1 % respectively, found by three-point-bending approach and the equipment for fiber/resin composite interface properties evaluation. The contact angles of CFs indicated that the soack of CFs were remarkably improved in water or epoxy resin solution. The surface of CFs and the fractured surfaces of CFRP were studied by scanning electron microscope (SEM). The surface of CFs treated by free ammonia had no change compared with that of the untreated CFs. The mechanical analysis showed no effect on strength of CFs after treated by free ammonia.