制备工艺对活性碳纤维微观结构和吸波性能的影响

以粘胶纤维为原料,通过碳化、活化处理工艺制备活性碳纤维,采用XRD对其微观结构进行表征,并对其吸波性能进行测试,分析了纤维的微观结构与吸波性能的关系。结果表明,制备工艺对活性碳纤维的微观结构和吸波性能有较大影响。在其它工艺参数保持不变的条件下,随碳化温度的升高,活性碳纤维的石墨化程度和吸波性能均先提高后降低;随活化时间的延长,活性碳纤维内部结构趋向不规整化,对电磁波的损耗能力增强。在活化时间为18min、活化温度为900℃、碳化时间为60min、碳化温度为425℃条件下制备的活性碳纤维的吸波性能最佳,含0.6%(质量分数)纤维的树脂基复合材料在6.3～13.4GHz频率范围内对电磁波有-10dB以下的吸收,在8.5GHz时取得的最大反射衰减为-27.3dB。

Effect of Preparation Technologies on ACF Microstructure and Microwave Absorbing Properties

ACFs are prepared from viscose fibers by carbonization and activation processes.Microstructure and microwave absorbing properties of the resultant ACFs are investigated by XRD and a vector network analyzer,and the relationship between fiber microstructure and absorption effect is analyzed.The results show that ACF microstructure and absorbing performances are greatly affected by preparation processes.When the other processing parameters are constants,ACF crystallization degree and absorbing properties rise at first and then fall with the carbonization temperature increasing.ACF microstructure tends to be irregular,and absorbing effects are improved with the activation time extending.ACFs prepared at the conditions (activation time is 18min,activation temperature is 900℃,carbonization time is 60min,carbonization temperature is 425℃) show the optimum absorbing effect.The epoxy resin composite with ACF content of 0.6wt% has a reflection loss below-10dB in the frequency range from 6.3GHz to 13.4GHz,and the maximum absorption reaches-27.3dB at 8.5GHz.