变温拉曼研究炭纤维增强聚酰亚胺复合材料的界面微观力学行为（英文）

Temperature-variable Raman scattering study on micromechanical properties of the carbon fiber reinforced polyimide composite film

采用变温拉曼光谱mapping扫描技术研究了在升温过程中炭纤维(CF)增强聚酰亚胺(PI)/碳纳米管(CNTs)复合材料的微观力学行为。其中CF为增强材料,CNTs作为应力传感媒介,两者都具有拉曼温度敏感性。获得了各温度条件下(25～300℃) CF/CNTs-PI复合材料界面微区的应力分布变化图。在200℃以下,CF/CNT-PI薄膜中纤维与界面区域压应力分别在122 MPa与74 MPa附近,应力分布从纤维到基体逐渐减小。200℃为残余应力消除温度,CF/CNT-PI薄膜内部应力接近于0 MPa。然而,当加热超过200℃时,薄膜主要承受拉应力,且主要分布在CF上。此外,发现CF与基体之间的应力传递小于100%。这些结果均证明复合材料中的应力随温度而变化,而CF具有优异的增强作用。

Temperature-variable Raman spectroscopy equipped with mapping function was used to investigate the micro-mechanical properties of a carbon fiber(CF)reinforced polyimide(PI)composite film using carbon nanotubes(3 wt%)dispersed in PI as the stress sensor.The stress distributions on CFs and the interface region during heating from 25 to 300 ℃ were mapped based on the stress sensitive Raman G'band(around 2679 cm^-1 )shifts of CNTs.Results indicate that thermal motion of PI chain affect the mechanical properties when the CF/CNT-PI film was heated up to 300 ℃.Both CFs and interface region were compressively stressed below 200 ℃.The compressive stress decreased with temperature and was approximately eliminated at around 200 ℃.Tensile stress developed above 200 ℃ and increased with temperature,which was distributed mainly on CFs.Furthermore,the stress transfer between CFs and matrix was less than 100% due to the thermal stress hysteresis in the PI matrix.