碳纤维表面改性研究.pdf

西南科技大学硕士研究生学位论文第1页摘要碳纤维增强复合材料(CFRP)是目前最具有发展前景的非金属材料,其整体性能是否能够充分发挥,关键在于两相间的界面性能。未经表面处理的碳纤维表面光滑,呈现化学惰性,缺乏有化学活性的官能团,限制了其与树脂基体形成良好的界面粘结。本文采用液相氧化、化学接枝和等离子体接枝等方法对碳纤维表面进行改性处理,采用正交设计对碳纤维表面接枝处理的工艺条件进行了优化,表面结构和形貌有明显变化,活性增大,以期进一步提高碳纤维增强复合材料的性能。:利用红外光谱(FT-IR)对处理前后碳纤维的化学结构进行了分析。结果表明,碳纤维经不同方法改性后表面含氧官能团增多,且化学接枝和等离子体接枝改性处理后,碳纤维表面接枝上了马来酸酐的特征峰。采用拉曼光谱(Raman)研究了碳纤维表面处理前后微晶尺寸的变化,改性后碳纤维表面无序度增大,晶棱数增多,表面微晶尺寸呈现不同程度的减小。采用X射线衍射(XRD)研究了表面改性对碳纤维内部结构的影响。碳纤维经过***氧化及化学接枝联合处理后,其内部结构无明显变化;等离子体接枝改性后, 碳纤维的(002)衍射峰强度降低,d002略微变大,说明碳纤维表面石墨化程度和规整性降低。采用扫描电镜(SEM)对改性前后碳纤维表面进行形貌观察发现,处理后碳纤维表面沟槽变深和增多,且碳纤维表面的粗糙度增加。随着***氧化时间的延长,碳纤维表面由粗糙变得光滑,颗粒状物质先增多后减少。化学接枝和等离子体接枝都能使碳纤维表面接枝上不均匀的接枝薄层,可以提高碳纤维与树脂基体间的物理咬合作用。通过对碳纤维在不同条件下表面处理的研冠揭示碳纤维改性过程中的改性机理,从而实现对碳纤维表面性能的优化控制,为制备高性能碳纤维增强复合材料提供理论依据和实验数据支撑。关键词:碳纤维氧化表面接枝马来酸酐改性机理西南科技大学硕士研究生学位论文第1I页 Abst ract Carbon fibersreinforced plastic(CFRP)is themost potential non—metallic property ofinterface between carbon fibers and matrix plays an important role on the general property fibers without any surfacetreatment can limittheadhesion between carbon fibersandmatrix due to thesmooth,chemical inertness and the lack ofactive functional groups. In this study,we employ threemethods:liquid-phase oxidation,chemical grafting,and plasma grafting,to improve the carbon fibers surface;the orthogonal design was used foroptimizing the conditions of carbon fibers surface grafting,the surface structure and morphology ofcarbon fibers has obvious changes,activity increased,which furtherimprove theperformance of CFRE The chemical constructions ofthetreated and untreated carbon fibers were examined by FT- was found that the surface oxygen—containing functional groups increased by differentmodification,and carbon fibers were grafted thecharacteristic peak ofmaleic anhydride by chemical grafting and plasma changes ofcrystallite size were studied through Raman modification,the surface disorder ofcarbon fibersincreased, crystallite sizedecreased and t