热解沉积结合PAMAM接枝改性碳纤维表面

摘要

采用热解沉积结合聚酰胺-胺型树枝状高分子(PAMAM)接枝的改性方式对碳纤维进行表面处理,对比了碳纤维原丝(CFs)、只经热解沉积处理碳纤维(PD-CFs)和沉积结合接枝处理碳纤维(PD-PG-CFs)的表面形貌、表面元素组成和质量分数、与极性液体和非极性液体的接触角、表面自由能的变化;制备了不同处理条件下碳纤维/环氧微复合材料,与未处理的碳纤维原丝相比,经热解沉积处理的碳纤维/环氧复合材料的界面剪切强度(IFSS)提高了26.87％,而经沉积结合PAMAM接枝处理碳纤维/环氧复合材料的IFSS则提高了38.81％.通过纳米压痕测试定量的表征了复合材料中碳纤维、热解碳层和树脂基体3者的模量,结果表明,热解碳层的模量介于碳纤维和树脂之间,它所起到的过渡层效应是复合材料界面性能得到改善的重要原因.%The surface of carbon fiber was modified by combination of pyrolytic deposition and PAMAM polyamide-amine dendrimergrafting.The surface morphologies,the surface element composition and content,the contact angle to polar and nonpolar liquid and the surface free energy of pristine carbon fiber (CFs),pyrolytic deposition treated CFs (PD-CFs) and deposition and PAMAM grafting CFs (PD-PG-CFs) were investigated and compared,respectively.The carbon fiber/epoxy micro composites were fabricated.Compared to the pristine CFs,the interfacial shear strength (IFSS) of PD-CFs/epoxy composite was improved by 26.87％,while that of PD-PG-CFs was increased by 38.81％.The modulus of carbon fiber,pyrolytic carbon layer and resin matrix in composites were quantitatively characterized by nanoindentation technology.The results show that the modulus of pyrolytic carbon layer is between carbon fiber and resin,whose transition layer effect significantly contribute to the enhancement of the composites interface performance.