Bonding of Amines to Carbon Fiber Surfaces to Improve and Control Adhesion: A New Paradigm for Adhesion in Carbon Fiber-Epoxy Composite Materials.

摘要

We describe the immobilization of amines at the surfaces of high-modulus, pitch-based carbon fibers via direct, thermal reaction of the amine with the carbon fiber. Fourier transform infrared attenuated total reflectance spectroscopy (FTIR-ATR) and electrochemical measurements are used to demonstrate the immobilization.The influence of these reactions on the interfacial adhesion in carbon fiber-epoxy composite materials is investigated by using these fibers to fabricate composite test specimens with EPON-828 epoxy, and then using an embedded single fiber test to measure the interfacial shear strength between fiber and matrix for fibers that had been derivatized with didecylamine, dodecylamine, 1,9-diaminononane or 1,6-diaminohexane. A rational dependence of interfacial adhesion on the molecular structure of the immobilized amine is revealed. Further, by examining the interfacial shear strength in composites made from carbon fibers that had been derivatized with a mixture of amines, we demonstrate that by judicious choice of the relative amounts of these adhesion-controlling reagents in the derivatization mixture, it is possible to control the interfacial composition, thereby controlling the interfacial adhesion. jg p.3.