High Heat Resistance Carbon Fibre/Epoxy Composites Toughened by Thermoplastic Modifiers

Abstract

In this study, DGEBA liquid epoxy was modified with two different modifiers, which were epolec® and Phenoxy. Modifiers dispersion was controlled by the temperature during stirring with adequate rotation rates. The prepreg in this paper were fixed with FAW and resin content and made by drum winding machine. Composite specimens were prepared by the cure conditions determined from Differential Scanning Calorimeter (DSC) which was used to estimate the curing cycle of these matrix systems. Dispersing condition of added particles with their particle sizes were inspected by Small Angle X-ray Diffraction (SAXRD) and Atomic Force Microscopy (AFM) respectively. Differential Scanning Calorimeter (DSC) was adopted to examine the effects of modifiers on the reactivity and glass transition temperature. The shear properties of cured composites were demonstrated by the interlaminar shear strength (ILSS) as well as the Mode I and Mode II fracture toughness. After testing, these fractured specimens were examined biz the Variable Vacuum Scanning Electron Microscope (VVSEM). Results show that the each resin system can be dispersed well by the control of mixing temperature with simple stirring condition. Glass transition temperature of each cured resin systems showed a slight influence with the different test concentrations. In general, the shear properties of cured composites were improved with modifiers being in the cured systems especially in the part of performance of fracture toughness.