Fabrication and evaluation of carbon nano fiber filled carbon/epoxy composite

In the present investigation, carbon nano fibers (CNFs) were infused into part-A of SC-15 epoxy (diglycidylether of bisphenol A) through a high intensity ultrasonic liquid processor and then mixed with part-B of SC-15 (cycloaliphatic amine hardener) using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. DMA, TGA, and tensile tests were performed on unfilled, 1, 2, and 3 wt.% CNF filled SC-15 epoxy to identify the loading effect on thermal and mechanical properties of the matrix. The tensile results indicated that 2.0 wt.% CNF/epoxy resin showed the highest improvement in strength as compared to the neat systems. After that, the nanophased matrix with 2 wt.% CNF was then utilized in a vacuum assisted resin transfer molding (VARTM) set up with satin weave carbon preforms to fabricate laminated composites. The resulting structural composites have been tested under flexural loads to evaluate mechanical properties, and 22.3% improvement in flexural strength was observed in nanocomposite. Based on the experimental result, a linear damage model has been combined with the Weibull distribution function to establish a constitutive equation for neat and nanophased carbon/epoxy. (c) 2006 Elsevier B.V. All rights reserved.