Abstract
Multi-walled carbon nanotube (MWNT)/epoxy resin composites have been fabricated by combining with the three different conditions, namely surface acid-treatment on MWNT, cure under pressure and liquid rubber modification. In order to investigate the effects of those three conditions on the mechanical properties of MWNT/Epoxy composite with different weight percentages of MWNTs, the tensile test and the three-point bending test have been carried out. The fracture surfaces have been observed by using scanning electron microscope (SEM). As a result, it is shown that since the surface acid-treatment is effective in improving the dispersion of MWNT in polymer and the interfacial bonding properties between MWNT and polymer matrix, the surface acid-treatment is useful to increase the maximum tensile stress and the critical strain energy release rate. The cure under pressure has a positive effect to reduce the number of voids in the composite, which have the decisive role in the fracture behavior. The liquid rubber modification increases the failure strain with declining the maximum tensile stress. Moreover, since the liquid rubber modification is effective to improve the reinforcement capability of MWNT, the liquid rubber modification markedly increases the critical strain energy release rate.
