Enhancement of tensile, flexural and ILSS properties of C-epoxy composites with the addition of ETBN toughener and Af-MWCNTs

The objective of this research is to develop a hybrid composite with a unique combination of features such as tensile, flexural and Interlaminar shear strength (ILSS) properties. It is a present need for components used in underwater, aerospace, defence and automotive applications, as parts are subjected to a variety of loading conditions, including tensile, bending and shearing. Carbon fibre reinforced epoxy (C-epoxy) composite is modified by adding epoxy terminated butadiene acrylonitrile (ETBN) liquid rubber and amino-functionalized multi-walled carbon nanotubes (Af-MWCNTs). With the addition of ETBN, the tensile, flexural and ILSS properties were improved by 38%, 46% and 80%, respectively. The addition of 0.5wt% of Af-MWCNTs improved the tensile and flexural strengths by a maximum of 59% and 61%, respectively. In contrast, the maximum improvement in ILSS of 120% was obtained at 1.0 wt.% of Af-MWCNTs. The unique combination of C-epoxy-ETBN-Af-MWCNTs led to the formation of the serrated surface at the fibre matrix interface, which caused improved energy absorption. The toughening mechanisms which are responsible for the improvement in properties are discussed and the results are validated through finite element analysis (FEA).