Effect of ADG-NH2 functionalized graphene on fracture and impact resistance of carbon fiber reinforced composites

In this study tensile, single edge notch beam [SENB] and impact tests were done as per ASTM standards to evaluate the influence of the ADG-NH2 functionalized Nano additives on the mode I fracture and impact resistance characteristics. This study highlights the enhancement in the Tensile strength, Mode I fracture resistance and impact strength properties of Carbon Fiber Reinforced Polymer [CFRP] composites loaded with Lower concentration of Graphene reinforcement. Five symmetrical, modified composite laminates [ADG-NH2/Epoxy/CFRP] were fabricated using a hand layup process supported by vacuum bagging. These laminates incorporated various weight content [0.25, 0.5, 0.75, and 1%] of ADG-NH2/Epoxy along with a neat epoxy for comparison. Notable improvements were observed in the composite properties with 0.5 wt% ADG-NH2 graphene Nano-additive reinforcement in comparison with base epoxy CFRP composite laminates, including increase in elastic modulus by approximately 18%, rise in ultimate tensile strength by around 21%, enhanced elongation at break by roughly 19% and Improved toughness, showing a 28% gain. An enhancement of ~29 % and ~ 60% were observed for the fracture resistance [KIC & GIC respectively] of base epoxy resin [value of ~ 0.67 MPa m1/2 and ~157 J/m2 respectively] with 0.5 wt% ADG-NH2 loading obtaining a value of ~ 0.86 MPa m1/2 and ~251 J/m2 respectively. Similarly, enhancement of ~ 41% was observed for the impact strength of base epoxy resin [value of ~77 J/m2] with 0.5 wt% ADG-NH2 loading obtaining a value of ~108 J/m2. Morphological properties of fracture surfaces were characterized by SEM micrographs analysis.