Flexural Properties of Epoxy Matrix Composites Reinforced by Milled Fibers

Flexural properties of milled E-glass, S-glass, and high strength carbon fiber reinforced epoxy composites have been studied. As received fibers were chopped and milled by an attrition mill, and their morphologies were evaluated by Scanning Electron Microscope (SEM). The epoxy composites were prepared simply by mixing and stirring 1wt.% of the milled fibers with a conventional hot-cure epoxy resin. The effects of resin system degassing and employing a coupling agent (γ-aminopropyltriethoxysilane or γ-APS) were evaluated based on the flexural properties of the epoxy composites. The SEM micrographs of the fracture surfaces were used to investigate the active toughening mechanisms. The most appropriate flexural properties were obtained for the degassed and modified milled E-glass fiber reinforced epoxy. Its bending strength and tangent modulus of elasticity were enhanced up to 1.22 and 1.20 times in comparison to the pristine one. The current study shows that the composite not only is cost effective, but also offers higher flexural strength and tangent modulus of elasticity