Mechanical properties of short carbon/glass fiber reinforced high mechanical performance epoxy resins

To research the relationship between epoxy and fiber inherent property and mechanical properties of composite,we prepared a series of composites using three kinds of high mechanical performance epoxy resins as matrices and reinforced by the same volume fraction(5%)of short carbon and glass fiber.Their mechanical properties were investigated from the perspective of chemical structure and volume shrinkage ratio of epoxy.We analyzed their tensile strength and modulus based on the mixing rule and Halpin-Tsai equation,respectively,and studied the morphology of impact test samples by scanning electron microscope.The results show that chemical bonds formed between matrix and fiber are the most important factor to improve the mechanical properties of composite.High volume shrinkage ratio is also helpful when the fiber surface was coarse.Otherwise,the tensile strength is more sensitive to interface than the tensile modulus.It is concluded that the mechanical properties of composite are strongly affected by the chemical structure of epoxy resin,the volume shrinkage ratio of cured matrices,and properties of fiber surface.