Mechanical and thermal properties of glass fiber-reinforced epoxy composite with matrix modification using liquid epoxidized natural rubber

Glass fiber epoxy composites are widely used in industries. Liquid epoxidized natural rubber was added to epoxy as the matrix for a fiber-reinforced composite in order to improve its mechanical properties whilst E-glass fiber was used as the composite reinforcement. Flexural test, Izod impact test, tensile test, thermogravimetric analysis, and scanning electron microscopy were performed to investigate the effect of liquid epoxidized natural rubber addition and glass fiber loadings on the mechanical properties of the composite. It was observed that the flexural strength and flexural modulus of the samples increased with increasing glass fiber percentage with 9% as the maximum weight percentage recorded. The tensile strength and Young's modulus increased with increasing glass fiber content until it reached the maximum value at 9 wt% of glass fiber. The same trend was observed with the impact value of the samples. All the tests were conducted for the composite with and without liquid epoxidized natural rubber addition. The presence of liquid epoxidized natural rubber improved the mechanical properties of the composites due to the plasticizing effect of the rubber particles in the matrix. Thermogravimetric analysis revealed the thermal stability of the composites whilst the scanning electron microscopy shows a heterogeneous dispersed phase of morphology. There was poor adhesion between the matrix polymer and glass fibers due to the use of untreated glass fibers.