Tensile and flexural characteristics of an epoxy-glass composite reinforced with Cloisite 15A nanoclay

Abstract

Nanoclay weight percent, glass fiber volume percent and angle of orientation of fibers were selected as parameters to study their effect on tensile and flexural characteristics of epoxy-glass-clay nanocomposites (EGCNs). Response surface method (RSM) was utilized to analyze and fit a regression model for the tensile and flexural strength. The optimum values of ultimate tensile strength (UTS) and flexural strength (σf) were 273.47 and 210.14 MPa, respectively, which were predicted using regression models at 2.5% (by wt) of nanoclay, 31.5% (by vol) of glass fiber and 0°/90° of fibers orientation. The predicted results were confirmed by performing experiments at the optimum conditions which were obtained as 262.37 and 214.76 MPa. The optimized result showed that UTS and σf were improved up to 30.8% and 36.3% compared to the composite containing 0% (by wt) of nanoclay, 31.5% (by vol) of glass fiber and 0°/90° of fibers orientation. The optimum values of tensile and flexural modulus were obtained as 25.99 and 11.81 GPa, respectively, which were 12.2% and 10.7% higher compared to those values of EGCN containing 0% (by wt) of nanoclay, 31.5% (by vol) of glass fiber and 0°/90° of fibers orientation. XRD test conducted to check the intercalation/exfoliation of the clay in the composite. The fracture surfaces of the EGCNs investigated by scanning electron microscopy (SEM) revealed that the failure occurred by crack propagation in the matrix followed by fiber breakage with little fiber-matrix debonding, whereas in case of EGCN with 0% (by wt) C15A fiber-matrix debonding followed by fiber breakage was observed.