Effect of filler loading and orientation on alkali-treated cornhusk film reinforced epoxy laminate composites

Abstract

Cornhusk film (CHF) has been used as reinforcement in epoxy matrix to develop CHF-epoxy laminate composites (CHFEC). Subsequently, the influence of CHF loading by weight (3%, 6% and 9%) as well as the angle of orientation (0⁰, 45⁰ and 90⁰) of its ridges on the dynamic mechanical properties of the composites has been studied. Alkali-treated CHF results in better CHF/epoxy interphase and shows improvement in composite performance. Strength-to-weight ratio (SWR) of alkali-treated CHF is increased by 7.2% as compared to that of untreated one. Dynamic mechanical analysis shows best results for 6wt% CHF loaded composites with 372 MPa storage modulus as compared to that with 212 MPa for neat epoxy. The positive shift in tan δ peak of around 8.2 °C for the composites validates the effectiveness of CHF as a reinforcing agent in epoxy matrix. The maximum increase in storage modulus is found up to 75.47%, and it retains 4 times its value in rubbery zone as compared to neat epoxy. The CHF-epoxy composites retain their homogeneity, which is further improved at higher angle of orientation of CHF. The predicted viscoelastic properties of composites from the theoretical expressions are in line with the actual results. Results of statistical analysis show that CHF loading and its orientation in the laminate are significantly affecting the overall properties of the composites. The maximum moisture absorption is found ~ 1.024%, which is much lower than the permissible standards for wood-polymer composites. CHF based epoxy laminate composite structures can be used for developing partitioning panels, decking and similar applications.