Impact of gamma radiation and multi-walled carbon nanotubes on the mechanical and acoustical properties of reinforced sisal fiber/polyester resin composites

Abstract In this work, the effect of exposure to 5 kGy of Gamma radiation and the addition of Multi-walled carbon nanotubes (MWCNT) in different concentration 0, 0.2, 0.4 and 0.6 wt% to sisal fiber/unsaturated polyester resin (SF-UP) composites (40/60) on the mechanical and acoustical properties was investigated. An enhancement in the mechanical properties was achieved by addition MWCNT up to 0.4%, and then decreased at 0.6%. Also, irradiation of the composite manifested an enhancement in the mechanical properties more than unirradiated ones. The tensile strength and flexural strength of irradiated SF-UP composite which contains 0.4% MWCNT were higher than unirradiated SF-UP composite which contains 0% MWCNT by 73.2 and 91.9%, respectively. The addition of MWCNT and exposure to 5 kGy of gamma radiation increased both the storage modulus and the Tg while the damping factor (tan δ) decreased. Increasing the MWCNT % enhanced the sound absorption at the higher frequencies (0.6% MWCNT (unirradiated)∼0.9 within 5000–6300 Hz), while the irradiation shifted the highest absorption toward lower frequencies (0.6% MWCNT (irradiated)∼0.63 within 2500–3150 Hz). The produced composite displayed appreciable mechanical and acoustical properties which makes it as a new partner for many advanced industrial applications.