▎ 摘　　要

Wood plastic composites (WPCs) consisting of high-density polyethylene (HDPE) reinforced with alkali-treated sugarcane bagasse fibers (BF) in a concentration of 30 parts per hundred parts of plastic (php) were fabri-cated using the melt-blending technique. The carbon black (CB) was added at a concentration of 10 php while the graphene oxide nanoparticles (GO) were added in different concentrations (0.25, 0.5, 0.75, and 1 php). The influence of these additives and electron beam irradiation at different doses (100 and 200 kGy) on the flexural properties, electrical conductivity (sigma dc), and electromagnetic interference (EMI) shielding efficiency of the HDPE/BF composite were investigated. The samples were examined under microwave signals in the range from 0.8 GHz to 3.5 GHz to study the shielding effectiveness. The maximum flexural strength (29 MPa) was recorded for the HDPE/BF/CB composite, which contains 1 php of GO and was irradiated at 100 kGy with an improvement percentage of 56.6% in comparison with that of the unirradiated HDPE/BF composite. The addition of GO improved the electrical conductivity and EMI shielding efficiency of the prepared composite. It was observed that at frequency 3 GHz, the increase of GO up to 1 php enhanced the shielding effectiveness by a factor of 17.35% and 16.94% at 0 and 200 kGy, respectively. Furthermore, increasing the irradiation dose increased shielding effectiveness by about 4.92%.