Characterization of wood and wood-plastic composite

Wood-plastic composites (WPC) were prepared with low-grade wood (kadom, sim ul, and mango) of Bangladesh and MMA (methyl methacrylate) under Co-60 gamm a irradiation with a 3-Mrad dose (800 krad/h), Polymer loading and tensile properties of the composites were determined and the effect of urea and N-v inyl pyrrolidone (NVP) on these properties was studied. The polymer loading (PL) increases slightly (2-3%) with the addition of urea to the MMA + MeOH solution; however, this increment is 6-16%with NVP addition and 12-54% wit h urea + NVP, depending on the type of wood. Similarly, the tensile strengt h (TS) increased by 11-25%, the bending strength (BS) by 31-48%, and the co mpressed strength (CS) by 40-67%. To further characterize the composite, th e samples were investigated with infrared (IR), electron-spin resonance (ES R). and thermally simulated luminescence (TSL) techniques. IR studies revea l that MMA was grafted with the wood substrate: ESR and TSL investigations detected the residual free radicals (not the primary free radicals) in the composites.