Comparing the effect of cell wall modification with glycidyl methacrylate and maleic anhydride on the physical, mechanical and biological properties of poplar wood-styrene polymer composite

Wood modification with cell wall modifiers change the practical properties of wood. Likely, changing the modification conditions with chemicals by different reactivity has a more favorable effect on wood properties. This research was conducted to determine the effect of cell wall modification with glycidyl methacrylate (GMA) and maleic anhydride (MA) on practical properties of wood polymer composite. Test samples were divided into ten groups; control, impregnated with styrene, and combined modification of cell wall (GMA and MA) at four concentrations of 10, 20, 30 and 40%/styrene. Cell wall modification, with increase in weight and conversion rate, improved hydrophobicity and dimensional stability of specimens which for GMA was more than MA. With increasing of the GMA concentration from 30 to 40% and cell wall bulking, cracks probably formed in the cell wall that increased water uptake and dimensional changes. The presence of monomer along with modification, by reducing the polarity of wood, uniform distribution of monomer in wood, and improving the adhesion between polymer and wood, increased the mechanical properties of composites, which showed the highest improvement in GMA/styrene. Modification with MA and GMA prevented the fungi mycelium development through reducing hydroxyl groups, changing the hollocellulose structure, and the presence of polymer as a physical barrier. The effect of GMA combined with monomer created more improvement on biological resistance up to 20% concentration, and by increasing the concentration to 40%, it did not show a significant difference with MA. The mechanical properties improvement can be attributed to the formation of polymers with excellent performance and the effect of modification on the cell walls. In most properties, the effect of GMA up to 20% concentration was more than MA, but with increasing concentration and possibly the appearance of cracks in the cell wall, the efficiency of MA modification was higher than GMA.