Wood-polymer composites prepared by free radical in situ polymerization of methacrylate monomers into fast-growing pinewood

The aim of this study was to evaluate treatability, morphology and mechanical resistance of composites prepared by in situ polymerization of methyl methacrylate on Pinus taeda wood using glycidyl methacrylate and methacrylic acid as cross-linkers. Treatment consisted of impregnation by vacuum/pressure and polymerization at 90 °C for 10 h using heat catalyst. The treatability was characterized by loads of monomers, conversion of monomers to polymers, weight percent gain, permanent swelling, and densification. The morphology was characterized by SEM images, X-ray diffraction, confocal Raman microscopy, and mechanical properties by static bending, shore D hardness and brittleness tests. Composites with cross-linkers showed the highest monomers retention, and the highest conversion. Brittleness of the composites increased significantly, modulus of elasticity increased from 17 to 32 %, flexural strength increased by 22.4–45.3 %, and shore D hardness increased between 60.2 and 89.6 %. The GMA cross-linker provided the highest increments for mechanical resistance.