The objective of this study was to investigate the performance of alternative sugarcane bagasse particle board (BCP) using castor oil polyurethane resin in comparison with commercial medium density wood particle board (MDP) under natural and accelerated test conditions. The particle boards were evaluated after 12 months of exposure to natural weathering in Pirassununga (21.9965° S, 47.4262° W), Brazil and by an accelerated mold growth test under laboratory conditions. The mold growth was quantified according to the Standards ASTM D 3273-12 (2012) and the results were evaluated by statistical analysis through the Proportional Chances Model (PCM). For both materials, the surface coating with castor oil based bicomponent polyurethane resin was less colonized than the non-coated materials; independent of the particleboard type. Additionally, the bending test shows that the sugarcane bagasse particle boards presents better performance of module of elasticity (MOR) (7.7 MPa) in comparison with the commercial wood particle boards (3.6 MPa) after exposed to accelerated tests for mold colonization. The surface coating with castor oil based polyurethane resin reduces mold growth, therefore these results support the potential use of this alternative resin both as a binder and as a surface coating in these particulate materials. The particle boards fabricated with sugarcane bagasse and castor oil resin presented similar mold colonization compared to the commercial wood particle boards.

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Sibipiruna (Cenostigma pluviosum var. pelthophoroides) trees are common in the São Paulo city urban forest, but they may cause accidents when deteriorated by wood-decaying fungi due to trunk rupture and tree fall. Therefore, this study aimed to evaluate anatomical, physical, and mechanical changes in sibipiruna wood attacked by  Ganoderma australe. Adult trees with basidiomata of this fungus and at imminent fall risk were macro and microscopically analyzed to investigate wood  biodeterioration and resistance mechanisms  (compartmentalization). Physical and mechanical tests  (specific gravity, mechanism of resistance and static bending) were performed. In sibipiruna trees, degradation was observed in the heartwood, being more intense in the region near the pith and more extensive at the stem base, from where basidiomata were collected. Fungal attack was characterized as white pocket rot, i.e. non-selective to cell wall components, causing erosion of the S2 layer from the cell lumen. Decaying wood was also attacked by xylophagous insects, like the subterranean termite Coptotermes gestroi and wood-boring beetles. Wood compartmentalization was characterized by accumulation of extractives. White rot caused significant reductions in specific gravity, modulus of rupture and modulus of  elasticity, which justify the rupture of trees when subjected to external forces, such as strong winds.