Effect of CaC0₃ on the wood properties of tropical hardwood species from fast-growth plantation in Costa Rica

This work aimed to evaluate the effect of the precipitation of CaCCh via subsequential in-situ mineral formation based on a solution-exchange process of two solution-exchange cycles via impregnation with CaCl2 in ethanol and NaHC03 in water. The effects were investigated in terms of the structure of the wood and the thermal, physical, mechanical, and decay resistance properties of nine species commonly used in commercial reforestation in Costa Rica. The thermogravimetric analysis results showed that the woods with the highest formation of CaC03 showed a more pronounced signal at 200 °C in relation to untreated/wood; therefore, they were more thermostable. The fire-retardancy test showed that flame time in CaC03/wood composites was longer than for untreated/wood in half of the species tested, presenting a positive effect of mineralization. Wood density, decay resistance, modulus of rupture (MOR). modulus of elasticity (MOE) in flexion, and MOR in compression were slightly affected by mineralization. Water absorption increased, but it had no negative effect on the dimensional stability. In general, mineralization can be a chemical treatment to increase the dimensional stability and fire resistance of hardwood species without modifying the wood's physical and (mechanical properties.