Abstract
In this study, carbon dioxide (CO2) was sequestered in the curing of wood-sodium silicate (SS) composites. The effect of carbonation curing pressure, reaction time, wood fiber particle size, and post curing temperature on the thermal and mechanical properties of wood-SS composites was investigated. A mixture of 50 wt % wood (40 and 200-mesh) and SS was used to fabricate composites that were considered for carbonation curing. Dynamic rheological behavior of the blends during isothermal curing showed a higher complex viscosity for CO2-treated samples. X-ray microcomputed tomography (micro-CT) scans showed an increased CO2 penetration depth with carbonation time and pressure. The %CO2 uptake for wood-SS samples increased with the CO2 exposure time and pressure. Curing kinetics of neat SS and wood-SS composites of different wood contents (50–70 wt %), examined using modulated dynamic scanning calorimetry (MDSC), showed activation energies ranged from 85 to 125 kJ/mol. The flexural properties of the 200-mesh wood-SS composites were higher with flexural modulus between 0.8 to 11.2 GPa and flexural strength between 3.5 to 59.2 MPa. Statistical response surface methodology showed that the CO2 pressure and exposure time had significant effects on the mechanical properties of carbonated cured wood-SS composites.