Surface chemistry and thermo-mechanical analysis of some Nigerian wood species

Surface chemistry, thermal stability and rheological behaviors of Mansonia (Mansonia altissima), Sapele mahogany (Entandrophragma cylindricum), Lagos mahogany (Khaya ivorensis), Utile (Entandrophragma utile), Osan (Aningeria altissima), Obeche (Triplochiton scleroxylon) and Danta (Nesogordonia papaverifera) were determined. Chemical components of the wood surface were investigated using Fourier transform infrared spectroscopy; the infrared spectra obtained differed among species. The holocellulose to lignin ratio was estimated for some of the wood species. Thermogravimetric analysis indicated that thermal stability and the rate at which each wood polymer degraded are wood species dependent. The viscoelastic properties of these wood species were tested while submerged in ethylene glycol solvent under saturated conditions using dynamic mechanical analysis. The results show that at 0.1 Hz, the glass transition temperature of Obeche is 85 ± 1 °C while other species have it at higher temperature. However, ethylene glycol saturated Sapele mahogany has the highest storage modulus from 120 to 0 °C.

• In this study we found out that the infrared spectra obtained differed among species. • The holocellulose to lignin ratio was estimated for some of the wood species. • The rates at which each wood polymer degraded are wood species dependent. • The results show that at 0.1 Hz, the glass transition temperature of Obeche is 85 ± 1 °C while other species have it at higher temperature. However, ethylene glycol saturated Sapele mahogany has the highest storage modulus from 120 to 0 °C.