Transparent wood composite prepared from two commercially important tropical timber species

Abstract

Transparent wood (TW) has garnered significant global attention due to its unique properties. In this study, TW composites were fabricated using two timber species of different density classes: Ailanthus triphysa (common name: Ailanthus wood) and Hevea brasiliensis (common name: Rubberwood). Sodium hydroxide (NaOH) and Hydrogen peroxide-based alkali method was used to modify the lignin in these veneer samples, producing a white cellulose template with a fully intact hierarchical cell structure. Subsequently, a cost-effective thermosetting unsaturated polyester resin (UPR) was infiltrated into the redesigned framework and polymerized to create rigid nanostructured transparent composites. High optical haze (of 94% and 89%) and favourable light transmittance of 59 and 55 percent were exhibited by the UPR-TW composites made from rubberwood and ailanthus wood, respectively. TW was characterised using Scanning electron microscopy and Fourier-transform infrared spectroscopy. The mechanical properties of TW were measured and compared with those of natural wood and pure-polymer. Furthermore, the anisotropic light diffusion behaviour displayed by TW in accordance with the fibre orientation indicates the utility of material as a potential light shaping device. Therefore, a cost-effective and commercially viable strategy to fabricate multipurpose TW composites using a combination of lesser-known timber species (LKTS) and UPR resin was successfully demonstrated.