Flexible transparent wood prepared from poplar veneer and polyvinyl alcohol

The fabrication of transparent wood (TPW) has generated lot of interest in the recent past due to its favorable physical, mechanical and fascinating optical properties. The present work, describes a ‘green’ method to fabricate a biodegradable and highly flexible transparent wood-polymer composite from poplar wood veneers and polyvinyl alcohol (PVA). In this method, the wood veneers are chemically treated under mild conditions to remove the light-absorbing components in wood without damaging the hierarchical wood structure. Then, the mesoporous template structure of bleached wood is infiltrated with an aqueous PVA dispersion and dried to obtain flexible TPW. The effect of plasticizing PVA with propylene glycol (PG) on the mechanical and optical properties of TPW has been studied. The flexibility of TPW increased with increase in PG content in PVA. The TPW prepared from the aqueous dispersion of PG:PVA (1:1) exhibited optical transmittance as high as 80% and haze of 90% with excellent flexibility, optical and mechanical anisotropy. The potential application of such optically anisotropic and flexible wood-polymer composite as light shaping diffuser is successfully demonstrated.