Optical and mechanical properties of multilayered transparent wood

Abstract

The versatility of utilizing transparent wood composite (TWC) as structural building component has been envisioned by producing thicker section. The challenges and limitation while preparing transparent wood using thick wood sections can be addressed by the concept of multilayered construction. TWCs were produced using 2 mm thick lignin modified wood veneer sections of three wood species viz., Populus deltoides (Poplar), Melia dubia (Melia) and Grevillea robusta (Silver oak) followed by infiltration of epoxy polymer. To increase the thickness of composite, an easy method of multilayer construction of 2 mm thick epoxy infiltrated wood samples to produce thicker TWC composite was adopted. Assembly of 2 mm thick epoxy infiltrated wood samples one above the other to produce two layer (4 mm thickness), three layer (6 mm thickness) and four layer (8 mm thickness) thicker TWC of Poplar, Melia and Silver oak wood was carried out. The optical transmittance of TWC samples was measured using UV–VIS–NIR spectrophotometer equipped with an integrating sphere. The optical transmittance of multilayered TWC was reduced on increasing number of layers. The three-point static bending test of multilayer TWC indicated an improvement in flexural strength and slight decrease in the modulus of elasticity on increasing number of layers.