Feasibility of incorporating treated lignins in fiberboards made from agricultural waste.

This paper studies the feasibility of incorporating treated lignins in fiberboards made from Vitis vinifera as an agricultural waste. The treated lignins are the purified Kraft lignin and the alkaline hydrolyzed Kraft lignin. V. vinifera raw material and its fibers were characterized in terms of chemical composition and the results were compared to other biomass species. The chemical composition of treated lignins shows that they have high purity compared to the lignin raw material. The lignin-V. vinifera fibreboards were produced on laboratory scale by adding powdered treated lignins to the material that had previously been steam exploded. Some of the important properties of fibreboards prepared using the treated lignins as natural adhesives were evaluated. These properties were density, thickness swelling, water absorption, modulus of elasticity, modulus of rupture, internal bond strength. The explored levels of treated lignins vary from 5% to 20%. The results showed that binderless fibreboards, fibreboards made from V. vinifera fibers and alkaline hydrolyzed Kraft lignin have weaker mechanical properties. However, the fibreboards obtained using purified Kraft lignin have good mechanical and water resistance properties which satisfy the requirements of the relevant standards specifications.