Characterization of date palm lignocellulosic by-products and self-bonded composite materials obtained thereof

• Valorization of four date palm tree by-products: fibrillum, leaflets, rachis and leaf sheath.
• Chemical and morphological characterization of the date palm tree by-products.
• Manufacturing of particleboard composites by thermopressing without any pretreatment of addition of synthetic binders.
• The produced composites showed satisfactory mechanical properties.

In the present work, we investigated the possibility of valorizing four date palm tree by-products: leaflets, rachis, leaf sheath and fibrillum as self-bonded materials. First, their chemical composition and morphological properties were studied and showed high neutral detergent fiber values for all samples (65–91%) as normally required for self-bonding adhesion. Particleboard composites were then manufactured by thermopressing without any pretreatment or addition of synthetic binders. The properties of the resulting composites were assessed using bending test, internal bonding measurement, thickness swelling, water absorption and dynamical mechanical analysis. The fibrillum, leaflets and rachis based- composites have sufficient modulus of rupture to meet the Japanese Industrial Standard. However, only the fibrillum panels meet the French Standards. Furthermore, the results of dynamic mechanical analysis of leaflets composites reveal a relaxation peak which could be attributed to higher molecular weight carbohydrates. These preliminary results will allow to discriminate the various sources of fibrous particles on the same tree and to choose adequate preprocessing for further research.