PARTICLEBOARDS FROM RENEWABLE RESOURCES

R.A. RUSECKAITE; E.M. CIANNAMEA; P. LEIVA; P.M. STEFANI

San Sebastian, España

Congreso; MoDeSt 2006; 2006

CSIC, UPV-EHU

Particleboards are wood products, made mainly of small chips of timber, lumber, and wood.Particleboards are used in many places in our daily life, such as frames of integrated kitchen system and subflooring. Nowadays, lignocellulosic agricultural residues are been considered as potential substitutes to replace natural wood in the panel industry. Bio-based resources are renewable, widely distributed, available locally, recyclable and biodegradable. Rice husk (RH) is a by-product of rice milling process and a great resource of raw biomass material for manufacturing value-added composite products. It has the same basic components as wood: cellulose(25-35 wt.%), hemicelluloses (18-21wt.%), lignin (26-31wt.%), waxes, amorphous silica (15-17wt%), absorbed moisture (8-11wt.%) and water soluble substances (2-5wt.%). On the other side, more than 90% of particleboards are bonded with urea – formaldehyde (UF) or phenol – formaldehyde (PF) resins, because they provide durable bonds and at low costs. In addition to the possible environmental problem resulted from the toxic formaldehyde emissions, these resins have poor bondability with materials such as rice husk. The inherent nonpolar characteristic of the RH surface (due to the presence of waxes and silica) is not compatible with the polar nature of PF and UF resins. Soy proteins (SP) have been used to replace UF and PF to reduce emissions and to overcame bonding problems. Therefore, the idea of the present work is to produce environmentally sound particleboards based on rice husk and soy protein concentrate (SPC) adhesives. For comparing purposes, commercially available UF and PF resins are used in order to evaluate the final properties of the materials, particularly their durability.