FINISHING PROPERTIES OF RUBBERWOOD (Hevea brasiliensis) COATED WITH BIO-BASED POLYURETHANE

Abstract

Most of the polyols that are used in our daily life have been synthesized from petroleum resources. Petroleum-based materials are not easily decomposed by microorganisms, and this can lead to various environmental problems when the life cycle of these products has been achieved. Another problem of these petroleum-based materials is because of continuous increasing of petroleum price. As the price of petroleum has increased, the price of polyurethane (PU) has also affected. A study was carried out to synthesize PU with properties suitable for wood finishing. The PU was prepared by reacting rubberwood polyols with toluene-2, 4-diisocyanate (TDI) and 2-ethylhexyl acrylate (EHA). The bio-based PU was applied to rubberwood surface and the finished surface was tested for impact and adhesion strengths. Two parameters were studied; coating formulations (Formulation A, B, C, and D) and number of coats (2-layer and 3-layer). The results show that properties of the coated surface were influenced by both of the formulation and number of coats. Meanwhile, the amount of finish uptake was highly significant with the number of coats, but not with the coating formulation. Overall, coating using Formulation A, B, and C in two layers (1 undercoat + 1 top coat) produced good impact and adhesion surface. It is clear that the finishing (physical) properties of bio-based PU produced in this study had shown good potential as a wood coating material.