Polyurethane is the general name for polymers composed of urethane bond . Polyurethanes are formed by reacting a polyol with a di- or tri poly-isocyanate . Properties of polyurethane depend on original reactants structure, can produce a broad range of materials for specific applications. They exist in various forms such as rigid foams, flexible foams, elastomers, adhesives, coatings, paints, etc. Properties including low weight, flexibility, high adhesion to various surfaces, excellent thermal insulation, soundproofing, high resistance to UV and atmospheric conditions have increased use of these materials.
Foams are a common use of polyurethanes, can be obtained in rigid form to rubbery form at any density. They are used in many applications such as thermal insulation and production of blocks and panels. A type of rigid polyurethanes are ideal for insulation of refrigerating appliances and help reduce energy consumption.
Wood imitation rigid polyurethane foam is a new category of material, expanding as substitute for natural wood. Their appearance and feel close to wood which could be planed nailed, drilled and carved patterns or designs . Compared with natural wood, PU wood imitation has more lower weight, fire resistance, corrosion and water resistance and lower cost.