"Polyurethane" is the abbreviation of polyurethane. It is an organic polymer material, known as the "fifth largest plastic".
PU has many features, including:
(1) Wide range of performance adjustment and strong adaptability;
(2) Good wear resistance;
(3) High mechanical strength;
(4) Good adhesion;
(5) High hydrophobicity;
(6) Low temperature flexibility;
(7) Good weather resistance and long service life;
(8) Good oil resistance;
(9) With good elasticity and resilience, it can be used for dynamic joints.
With isocyanate, polyether, polyester polyol as the main raw materials, polyurethane foams under high pressure after being mixed by special equipment under the action of foaming agent, catalyst, flame retardant and other additives. It is mainly divided into flexible PU, rigid PU and PU elastomer.
Polyurethane foam material
Polyurethane foaming material is a kind of high polymer foamed under high pressure by using isocyanate, polyether and polyester polyol as main raw materials, mixing them with special equipment, and using foaming agent, catalyst, flame retardant and other additives.
Polyurethane soft foam
Polyurethane soft foam is an open cell structure with low density, good elastic recovery, sound absorption, air permeability, thermal insulation and other properties. Its main function is buffering, which is very suitable for use as a buffer material. Cushion materials are also the application fields with large amount of soft foam, such as mattresses, sofas, chairs, pillows, etc; At the same time, polyurethane soft foam is also an ideal sound absorption material, which can be used to make sound absorption cotton.
Polyurethane rigid foam
Polyurethane rigid foam is a thermosetting plastic with closed cell structure, which has the function of heat preservation and waterproof; Low thermal conductivity is 0.022~0.1W/(m· Κ)， It is equivalent to half of the extruded board, and the thermal conductivity of all thermal insulation materials in the same layer is low. Polyurethane rigid foam is mainly used in the construction industry, such as external wall insulation board, refrigeration equipment and cold storage insulation materials, pipeline insulation materials, etc.
Polyurethane elastomer
Polyurethane elastomers are also widely used, from machine parts to tires, from waterproof materials and tapes to synthetic leather and polyester fibers. Mainly divided into:
Cast polyurethane elastomer (CPU)
CPU is one of the polyurethane elastomers widely used and produced, accounting for about 65% of the total polyurethane elastomers. CPU is easy to form. The liquid reactants are injected into the mold and can be solidified into products with complex shapes after heating. It is suitable for manufacturing large products. It is widely used in synthetic leather, pavement waterproof materials, sports track, building waterproof materials, etc. At present, this material is commonly used for casting bridge truncated aluminum door and window profiles of bridge truncated filling part.
Thermoplastic polyurethane elastomer (TPU)
TPU, also known as thermoplastic polyurethane rubber, accounts for about 25% of the total polyurethane elastomer. It can be plasticized by heating and dissolved by solvent. It has excellent comprehensive properties such as high strength, high toughness, wear resistance and oil resistance. It has good processing performance and is widely used in national defense, medical treatment, clothing, food and other industries. It can be made into polyurethane fibers, insoles, sports equipment, wire and cable sheaths, fire clothing, toys, film covering materials, etc.
Mixed polyurethane elastomer (MPU)
MPU, also known as mixed polyurethane rubber, accounts for about 10% of the total polyurethane elastomer. It has high mechanical strength, excellent chemical resistance and oil resistance. MPU is widely used in mechanical field and plays a stable role in humid and hot environment and oily environment. Make rubber roller, seal ring, oil seal, bearing, bushing and other mechanical parts.
Polyurethane is widely used in many fields due to its high physical and mechanical properties, high wear resistance, oil resistance, low temperature resistance and wide hardness range.
