Points for attention in polyurethane experiment

Characteristics of polyurethane materials

Polyurethane PU materials are widely used in various parts of national economy and industrial production, and can be seen everywhere in daily life. Polyurethane is one of the most cost-effective thermal insulation materials in the world. It is widely used in furniture, household appliances, equipment, transportation, sports, shoe and leather industry. Polyurethane rigid foam is mainly used in equipment industry, such as external wall insulation board, refrigeration equipment and cold storage insulation material, pipeline insulation material, sealant, waterproof coating, etc. In Europe and America, polyurethane rigid foam for equipment accounts for about 70% of the total consumption of rigid foam. In China, the application of hard foam in equipment industry is not as widespread as that in western countries, so it has great potential for development. In recent years, rigid polyurethane foam has been gradually applied in door and window profiles, and has achieved excellent performance in heat insulation, which makes it play an important role in the energy-saving platform of doors and windows.

The general characteristics of polyurethane "polyurethane" is the abbreviation of polyurethane, the English name is polyurethane, the English abbreviation is Pu or pur. It is an organic polymer material, known as "the fifth largest plastic". Polyurethane was invented in Germany in 1937. It is made of isocyanate (monomer) and hydroxyl compound (polyether type or polyester type) in a certain proportion. Pu has many excellent properties, including:

Wide adjustable range and strong adaptability; Good wear resistance; High mechanical strength; Good adhesion; It has good elasticity and excellent restorability, and can be used for dynamic seam; Good flexibility at low temperature; Good weather resistance and long service life; Good oil resistance; High hydrophobicity.

Polyurethanes are mainly made of isocyanate, polyether and polyester polyols. Under the action of foaming agent, catalyst, flame retardant and other additives, they are mixed by special equipment and foamed under high pressure to form high molecular polymers, which are mainly divided into flexible PU, rigid PU and PU elastomers.

Polyurethane foaming material is a kind of high molecular polymer, which is made of isocyanate, polyether and polyester polyol as main raw materials, mixed by special equipment under the action of foaming agent, catalyst, flame retardant and other additives, and foamed under high pressure.

The polyurethane soft foam has the characteristics of low density, good elastic recovery, sound absorption, air permeability, heat preservation and so on. Its main function is buffering. It is very suitable to be used as a cushion material. The cushion material is also an application platform with large amount of soft foam, such as mattresses, sofas, seats and pillows; At the same time, polyurethane foam is also an ideal sound-absorbing material, which can be used to make sound-absorbing cotton.

Rigid polyurethane foam is a kind of thermosetting plastic, with closed cell layout, heat preservation and waterproof functions; The low thermal conductivity is 0.022 ~ 0.1W / (m)· Κ) Equivalent to half of the extruded board, is the current all the same grade of thermal insulation materials with low thermal conductivity. Polyurethane rigid foam is mainly used in equipment industry, such as external wall insulation board, refrigeration equipment and cold storage insulation materials, pipeline insulation materials, etc.