Polyurethane elastomers belong to block polymers, that is, polyurethane macromolecules are composed of “soft segments” and “hard segments” and form a micro phase separation structure. The hard segments (derived from isocyanates and chain extenders) are dispersed in the soft segment phase region (derived from oligomer polyols) and play the role of physical crosslinking points. Therefore, compared with other synthetic rubber (elastomers), polyurethane elastomers have better strength and wear resistance, High elongation can still be maintained when the hardness is high.
Elastic polyurethane materials, referred to as “case” in foreign countries, mainly include traditional polyurethane elastomer products, polyurethane plastic runway and other pavement materials, polyurethane waterproof coatings, adhesives, sealants, potting adhesives, etc., accounting for about 40% of the total amount of polyurethane products. Most of the cured products of case materials (water-based and solvent-based products remove water and solvents) are non foam elastic polyurethane materials. PU synthetic leather resin, some coatings and adhesives are solvent-based or aqueous products, which can also be regarded as polyurethane elastomer materials in a broad sense. In a narrow sense, polyurethane elastomer refers to cast polyurethane elastomer (CPU), thermoplastic polyurethane elastomer (TPU) and mixed polyurethane elastomer (MPU), accounting for 10% or slightly less of the total polyurethane. CPU and TPU are the main polyurethane elastomers, and their differences lie in factors such as production process and chain extender. This kind of traditional polyurethane elastomer, also known as “polyurethane rubber”, belongs to a kind of special synthetic rubber. High performance polyurethane elastomer is the material with the best wear resistance among all synthetic polymer materials. It is known as the “king of wear resistance”. It is widely used in many fields, and new applications are still expanding.
Polyurethane elastomers can be used to replace metals, plastics and ordinary rubber in some fields.
Compared with metal materials, polyurethane elastomer has the advantages of light weight, low noise, loss resistance, low processing cost and acid corrosion resistance. Compared with plastics, it has the advantages of high toughness and high wear resistance. Compared with ordinary rubber, polyurethane elastomer has the advantages of wear resistance, cutting resistance, tear resistance, high bearing capacity, ozone resistance, simple manufacture, potting and pouring, and wide hardness range.
Polyurethane elastomer is an important variety of polyurethane. At present, its consumption accounts for nearly 10% of the total consumption of polyurethane. Polyurethane elastomer is used to manufacture all kinds of rubber wheels, conveyor belts, water-resistant and pressure resistant rubber hoses, sealing strips and rings, cable sheaths and various films. The products are widely used in iron and steel, papermaking, mining, machinery, printing and other industries. Polyurethane elastomer can be modified by other polymers, fibers, powder fillers, etc. to reduce cost and improve performance.
Post time: May-05-2022
