The unique properties of the hottest polyurethane

2022-07-27
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The unique properties of polyurethane elastomers expand wide applications

characteristics of polyurethane elastomers

polyurethane elastomers are typical multiblock copolymers, and their molecular chains are composed of flexible segments whose glass transition temperature is lower than room temperature and rigid segments whose glass transition temperature is higher than room temperature. The oligomer polyol constitutes a flexible segment, and diisocyanate and small molecule chain extender constitute a rigid segment. The block structure of flexible and rigid segments determines the particularity of their performance, which is mainly reflected in:

(1) wide hardness range. The hardness range of ordinary rubber is generally in Sauer a, and the hardness range of plastic is about Sauer a95- Sauer D100. The elasticity of polyurethane is as low as Sauer A10 and as high as Sauer D85, and no filler is required. (2) High strength and elasticity. Polyurethane elastomer can still maintain high strength and elasticity in a wide range of hardness. (3) Excellent wear resistance, times that of natural rubber, known as "wear-resistant rubber". (4) Excellent water, grease and chemical resistance. (5) High impact resistance, fatigue resistance and vibration resistance, suitable for high-frequency flexure applications. (6) Good low temperature resistance. Low temperature brittleness is about -30 ℃ or below -70 ℃. (7) It has excellent heat preservation performance. Due to the low thermal conductivity, the thermal insulation effect is better than that of rubber and plastic. (8) Good biocompatibility and anticoagulant properties

in addition, these materials also have excellent electrical insulation, mold resistance and UV stability

there are various processing methods

polyurethane elastomers can be molded by the same processes as ordinary rubber, such as molding, mixing and vulcanization, or can be molded by pouring, centrifugal molding or spraying in the form of liquid rubber. They can also be made into granular materials and molded by injection, extrusion, calendering, blow molding and other processes

molded or cast products can also be processed again by mechanical means of semi-finished product turning. This semi-finished product turning processing method has become a more popular processing method in the industry in recent years. In particular, castable polyurethane elastomers, after mechanical pouring with elastomer pouring machine, use CNC machine tools to turn semi-finished products again. This process not only improves the working efficiency, but also greatly improves the dimensional accuracy and appearance of the product. Moreover, the use of pouring machine also avoids the hidden defects that may be caused by manual pouring, and greatly improves the service life of the product

a wide range of applications

due to many excellent characteristics of polyurethane elastomers, as well as flexible processing methods, polyurethane elastomers have been more and more applied to various industries in recent years, and the application fields are expanding day by day

1. The national defense industry

polyurethane elastomers are widely used in the national defense industry, such as airtight pads of various artillery, missile head protective covers, forward flow covers of aircraft, seat cushions in engine rooms and cabins, knee protection, aviation thin-wall oil tanks, inner membrane of aerospace drinking water tanks, helicopter rotor anti-corrosion film, aircraft landing gear buffers, bullet proof solid tires, anti-skid materials for tank armored vehicles, gun butts, military balloons, military cable sheaths Marine acoustic materials, potting parts and coatings for aviation and navigation electrical appliances, etc. In addition, polyurethane elastomers are also used in some seals in aerospace

northwest rubber and plastic research and Design Institute is currently developing a water storage container for aerospace, which is mainly used to store drinking water, ensure the water quality requirements of drinking water during the storage period, and can be used as a container for storing condensed water and human urine under system failure mode

combithermvpcxx-140, a multi-layer coextrusion composite film, is the international material of NASA emergency water bag liner. The test shows that this material has good compatibility with silver containing ionic water, and is also suitable for storing urine. However, this material is not suitable for containing iodine containing bactericide water because it can quickly absorb iodine. In addition, this material is processed from five kinds of materials, and organic carbon, mainly caprolactam, will be precipitated at the welded section

northwest rubber and plastic research and Design Institute selects thermoplastic polyurethane elastomer film material with excellent non-toxic and biocompatibility, which is processed by special welding process, and will not bring or release any toxic substances. The sample has passed the drinking water quality inspection and condensation. I hope it can bring help to everyone. The water phase is perpendicular to the plane of the leaf spring seat: the fulcrum is on the axis line of the 2 steering knuckle. The compatibility requirements of the pretreated urine residue after distillation

2. The light textile industry

polyurethane elastomers are also widely used in the light textile industry, including the use of textile cots, crimping wheels, speed increasing wheels, rotary wheels, printing and dyeing cots, chemical fiber pelletizing cots, fiber drawing cots, artificial leather, synthetic leather surface coatings and adhesives, shoe upper leather and sole, multi-purpose PU leather, soft foam mattresses, cushions, sofa mats, insulation layers of refrigerators Painting for decoration of high-grade furniture and light industrial products

3. Transportation

today's automobile technology is developing in the direction of high performance, low weight, comfort and safety. Rubber and plastic composites are gradually replacing metal materials, which opens up a very broad prospect for the application of polyurethane elastomers. Polyurethane elastomer materials are widely used in bumpers, steering wheels, cushions, back cushions, armrest door linings, spacer top plates, air bags, etc. In recent years, many businesses have turned to domestic sales of urethane composite tires in order to seek supply and demand for new green poly. There are also solid tires, wharf fenders, cold proof mats for passenger cars, sealing rings for locomotive oil tanks, and damping mats for train sleepers

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