PU Polyether Rod (polyether polyurethane rod) is a thermosetting polyurethane rod synthesized with polyether polyol as soft segment, isocyanate (such as TDI, MDI) and chain extender as hard segment, and is formed by casting process. Compared with polyester polyurethane, the ether bond (-O-) in the molecular chain of polyether polyurethane gives it better hydrolysis resistance, low temperature toughness and resistance to microbial erosion, making it perform well in humid, cold or dynamic load environments. PU Polyether rods have a smooth and delicate surface (roughness Ra < 0.08μm) and uniform color (commonly brown, natural or black). The diameter range is usually 18mm to 350mm, and the length can be customized according to demand. According to the hardness grade and application requirements, it can be divided into high elasticity type (Shore A 70-90), high hardness type (Shore D 50-70) and high temperature resistant enhanced type (adding glass fiber or carbon fiber), etc., which are widely used in automotive sealing, medical equipment, industrial shock absorption and outdoor sports equipment.
Product performance
Mechanical properties
Super strong hydrolysis resistance: After long-term immersion in a high temperature and high humidity environment (85℃/85%RH), the strength retention rate is >90% (ordinary polyester polyurethane only retains 60%-70%), and the ether bonds in the molecular chain are not easily attacked by water molecules, which is suitable for parts that are in long-term contact with water (such as ship seals, swimming pool equipment).
Low temperature and high toughness: The brittle temperature is as low as -60℃ (ordinary polyester polyurethane is about -30℃), and it still maintains flexibility and impact resistance in extremely cold environments (such as -50℃ in the Arctic region), avoiding the material from becoming brittle and cracking (such as ski bindings that do not break brittlely at low temperatures).
High elasticity and fatigue resistance: Elongation at break is 500%-700% (ordinary polyester polyurethane is about 400%-600%), compression permanent deformation rate is <5% (ordinary polyester polyurethane>8%), and the deformation under long-term repeated compression load is small (such as car shock absorbers are used 50,000 times without collapse).
Thermal properties
Wide temperature range stability: long-term use temperature range -50℃ to 100℃ (ordinary polyester polyurethane is about -30℃ to 80℃), short-term resistance to high temperature of 120℃ (such as short-term overheating environment in the engine compartment of an automobile), heat deformation temperature (under 1.82MPa load) is about 90-110℃, and dimensional stability is better than ordinary polyurethane.
Low thermal expansion coefficient: about 7-9×10⁻⁵/℃ (close to metal), small deformation in temperature fluctuation environment (such as precision instrument parts maintain accuracy in temperature difference changes).
Chemical properties
Excellent hydrolysis resistance: no significant expansion or degradation (volume change rate <2%) after long-term immersion in distilled water, seawater, acid and alkali solution (pH 4-10), suitable for humid or corrosive environments such as ships and chemical storage tanks.
Resistant to microbial erosion: ether bond structure is not easily decomposed by microorganisms (ordinary polyester polyurethane is easily eroded by fungi and moldy), suitable for long-term outdoor exposure parts (such as sporting goods, agricultural equipment).
Moderate oil resistance: Good tolerance to mineral oil and silicone oil (volume change rate <3%), but slightly higher permeability to gasoline and diesel than polyester polyurethane (need to avoid long-term contact with fuel).
Electrical properties
Excellent insulation: Volume resistivity ≥10¹³Ω·cm, dielectric strength 20-28kV/mm, dielectric constant 3.0-3.2 (1MHz), suitable for low-voltage electrical components or electronic component packaging.
Processing performance
Casting process adaptability: Curing and molding through mold casting (curing time 6-12 hours), suitable for manufacturing complex-shaped parts (such as special-shaped seals, customized shock-absorbing blocks), and waste can be partially recycled (downgraded after crushing).
Surface treatment friendly: The surface can be sprayed with polyurethane coating or bonded (special glue is required), supporting customized appearance (such as anti-slip texture, matte coating).
Other characteristics
High transparency: Transparent PU Polyether rods have a light transmittance of ≥90% (haze <1%), suitable for optical instrument parts or transparent protective covers.
Lightweight: Density 1.05-1.15g/cm³ (slightly lower than polyester polyurethane), 70%-80% lighter than metal, suitable for weight-sensitive applications (such as drone parts).
Product Advantages
Extreme hydrolysis resistance
The ether bond structure of PU Polyether rods enables them to perform well in high temperature and high humidity environments, with a strength retention rate of >90%, making them an ideal choice for ships, swimming pools and chemical equipment. For example, in ship propeller seals, PU Polyether rods can resist long-term immersion in seawater, avoiding swelling and cracking caused by hydrolysis of traditional rubber seals; in pipe joint seals in hot spring baths, its high temperature and high humidity resistance ensures long-term stability of the sealing effect; in impeller sealing components of sewage treatment plants, PU Polyether rods resist microbial erosion in sewage and reduce maintenance frequency.
Ultra-low temperature toughness
The brittle temperature as low as -60°C enables PU Polyether rods to maintain flexibility and impact resistance in extremely cold environments, preventing the material from becoming brittle and cracking. For example, in the shock-absorbing pads of outdoor equipment at the Arctic research station, PU Polyether rods can still absorb vibration energy at -50℃ (impact strength retention rate>95%), ensuring stable operation of the equipment; in the binding pads of skis, its low-temperature toughness (elongation at break at -50℃>400%) prevents the binding from brittle cracking when skiers fall (service life>5 years); in the conveyor belt guide rails of the freezer, PU Polyether rods do not harden at -40℃ (friction coefficient is stable at 0.2-0.3), ensuring smooth food transportation.
High elasticity and fatigue resistance
The characteristics of elongation at break of 500%-700% and compression permanent deformation rate of <5% make PU Polyether rods perform well under long-term dynamic loads. For example, in automobile shock absorbers, its high elasticity (energy feedback rate > 75%) can absorb road impact energy (noise reduction of 15-20dB), and the compression permanent deformation rate < 5% ensures long-term use without collapse; in the joint buffer components of industrial manipulators, PU Polyether rods resist fatigue damage caused by high-frequency vibration; in the elastic bands of fitness equipment, its fatigue resistance provides stable resilience.
Resistance to microbial erosion
The ether bond structure gives PU Polyether rods excellent resistance to microbial erosion, which is suitable for long-term outdoor exposure parts. For example, in the shock-absorbing base of outdoor basketball stands, PU Polyether rods resist mold growth caused by rain and ultraviolet rays, and the service life is > 8 years (ordinary polyurethane is only 3-5 years); in the pipe seals of agricultural irrigation systems, its resistance to microorganisms prevents algae and bacteria from attaching, ensuring smooth water flow; in the protective cover of the ocean observation buoy, PU Polyether rods resist fungal erosion in seawater, ensuring long-term stable operation of the buoy.
Transparency and Lightweight
The light transmittance of transparent PU Polyether rods is ≥90% (haze <1%), and the density is 1.05-1.15g/cm³, making it an ideal material for optical instruments and drone parts. For example, in the protective cover of underwater cameras, its high transparency (light transmittance ≥95%) and hydrolysis resistance ensure clear underwater images (service life >2 years); in the shock-absorbing connector of drone blades, its lightweight characteristics (70% lighter than aluminum alloy) reduce flight energy consumption (endurance increased by 10%-15%), while high elasticity absorbs flight vibration (noise reduced by 10dB).
