Polyurethane ( PU, AU, EU )

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14 Nov 2022

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PU, AU, EU

Polyurethane ( PU, AU, EU )

The millable Polyurethane rubbers are distinguished into two types; one is polyester urethane (AU), the other is polyether urethane ( EU ). AU type urethanes have outstanding oil, fuel and solvent resistance but can be attacked by hydrolysis, EU type urethanes are not attacked by hydrolysis and still offer a fuel and oil resistance comparable to low ACN ( 18~22% ACN ) Nitriles or HNBRs. Any type polyurethane has excellent wear resistance, high tensile strength and high elasticity in comparison with any other elastomers. We also can offer any type thermoplastic urethane ( TPU ).

Cure system – Peroxide – Cured

Standard PU compounds are peroxide-cured.

Other Common Variations:

►Polyurethane usually is applied in mechanical industry, especially in the place where material must have higher wear resistance and higher strength.

►In some applying environment, moisture condensing will happen on the surface of rubber seal, and this will cause hydrolysis of AU so choosing EU is better. But EU does not resist oil very well, thus higher aniline point oil must be used for lubricant application.

►Appling in hydraulic system, TPU will be better than millable Polyurethane

Performs Well In…

►Aliphatic hydrocarbon

►Mineral oil and grease

►Silicone oil and grease

►Ozone

►Water up to 50°C ( EU type )

Doesn’t Perform Well In…

►Ketones

►Alcohols

►Esters

►Ethers

►Hot water and steam

►Alkalis, amines

►Acids

►Glycols

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admin_ilkhani

14 Nov 2022

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Carboxylated Nitrile ( XNBR )

XNBR Carboxylated Nitrile ( XNBR ) Cabboxylated Nitrile is similar to Nitrile rubber, but the polymer backbone has been chemically modified with Carboxylic Acid containing group. This result is XNBR with more excellent abrasion and tear resistance than traditional NBR. For this reason, XNBR based parts are usually applied in dynamic assembly such as seals and rod wipers. Cure system - Sulfur - Cured Standard XNBR compounds are sulfur-cured Performs Well In… ►Aliphatic hydrocarbon ►Vegetable and mineral oils and greases ►Diesel ►Water Dilute acids, alkali and salt solutions Doesn't Perform Well ...

admin_ilkhani

14 Nov 2022

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Silicone Rubber ( MQ, VMQ, PVMQ )

VMQ Silicone Rubber ( MQ, VMQ, PVMQ ) Physically, silicones are based on silicon, an element derived from quartz. To create this class of synthetic elastomers, pendant organic groups such as methyl, phenyl and vinyl are attached to silicon atoms. The different addition of side chains can achieve significant variations in properties. Silicones have excellent heat, ozone and corona resistance, very well dielectric stability, and resistance to many oils, chemicals, and solvents. And for all elastomers, silicones possess the best flexible property ...