Polymergroups

Polymer Groups
ASTM code	Description
NR, IR	The outstanding strength of natural rubber has maintained its position as the preferred material in many engineering applications. It has a long fatigue life and high strength even without reinforcing fillers. Other than for thin sections it can be used to approximately 100C, and sometimes above. It can maintain flexibility down to -60C if compounded for the purpose. It has good creep and stress relaxation resistance and is low cost. Its chief disadvantage is its poor oil resistance and its lack of resistance to oxygen and ozone, although these latter disadvantages can be ameliorated by chemical protection.
SBR, BR	This is the highest volume general purpose synthetic rubber. It is very weak unless reinforcing fillers are incorporated. With suitable fillers it is a strong rubber although not approaching natural rubber of polychloroprene. Otherwise it has similar chemical and physical properties to natural rubber, with generally better abrasion resistance but poorer fatigue resistance.
CR	Polychloroprene-or Neoprene® rubber has a generally good balance of mechanical properties and fatigue resistance second only to natural rubber, but with superior chemical, oil, and heat resistance. It is widely used in general engineering applications. It is less resistant than natural rubber to low temperature stiffening but can be compounded to give improved low temperature resistance. It has good ozone resistance. It is suitable for use with mineral oils and greases and dilute acids and alkalis, but is unsuitable in contact with fuels. It has generally poorer set and creep than natural rubber.
CSM	Chlorsulfonated Polyethylene (Hypalon®) is a material with ‘polychloroprene (Neoprene®) plus’ qualities. It is suitable for continuous use up to about 130C and intermittent use up to some 30C above this. It has excellent resistance to oxygen, ozone and most chemicals, including water, but has poor fuel resistance. It has low gas permeability. It has poor compression set resistance which limits its usefullness in dynamic sealing applications.
CM	Chlorinated Polyethylene has good chemical resistance to hydrocarbon fluids and elevated temperatures. Used for hose linings. Poor mechanical strength. Mechanical properties may deteriorate above 100C
EP(D)M	Ethylene-Propylene-(Diene) rubber is the most water resistant rubber available, and this resistance is maintained to high temperatures (up to 180C in steam for peroxide cures). The highest temperature resistance is achieved by using peroxide cured grades. Has excellent resistance to atmospheric ageing, oxygen and ozone up to about 150C. It has good resistance to most water-based chemicals and to vegetable-based hydraulic oils. But it has very poor resistance to mineral oils and di-ester based lubricants.
NBR	Nitrile rubber is at temperatures up to 100C, or with special compounding up to 120C, an economic material having a high resistance to aliphatic hydrocarbon oils and fuels. Different grades are available - the higher the acrylonitrile (ACN) content, the higher the oil reisistance but the poorer is the low temperature flexibility. It has high resilience and high wear resistance but only moderate strength. It has limited weathering resistance, and poor aromatic oil resistance. It can generally be used down to about -30C, but special grades can operate at lower temperatures.
HNBR	Hydrogenated nitrile rubber provides good all round performance at a compound cost between Nitrile and Fluoroelastomer. Its highly saturated main chain provides good resistance against thermal oxidation up to 150 C and chemical attack. It has good physical properties, including abrasion resistance, at high temperatures, good dynamic behaviour and flex cracking resistance at elevated temperatures. Excellent heat, ageing and ozone resistance and outstanding resistance to steam and hot water. Limitations are no inherent flame retardency, poor electrical properties, unsuitable in contacts with aromatic and polar organic solvents.
XNBR	Carboxylated Nitrile rubber. A way to increase the strength, especially the abrasion resistance of Nitrile rubber is to carboxylate the polymer. XNBR competes directly against Polyurethane rubber. The material is resistant to water , alcohols, parafinic hydrocarbons and aliphatic type chemicals. It resists temperatures up to 135 C.
MVQ	Siliconerubbers show excellent low temperature properties, They have aService temperature -80C to 260C Excellent ozone resistance. Excellent resistance to oxidation. Very good water resistance.Can also be used with a platinum cure system instead of a peroxide system. Characterized by exceptionally high tear strength and tight surface cure
MFQ,FVMQ	Fluorosiliconerubbers based on a fluorine containing polymer giving the material excellent resistance to many fuels and chemicals which would severely degrade silicone and most other polymers. Has low temperature characteristics similar to that of general purpose silicones compounds.Can also be used with a platinum cure system instead of a peroxide system. Characterized by exceptionally high tear strength and tight surface cure.
AU, EU	Polyurethanerubbers have high tear strength and good wear resistance. Their upper temperature limit is typically 80C. They have excellent resistance to weathering and oxidation. They resist hydrocarbon fuels and mineral oils but some grades hydrolyse in hot water. They are one of the best elastomers for abrasion resistance and are therfore used in reciprocating seals. Some grades are castable.
FPM	Fluorocarbons (Viton®) This is a family of elastomers designed for very high temperature operation. They can operate continuously somewhat in excess of 200C depending on the grade, and intermittently to temperatures as high as 300C. They have outstanding resistance to chemical attack by oxidation, by acids and by fuels. They have good oil resistance. However, at the high operating temperatures they are weak, so that any design must provide adequate support against applied forces. They have limited resistance to steam, hot water, methanol, and other highly polar fluids. They are attacked by amines, strong alkalis and many Freons. There are standard and special grades - the latter can be compounded by us to have special properties such as improved low-temperature resistance.
ACM/EAM	(Ethylen) Acrylic rubber (Vamac®) has better low temperature performance (to -40C) and dynamic properties than acrylic (qv), but at the expense of fluid resistance. It has good compression set resistance, but poor resistance to aromatic hydrocarbons, strong acids and bases.
CO, ECO, ETER	Epichlorhydrinerubber has high resistance to ageing, oxidation, ozone, and hot oil. Good resistance to hydrocarbon solvents, Special compounding can result in very good low temperature flexibility (Tg -40C). Poor abrasion resistance and electrical properties
(C) (B) IIR	(Halogenated) Butylerubber has very high impermeability to gases and is hence used for the inner tubes of pneumatic tyres, and in vacuum and high pressure applications. It has an unusually broad loss peak so that, despite having a glass transition temperature as low as -65C, it displays high damping at ambient temperatures It has good ozone, weathering, heat, and chemical resistance. Not suitable for use in contact with mineral oils.