Group R
Rubbers > Group R
Group R | CR, IIR / BIIR / CIIR, HNBR, NBR / NBR-PVC, NR / IR, SBR, XNBR
CR (polychloroprene, neoprene)
Excellent mechanical properties, excellent resistance to abrasion, tearing and fatigue. Excellent resistance to UV radiation, ozone, oxygen, atmospheric agents, hot aging (but hardens due to prolonged heat in the presence of oxygen). Excellent resistance to seawater, salts, bases and diluted acids. Good flame resistance with self-extinguishing properties. Discrete or deficient dielectric properties, moderate resistance at low temperatures, high impermeability to many gases. Good resistance to minerals, silicone, animal and vegetable oils, aliphatic hydrocarbons and cooling fluids. It is not compatible with concentrated acids, aromatic and chlorinated hydrocarbons, polar solvents, ketones, esters and ethers, phenols, liquids of the HDF group. It is not possible to produce non-toxic items. Hardness 20 ÷ 90 Sh. Working temperature -20 +100 ° C (with peaks of 120 ° C). Glass transition temperature - 50ºC. Chloroprene tends to harden over time (especially at low temperatures), this is because it does form crystals in its macromolecules.
IIR (isobutene-isoprene-butyl copolymer) - BIIR (bromo-isobutene-isoprene-bromobutyl copolymer) - CIIR (chlorobutene-isoprene copolymer, chlorobutyl)
Very dense molecular structure, which guarantees a very high watertightness to air and water and to most gases. Perfect osmosis seal Good resistance to breakage and abrasion but low elastic performance. Good dielectric properties, excellent resistance to UV radiation, ozone, atmospheric agents, heat without flame resistance. Good compatibility with hot water, steam at 120 ° C, saline solutions, alkalis including medium / high concentration acids, hypochlorites, alcohols, ketones, glycols, vegetable and animal oils and fats. enough satisfactory compatibility with different ethers and esters, different types of Freon. It is not compatible with petroleum products in general, mineral oils and greases, aliphatic, aromatic and chlorinated hydrocarbons, non-polar fluids, synthetic lubricants based on ester. With the IIR it is possible to produce non-toxic articles. Hardness 40 ÷ 80 Sh. Working temperature -30 +110 ° C (-50 ° C +130/150 ° C with an optimal formulation).
HNBR (hydrogenated nitrile)
Characteristics: Exceptional mechanical value frame, exceptional resistance to abrasion, high resistance to permanent deformation (compression set), good aging and behavior at high temperatures. Chemical resistance to fats and mineral, animal, vegetable, silicone, hydraulic, aliphatic and aromatic hydrocarbons, chlorinated, polar solvents, oxygen, ozone, water, steam, gas, freon and their substitutes. It is possible to produce non-toxic items. Hardness 50 ÷ 90 Sh. Working temperature -40 +150 ° C.
NBR (acrylonitrile butadiene copolymer, nitrile rubber)
Good mechanical properties, low permanent deformation and good gas impermeability. Remarkable chemical resistance due to its saturated polymer chain. Excellent resistance in the presence of gas (methane, LPG, butane, propane). Good resistance to oils, minerals, animals, vegetables, silicon, hydraulic H, HL, H-LP, aliphatic hydrocarbons, non-polar solvents, non-flammable liquids HFA, HFB, HFC, hot water and saline solutions, fatty acids, acids and bases diluted. Good resistance to heat and aging (early age in hot air), low resistance to flames. Poor resistance to UV radiation, ozone and atmospheric agents, poor dielectric properties. It is not compatible with aromatic and chlorinated hydrocarbons, ketones, esters, phenols, polar solvents and concentrated acids. It can be non-toxic. Hardness 30 ÷ 95 Sh. Working temperature -40/30 +120 ° C (+100 ° C in air). To ensure greater durability of the NBR parts, it is recommended to avoid direct contact with air, using it in immersion applications or maintaining a protective layer of lubricating oil.
NR (natural polyisoprene, natural rubber) - IR (synthetic polyisoprene)
Excellent elastic performance and excellent resistance to wear and abrasion, cutting and tearing, exceptional elongation at break. It is possible to produce non-toxic items. Good dielectric properties, high resistance to cold, medium impermeability to gases. Good resistance to sea water, diluted acids and alkalis, alcohols and glycols. Poor resistance to UV radiation, ozone, oxygen, heat, nothing to the flames. It is absolutely incompatible with mineral, vegetable and animal oils, aliphatic, aromatic and chlorinated hydrocarbons, solvents (except acetone). Hardness 20 ÷ 70 Sh. Working temperature -70/60 +70/80 ° C. Glass transition temperature -70 / -75 ° C.
SBR (styrene butadiene copolymer)
Good mechanical properties, can have a good resistance to breakage, resistance to permanent deformation, elastic recovery and good resistance to fatigue, tear and wear. It is possible to produce non-toxic items. Good dielectric properties, compatible with silicone oils, water and diluted solutions of acids, bases and salts. Poor resistance to oxygen, ozone, UV radiation and oxidizing agents, except in appropriately formulated compounds. It is not compatible with mineral, vegetable and animal oils, aliphatic, aromatic and chlorinated hydrocarbons. Poor resistance to heat, nothing to the flame. Good resistance to cold. Hardness 40 ÷ 90 Sh. Working temperature -45 +100 ° C. Glass transition temperature -60ºC.
XNBR (carboxylated nitrile rubber)
Excellent mechanical value frame: high tensile strength, high resistance to tearing (also a hot one), very high resistance to abrasion. High adhesion and resistance to cohesion. Good chemical resistance in the presence. Of hydrocarbons, vegetable oils, water, steam, gas, acids and diluted bases. Good resistance to heat and aging, without resistance to flames. It is not possible to make non-toxic products. Especially suitable for covering wheels and rollers subject to high wear and high temperatures. Conditions of use impossible for polyurethane and too expensive for other elastomers. Hardness 65 ÷ 90 Sh. Working temperature -30 +145.