Here’s an overview of common rubber materials, categorized by type and described:
Natural Rubber (NR):
Source: Derived from the latex of the Hevea brasiliensis tree.
Key Properties: Excellent elasticity, high tensile strength, good tear resistance, low hysteresis (good resilience), low heat build-up, good abrasion resistance. Poor resistance to oils, fuels, ozone, and weathering. Good low-temperature flexibility.
Common Applications: Tires, engine mounts, seals, hoses, conveyor belts, footwear, adhesives, gloves.
Styrene-Butadiene Rubber (SBR):
Source: Synthetic copolymer of styrene and butadiene.
Key Properties: Good abrasion resistance, good aging stability (with antioxidants), moderate strength. Generally inferior elasticity, tensile strength, and resilience compared to NR. Poor oil/fuel resistance. Better ozone/weathering resistance than NR.
Common Applications: Tire treads (often blended with NR), shoe soles, gaskets, conveyor belts, hoses, flooring, adhesives.
Polybutadiene Rubber (BR):
Source: Synthetic polymer of butadiene.
Key Properties: Excellent resilience, excellent low-temperature flexibility, good abrasion resistance. Low hysteresis (low heat build-up). Poor tear strength and tensile strength. Poor resistance to oils, ozone, and weathering.
Common Applications: Primarily blended with NR and SBR in tire treads and sidewalls to improve resilience and low-temperature performance. Golf ball cores, footwear soles.
Nitrile Rubber (NBR) / Acrylonitrile Butadiene Rubber:
Source: Synthetic copolymer of acrylonitrile (ACN) and butadiene.
Key Properties: Excellent resistance to oils, fuels, and greases. Resistance increases with higher ACN content. Good abrasion resistance, good compression set resistance. Poor ozone/weathering resistance. Low-temperature flexibility decreases with higher ACN content.
Common Applications: Oil seals, fuel hoses, O-rings, gaskets, diaphragms, printing rolls, hydraulic equipment parts, gloves.
Chloroprene Rubber (CR) / Neoprene:
Source: Synthetic polymer of chloroprene.
Key Properties: Good resistance to oils, ozone, weathering, and moderate heat. Good flame retardancy. Moderate resistance to chemicals and aging. Good physical toughness and resilience. Better oil resistance than NR/SBR, less than NBR.
Common Applications: Hoses, belts, seals, gaskets, weatherstripping, cable jackets, wetsuits, adhesives, coated fabrics, vibration mounts.
Ethylene Propylene Diene Monomer (EPDM):
Source: Synthetic terpolymer of ethylene, propylene, and a small amount of diene monomer (for crosslinking).
Key Properties: Excellent resistance to ozone, weathering, heat, water/steam, and polar chemicals (e.g., brake fluids, detergents, glycols). Very good electrical insulation properties. Poor resistance to petroleum oils and fuels. Good low-temperature flexibility.
Common Applications: Automotive weatherstripping, radiator/heater hoses, seals, roofing membranes, wire & cable insulation, appliance parts, garden hoses.
Butyl Rubber (IIR):
Source: Synthetic copolymer of isobutylene and small amounts of isoprene.
Key Properties: Extremely low air permeability (best among rubbers). Excellent resistance to ozone, weathering, heat aging, and flex cracking. Good chemical resistance (acids, alkalis), good vibration damping. Poor resistance to oils and fuels. Slow cure rates.
Common Applications: Tire inner liners (tubes/tubeless), pharmaceutical stoppers, vibration isolators, shock absorbers, hoses for chemicals, sealants, tank linings.
Silicone Rubber (Q, SI, VMQ, PVMQ, FVMQ):
Source: Synthetic polymers based on silicon-oxygen backbone with organic side groups.
Key Properties: Excellent high-temperature resistance (up to 300°C/572°F or higher for specialty grades) and low-temperature flexibility (down to -100°C/-148°F). Excellent resistance to ozone and weathering. Good electrical insulation. Low toxicity. Poor tensile strength, tear strength, and abrasion resistance compared to organic rubbers. Poor resistance to oils, fuels, solvents, and acids/bases. Can be biocompatible.
Common Applications: High/low temperature seals & gaskets, O-rings, medical devices, implants, tubing, baby bottle nipples, bakeware, keypads, electrical insulation, automotive components.
Fluoroelastomer (FKM, FPM):
Source: Synthetic copolymers containing fluorine, often vinylidene fluoride (VDF) and hexafluoropropylene (HFP).
Key Properties: Outstanding resistance to high temperatures (up to 250°C/482°F), oils, fuels, ozone, weathering, and a wide range of aggressive chemicals and solvents. Low gas permeability. Relatively poor low-temperature flexibility and resistance to some polar solvents (e.g., ketones, esters) and steam. Higher cost.
Common Applications: Critical seals, O-rings, gaskets, hoses, diaphragms in aerospace, automotive (fuel systems, engines), chemical processing, oil & gas exploration, and semiconductor manufacturing.
Chlorosulfonated Polyethylene (CSM) / Hypalon:
Source: Synthetic rubber made by chlorinating and chlorosulfonating polyethylene.
Key Properties: Excellent resistance to ozone, weathering, oxidation, and chemicals (acids, alkalis). Good heat resistance and flame retardancy. Moderate oil/fuel resistance. Good colorability. Can be difficult to process.
Common Applications: Roofing membranes, geomembranes, tank linings, wire & cable insulation, pond liners, coated fabrics, hoses.
Polyacrylate Rubber (ACM):
Source: Synthetic polymers based mainly on acrylate esters.
Key Properties: Excellent resistance to hot oils and lubricants (better than NBR at higher temperatures). Good resistance to ozone and weathering. Poor resistance to hot water/steam, low temperatures, and acids/bases.
Common Applications: Automotive transmission seals, valve stem seals, O-rings, gaskets exposed to hot oils.
Epichlorohydrin Rubber (CO, ECO, GECO):
Source: Synthetic polymers based on epichlorohydrin (CO), copolymer with ethylene oxide (ECO), or terpolymer (GECO).
Key Properties: Excellent resistance to fuels, oils, ozone, weathering, and low gas permeability. Good heat resistance. Good dynamic properties. Poor resistance to polar solvents and acids/bases.
Common Applications: Fuel hoses, seals, gaskets, diaphragms, and O-rings in automotive fuel systems, vacuum systems, and air conditioning systems.
Thermoplastic Elastomers (TPE): Note: TPEs are polymeric materials exhibiting elastomeric properties but process like thermoplastics.
Types: Include Styrenic Block Copolymers (TPS – e.g., SBS, SEBS), Thermoplastic Polyolefin Elastomers (TPO), Thermoplastic Vulcanizates (TPV – e.g., EPDM/PP), Thermoplastic Polyurethanes (TPU), Thermoplastic Copolyester Elastomers (TPC), Thermoplastic Polyamide Elastomers (TPA).
Key Properties: Processability like plastics (molding, extrusion), recyclable, wide range of hardnesses and properties depending on type. Generally lower heat resistance and compression set than thermoset rubbers, but constantly improving. Can combine flexibility with strength/abrasion resistance (TPU).
Common Applications: Vast range: automotive trim, grips, seals, hoses, medical tubing, cable sheathing, sporting goods, footwear, consumer goods, overmolding.
This list covers the major categories, though many specialty and blended rubbers exist to meet specific performance requirements.
