Thermal Properties

COMPARATIVE PHYSICAL PROPERTIES OF RUBBER
TYPE NATURAL RUBBER STYRENE BUTADIENE BUTYL NITRILE NEOPRENE SILICONE FLUOROCARBON HYDRIN EPDM PENTATHANE
ASTM Designation NR SBR IIR NBR CR VMQ FKM CO, ECO EPM, EPDM AU, EU
PHYSICAL PROPERTIES                    
Specific Gravity 0.92-0.93 0.94 0.92 0.98 1.23-1.25 1.1-1.6 1.4-1.95 1.27-1.49 0.86 1.02-1.20
Thermal Conductivity 0.082 0.143 0.053 0.143 0.11 0.13 0.06-1.3 - 0.15 0.09-0.10
Btu/ft/hr/sq ft/F 37 37 32 39 34 45 - - 32 -
Coef of Ther Exp (cubical) 10^-5 per F Gum                    
MECHANICAL PROPERTIES                    
Hardness, Durometer 30A-90A 30A-90A 30A-95A 30A-95A 90A-95A 20A-90A 55A-95A 30A-95A 30A-90A 10A-80D
Tensile Strength 1000 psi 3.5-4.5 2.5-3.0 2.0 1.0-3.5 0.5-3.5 1.5 2.0 2-3 0.5-3.5 .08-8.0
Modulus (100%), psi 150-3000 300-1500 50-500 100-1500 100-3000 - 200-2000 150-2000 100-3000 25-5000
Elongation, % 500-700 450-500 300-800 400-600 100-800 100-800 150-450 320-350 100-700 250-800
Compression Set, Method B, % 10-30 5-30 25 5-20 20-60 10 20-25 20 20-60 0.7-45
Resilience (ASTM 945) % 80 20-90 30 - 50-80 30-60 40-70 50-80 40-75 5-75
Rebound (Bashore) - 10-60 - - 50-80 - 40-70 50-80 40-75 20-65
Hysteresis Resistance Excellent Fair-Good - - Very Good Fair-Good Good Good Good Fair-Good
Flex Cracking Resistance Excellent Good - Fair-Good Very Good Fair-Excellent Good Very Good Very Good Excellent
Tear Resistance Excellent Fair Good Good Good Fair Fair-Very Good Very Good Fair-Good Outstanding
Abrasion Resistance Excellent Excellent Good Excellent Excellent Poor Good Fair-Good Good-Excellent Outstanding
Impact Resistance Excellent Excellent Good Good Excellent Poor-Good Good Good Very Good Outstanding
ELECTRICAL PROPERTIES                    
Volume Resistivity, ohm-cm - 5.0-8.4 x 10^8 2.0 x 10^16 3.5 x 10^10 2.0 x 10^13 1 x 10^14 - 1 x 10^16 2 x 10^13 - 2 x 10^16 - 1 x 10^17 0.3 x 10^10 - 4.7 x 10^13
Dielectric Strength 400-600 600-800 600-900 250 400-600 400-700 500 - 500-1000 330-700
THERMAL PROPERTIES                    
Service Temperature, F                    
Min for Continuous Use -70 -65 -50 -65 -60 -178 -40 -50 -70 -65
Max for Continuous Use 250 225 300 250 225 600 550 275 350 200
Heat Aging at 212F B-C B A B B-A A A B-A B-A B
ENVIRONMENTAL RESISTANCE                    
Ozone Poor Poor Excellent Poor Very Good Excellent Outstanding Excellent Outstanding Excellent
Oxidation Good Good Excellent Fair-Good Very Good Excellent Outstanding Excellent Excellent Excellent
Weathering Fair Fair Excellent Good Very Good Excellent Excellent Excellent Outstanding Good
Water Excellent Excellent Excellent Excellent Good Excellent Good Good Excellent Good-Excellent
Radiation Fair-Good Good Poor Fair-Good Good Fair-Good Fair-Good Poor Good Good-Excellent