Major Elastomers and Properties
Type	Isoprene	SBR	NEOPRENE	BUTYL	NITRILE	ETHYLENE
	Rubbers				COPOLYMERS	EPDM	EPM
	NR and IR
Specific Gravity………	1	0.9	1	1	1		1
Tensile Strength, psi
Pure Gum ……….	> 1000	< 500	> 3000	> 1500	> 500	< 400	< 300
Reinforced ……….	> 4000	> 3000	> 3000	> 2000	> 3000	> 3000	> 3000
Practical shore A
Hardness Range…	30-100	40-100	40-95	40-75	30-100	45-95	45-95
Resilience
Room Temperature …	E	G	G	P	F	G	G
Hot……………………	E	G	G	G	F	G	G
Tear Resistance………..	G-F	F	G	G	F	G	G
Abrasion Resistance…..	E	G-E	E	F-G	F	G-E	G-E
Atmospheric Aging Resistance…	P-E*	P-E*	E	F-G	F	G-E	G-E
Oxidation Resistance……..	G	G	G	G-E	F	E	E
Heat Resistance…………..	G	G	G	G-E	G	G-E	G-E
Low Temperature Flexibility…	E	G	F	F	F	G-E	G-E
Compression Set……………..	F-G	F	P(GN)	F	G	E	E
			G(W)
Permeability…………………..	F	F	G	E	E	F	F
Flame Resistance …………..	P-G*	P-G*	E	P	P	P-E*	P-E*
Acid Resistance
Dilute …………………….	G	F-G	E	E	G	E	E
Concentrated …………..	F	F-G	G	E	F	G	G
Moisture Resistance ……….	F-G	G-E	F	F	F	E	E
Solvent Resistance
Hydrocarbons   …………..	P	P	G**	P*	F	P	P
Oxygenated Solvents ……	G	G	P	G	P	G	G
				G**
Oil and Gasoline ………..	P	P	G	P*	E	P	P
Animal and Vegetable Oils	P-G	P-G	G	E	E	G	G
Dielectric Properties ………….	G-E	G	P	G-E	P	G-E	E