Urethane produced parts will in most cases outperform natural and synthetic rubbers. The composition and materials of urethane are of higher grades and are able to withstand a much broader range of extreme properties. It is important to remember that urethane can be more expensive in material costs but less expensive to manufacture. Urethane will in most cases outlast natural and synthetic rubbers and that should be taken into consideration when purchasing high quality urethane products from Acrotech Inc.
PROPERTIES | NATURAL RUBBER | SBR or BUNA S | BUTYL | NITRILE (BUNA N) | NEOPRENE | URETHANE | |
butadiene styrene | isobutylene isoprene | butadiene acrylonitrile | chloroprene | ||||
Tensile Strength, (PSI) Pure Gum | Over 3000 | Below 1000 | Over 1500 | Below 1000 | Over 3000 | 1000 – 10,000 | |
Hardness Range (Durometer A) | 30-90 | 40-90 | 40-75 | 40-95 | 40-95 | 33-95 + (75 shore D) | |
Specific Gravity (base material) | 0.93 | 0.94 | 0.92 | 1.00 | 1.23 | 1.10 | |
Vulcanizing Properties | Excellent | Excellent | Good | Excellent | Excellent | Excellent | |
Adhesion to Metals | Excellent | Excellent | Good | Excellent | Excellent | Excellent | |
Adhesion to Fabrics | Excellent | Good | Good | Good | Excellent | Excellent | |
Tear Resistance | Good | Fair | Good | Fair | Good | Outstanding | |
Abrasion Resistance | Excellent | Good to Excellent | Good | Good | Excellent | Outstanding | |
Compression Set | Good | Good | Fair | Good | Fair to Good | Good | |
Compression Set Cold | Excellent | Good | Bad | Good | Very Good | Fair | |
Rebound Hot | Excellent | Good | Very Good | Good | Very Good | Good | |
Electric Strength | Excellent | Excellent | Excellent | Poor | Good | Excellent | |
Electrical Insulation | Good to Excellent | Good to Excellent | Good to Excellent | Poor | Fair to Good | Fair to Good | |
Permeablity to Gases | Fair | Fair | Very Low | Fair | Low | Fair to Good | |
Acid Resistance: | Dilute | Fair to Good | Fair | Excellent | Good | Excellent | Fair to Good |
Concentrated | Fair to Good | Fair to Good | Excellent | Good | Good | Poor | |
Solvent Resistance: | Aliphatic Hydrocarbons | Poor | Poor | Poor | Excellent | Good | Excellent |
Aromatic Hydrocarbons | Poor | Poor | Poor | Good | Fair | Fair to Good | |
Oxygenated (ketones, etc.) | Good | Good | Good | Poor | Poor | Poor | |
Lacquer Solvents | Poor | Poor | Poor | Fair | Poor | Poor | |
Swelling in Lubricating Oil | Poor | Poor | Poor | Very Good | Good | Excellent | |
Oil & Gasoline | Poor | Poor | Poor | Excellent | Good | Excellent | |
Animal & vegetable Oils | Poor to Good | Poor to Good | Excellent | Excellent | Good | ||
Water Absorption | Very Good | Good to Excellent | Very Good | Fair to Good | Good | Good @ room temp., Poor @ 212º F. | |
Resistance to: | Ozone | Fair | Fair | Excellent | Fair | Excellent | Outstanding |
Sunlight Aging | Poor | Poor | Very Good | Poor | Very Good | Good | |
Heat Aging | Good | Very Good | Excellent | Excellent | Excellent | Good | |
Flame | Poor | Poor | Poor | Poor | Good | Fair | |
Heat | Good | Excellent | Excellent | Excellent | Excellent | Good | |
Cold | Excellent | Excellent | Good | Good | Good | Excellent | |
Oxidation | Good | Good | Excellent | Good | Excellent | Excellent |