Natural Rubber
What is Natural Rubber?
Natural rubber, also known as polyisoprene rubber, consists of polymers of the compound isoprene as well as impurities from other organic compounds and some water. It is harvested in the form of latex from the sap of rubber trees. This latex is then refined into natural rubber for processing. Natural rubber is both an elastomer and a thermoplastic. Vulcanizing natural rubber creates a thermoset material.
Natural rubber is used widely in various applications and industries whether alone or as a compound with other materials. Some of its advantages include high durability, stretch ratio and water impermeability.
Read more below for advantages and properties of Natural rubber:
Advantages of Natural Rubber
- Extensive Hardness Range
- Color ranges from translucent (soft rubber) to black (hard rubber)
- Natural rubber can be compounded to meet specific application requirements
- Outstanding vibration dampening and noise silencing properties
- Can be manufactured for both electrical insulating or full conductivity
- Protection and sealing properties
Properties of Natural Rubber
- ASTM D-2000 Classification AA (Standard Classification System for Rubber Products in Automotive Applications)
- Chemical Definition: Polyisoprene
- Abbreviations: NR
Processing
- Transfer Molding
- Injection Molding
- Compression Molding
Physical & Mechanical Properties
- Durometer: 30 – 95 Shore A
- Tensile Strength: 500 – 3,500 PSI
- Elongation (Range %): 300% – 900%
- Abrasion Resistance: Good – Excellent
- Adhesion to Metal: Excellent
- Adhesion to Rigid Materials: Excellent
- Compression Set: Excellent
- Flex Cracking Resistance: Excellent
- Impact Resistance: Good – Excellent
- Resilience & Rebound: Excellent
- Tear Resistance: Good – Excellent
- Vibration Dampening: Good – Excellent
Chemical Resistance
- Dilute Acids: Fair – Excellent
- Concentrated Acids: Poor – Good
- Organic Acids (Dilute): Fair – Good
- Organic Acids (Concentrated): Good
- Inorganic Acids: Good
- Alcohols: Good – Excellent
- Aldehydes: Good
- Dilute Alkalies: Fair – Excellent
- Concentrated Alkalies: Fair – Good
- Amines: Poor – Fair
- Animal & Vegetable Oils: Poor – Good
- Non-Petroleum Brake Fluieds: Good
- Diester Oils: Poor
- Alkyl Phosphate Esters: Poor
- Aryl Phosphate Esters: Poor
- Ethers: Poor
- Aliphatic Hydrocarbon Fuel: Poor
- Aromatic Hydrocarbon Fuel: Poor
- Extended Fuel (Oxygenated): Poor
- Halogenated Solvents: Poor
- Halogenated Hydrocarbon: Poor
- Ketones: Fair – Good
- Lacquer Solvents: Poor
- LP Gases & Fuel Oils: Poor
- Mineral Oils: Poor
- Oil Resistance: Poor
- Aromatic Petroleum: Poor
- Non-Aromatic Petroleum: Poor
- Ammonia Refrigerant: Good
- Refrigerant Halofluorocarbons: R-12, R-13
- Refrigerant Halofluorocarbons with Oil: Poor
- Silicone Oil: Good
- Solvent Resistance: Poor
Thermal Properties
- Low Temperature Range: -20ºF – -70ºF
- Minimum for Continuous Use (Static): -60ºF
- Brittle Point: -80ºF
- High Temperature Range: +180ºF – +220ºF
- Maximum for Continuous Use (Static): +180ºF
Environmental Performance
- Colorability: Poor
- Flame Resistance: Fair – Good
- Gas Permeability: Fair – Good
- Odor: Good – Excellent
- Ozone Resistance: Poor
- Oxidation Resistance: Good
- Radiation Resistance: Fair – Good
- Steam Resistance: Good
- Sunlight Resistance: Poor – Fair
- Taste Retention: Fair – Good
- Weather Resistance: Poor – Fair
- Water Resistance: Excellent
Applications of Natural Rubber
Natural Rubber’s exceptional strength and compression set make it an ideal material for various engineering applications and many other industries:
- Anti-Vibration Mounts
- Tires
- Springs
- Bearings
- Adhesives
- Rubber Bands
- Shock Mounts
- Gaskets
- Seals
- Rolls
- Hoses and Tubing
*Natural rubber is NOT RECOMMENDED for applications in which components are exposed to ozone, oils, or solvents.