butyl rubber

Butyl Rubber Products

Physical & Mechanical Properties / Chemical Resistance / Thermal Properties / <Environmental Performance / Butyl Applications

What is Butyl Rubber?

Butyl rubber, also known as isobutylene-isoprene rubber (IIR), is a versatile, general purpose, synthetic rubber and a copolymer of isobutylene with isoprene. Butyl rubber is produced by polymerization of about 98% of isobutylene with about 2% of isoprene. It is ideal for shock absorption, offers particularly low gas and moisture permeability, exceptional resistance to heat, weather, ozone, abrasion, tearing, chemical corrosion and much more.

Butyl rubber is impermeable to air, so it is useful in many applications requiring an airtight rubber. Butyl’s strength, flexibility, low gas permeability and airtight characteristics mean it is also ideal for high pressure or vacuum sealed applications. The first widespread application of butyl rubber, however, was tire inner tubes. This application is still central for butyl rubber to this day.

Butyl is an incredibly versatile synthetic rubber. However, it is not recommended for use in applications involving contact with petroleum oils. Continue below for more properties and advantages of Butyl:

Properties of Butyl Rubber

  • Isobutylene-isoprene rubber (IIR)
  • ASTM D-2000 Classification AA, BA, CA (Standard Classification System for Rubber Products in Automotive Applications)
  • Chemical Definition Isobutylene Isoprene Rubber

Butyl Rubber Processing

  • Transfer Molding
  • Injection Molding
  • Compression Molding

Physical & Mechanical Properties

  • Durometer or Hardness Range: 40 – 90 Shore A
  • Tensile Strength Range: 500 – 3,000 PSI
  • Elongation (Range %): 300% – 850%
  • Abrasion Resistance: Fair to Good
  • Adhesion to Metal: Good
  • Adhesion to Rigid Materials: Fair – Good
  • Compression Set: Fair – Good
  • Flex Cracking Resistance: Good – Excellent
  • Impact Resistance: Good
  • Resilience & Rebound: Fair – Good
  • Tear Resistance: Good
  • Vibration Dampening: Excellent

Chemical Resistance

  • Dilute Acids: Good – Excellent
  • Concentrated Fair: – Excellent
  • Organic Acids (Dilute): Good
  • Organic Acids (Concentrated): Fair to Good
  • Inorganic Acids: Good
  • Alcohols: Good – Excellent
  • Aldehydes: Good
  • Dilute Alkalies: Good – Excellent
  • Concentrated Alkalies: Good – Excellent
  • Amines: Good
  • Animal & Vegetable Oils: Good – Excellent
  • Brake Fluids, Non-Petroleum Based: Good
  • Diester Oils: Poor – Good
  • Alkyl Phosphate Esters: Good – Excellent
  • Aryl Phosphate Esters: Excellent
  • Ethers: Poor – Fair
  • Aliphatic Hydrocarbon Fuel: Poor
  • Aromatic Hydrocarbon Fuel: Poor
  • Extended Fuel (Oxygenated): Poor
  • Halogenated Solvents: Poor
  • Hydrocarbon, Halogenated: Poor
  • Ketones: Poor – Excellent
  • Lacquer Solvents: Fair – Good
  • 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: Poor
  • Solvent Resistance: Poor

Thermal Properties

  • Low Temperature Range: 70ºF to – 40ºF
  • Minimum for Continuous Use (Static): 60ºF
  • Brittle Point: 90º F to – 50° F
  • High Temperature Range: +250º F to +300ºF
  • Maximum for Continuous Use (Static): +300ºF

Environmental Performance

  • Colorability: Good
  • Flame Resistance: Poor
  • Gas Permeability: Good
  • Odor: Good
  • Ozone Resistance: Excellent
  • Oxidation Resistance: Excellent
  • Radiation Resistance: Poor – Good
  • Steam Resistance: Good – Excellent
  • Sunlight Resistance: Excellent
  • Taste Retention: Fair – Good
  • Weather Resistance: Excellent
  • Water Resistance: Good – Excellent

Applications of Butyl Rubber

  • Shock mounts
  • Sealant for rubber roof repair
  • Tubeless tire liners
  • Inner tubes
  • Stoppers for glass bottles, medicine bottles, and pharmaceuticals
  • Used in sealants and adhesives
  • Tank Liners
  • Sealants, hoses, and mechanical goods
  • Adhesives
  • Agricultural chemicals
  • O-rings
  • Electrical fluids
  • Personal care products
  • Pigment concentrates
  • Rubber & Polymer modification

*The usual working temperature range of butyl products is -50°C (-25°C) to +120°C.

butyl rubber molding

Qualiform ISO Certified Butyl Manufacturer

Qualiform Rubber Molding is a full-service custom rubber molding company. We can mold standard OEM replacement stars, custom finger lengths and configurations. If you would like to develop a recycling star for an application or media processing, our expert technical staff is available to consult on design and property requirements.

As a leading butyl rubber products manufacturer, Qualiform offers a full-range processing, development and testing capabilities.  We offer custom rubber molding services, rubber compression moldingrubber injection moldingrubber transfer molding, and rubber to metal bonding. Furthermore, we are experts in problem-solving in all aspects of rubber molding and rubber to metal bonding. Qualiform can offer effective, custom solutions for virtually any project.

With more than 40 years experience, customers rely on Qualiform for precision rubber parts manufacturing to get the parts they need.  Contact our technical staff at (330) 336-6777 to learn more about Qualiform can help you.

Qualiform Proprietary Blend

Qualiform also offers a proprietary butyl blend with reinforcing fibers. This blend increases wear resistance, durometer, abrasion resistance, toughness and performance properties by implementing reinforcing fibers into the materials. We offer our proprietary blend for all our available rubber materials:

  • EPDM Rubber
  • Natural Rubber
  • Neoprene Rubber
  • Nitrile Rubber
  • Rigid & Flexible Rubber
  • Synthetic Rubber
  • Thermoplastic Elastomers (TPE)
  • Viton Rubber
Factors Affecting Rubber Tolerances
Interested in Butyl or Qualiform’s other offered rubber materials? Contact Qualiform today to receive expert material recommendations.
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