Isoprene Rubber (IR)

The isoprene rubber (or IR rubber) is very much like natural rubber but made artificially or synthetically. The chemical name of isoprene rubber is synthetic cis-polyisoprene. Essentially similar to natural rubber in properties, this rubber may be somewhat weaker because it is not 100% the cis-isomer. This rubber is used in the same type of products as natural rubber.

Properties of Isoprene Rubber

• The physical properties of IR rubber are in general somewhat inferior to those of natural rubber but, in principle, the two types of rubber are quite similar.
• This rubber has almost the same chemical structure as natural rubber (polyisoprene).
• It does not contain proteins, fatty acids and the other substances that are present in natural rubber.
• IR rubber demonstrates lower green strength, slower cure rates, lower hot tear, and lower aged properties than natural rubber.
• PR exceeds the natural types in consistency of product, cure rate, purity and processing.
• In addition, isoprene rubber has the unique property in mixing, extrusion, molding, and calendering processes.

Applications of Isoprene Rubber

• Isoprene Rubber or synthetic polyisoprene is used in a wide variety of industries and applications requiring low water swell, high gum tensile strength, good resilience, good tack and high hot tensile.
• Gum compounds based on IR are used in rubber bands, cut thread, baby bottle nipples, and extruded hose.
• Black loaded compounds of this rubber find use in tires, motor mounts, shock absorber bushings, pipe gaskets, and many other molded and mechanical goods.
• Mineral filled systems find applications in footwear, sponge, and sporting goods.
• Recent reports about allergic reactions to proteins present in natural rubber have prompted increased usage of the more pure IR in various applications.

Liquid Isoprene Rubber (LIR)

Liquid Isoprene Rubber (LIR) is a colorless, transparent and almost odorless viscous liquid rubber. It acts as a reactive plasticizer. It is, in fact, the rubber having highest molecular weight among those materials that can perform plasticizing functions. Liquid isoprene rubber can be vulcanized, co vulcanized and co cross linked with solid rubbers such as NR, SBR, BR and EPDM using sulfur or peroxide.

Applications of Liquid Isoprene Rubber

As mentioned above, liquid isoprene rubber can act as a reactive plasticizer, it is used in the following applications.

• Rubber goods like tires, belts, hose, footwear etc.
• Adhesives including solution, hot melt, crosslink and latex.
• Sealants in automobile industry.
• Liquid isoprene rubber is also used in some other applications like in printing plates, coating, lubricants and binders.

Conclusion About Isoprene Rubber

Synthetic polyisoprene or IR represents one of the important classes of polymers produced in a solution medium. Modern techniques have permitted the production of a synthetic analog of natural rubber with improved uniformity and processing.

Other Types of Synthetic Rubber