Ethylene propylene rubber is used for many purposes. This is considered to be the most water resistant rubber available. This type of rubber is widely used for manufacturing of the sheeting used at high temperatures. This is one of the most commonly used and fastest growing synthetic rubbers having both general-purpose and specialty applications. As per a report in 2000, sales of this rubber has grown to 870 metric tons or 1.9 billion pounds. Commercial application of this rubber started in 1960.

It is to be noted that the abbreviation of this rubber is EPM or EPDM which means that the rubber consists of ethylene and propylene (EPM), but the letter D tells us that a diene is also present (EPDM). The third monomer, that is, diene makes it possible to cure the rubber with sulfur since it introduces double bonds in the structure which changes the structure to an unsaturated polymer.

Properties of ethylene propylene diene monomer

• This rubber has excellent resistance to atmospheric ageing and oxygen.
• It has good ozone resistance.
• It has good resistance to most water-based chemicals.
• It also has resistance to vegetable-based hydraulic oils.
• It has however very poor resistance to mineral oils and di-ester based lubricants.
• This rubber has stable, saturated polymer backbone structure.
• It has excellent resistance to heat.
• It has good electrical resistivity.
• The EPM or EPDM rubber is also resistant to polar solvents like water, acids, alkalies, phosphate esters and many ketones and alcohols.

Application of Ethylene propylene rubber
Since EPM or EPDM rubber does not crack outdoors, it is widely used for seals in buildings and in the automotive industry. Some other applications are steam hose, high temperature-resistant seals and roll covers. Polymerization and catalyst technologies in use today provide the ability to design EPM to meet specific and demanding application and processing needs. This has resulted in broad usage in following industries:

• Automotive weather-stripping and seals
• Glass-run channel
• Radiator
• Garden and appliance hose
• Tubing
• Belts
• Electrical insulation
• Roofing membrane
• Rubber mechanical goods
• Plastic impact modification
• Thermoplastic vulcanizates
• Motor oil additive applications

Conclusion
Ethylene-propylene rubbers are one of the most versatile, fastest growing synthetic rubber polymers. Excellent resistance to heat, oxidation, ozone and weather aging have led to increased demand for this rubber in automotive, construction, and mechanical goods applications. Current and emerging advanced polymerization and catalyst technologies have also led to design of polymers to meet application and processing needs that are very important to meeting the ever-increasing demands for product quality, uniformity and performance.