Thermoset rubber refers to a type of rubber that undergoes an irreversible chemical curing process, known as vulcanization, to form a durable and heat-resistant material. Once cured, thermoset rubbers cannot be melted or reshaped, distinguishing them from thermoplastic elastomers (TPEs).

Key Characteristics of Thermoset Rubber

1. Permanent Crosslinking

   • During vulcanization, sulfur, peroxides, or other agents create strong crosslinks between polymer chains, giving the rubber its elasticity and durability.

   • This structure makes thermoset rubbers highly resistant to deformation and melting.

2. Heat & Chemical Resistance

   • Thermoset rubbers withstand high temperatures without softening or breaking down.

   • They also resist oils, chemicals, and weathering, making them ideal for demanding applications.

3. High Strength & Stability

   • Once cured, thermoset rubber maintains its shape and properties, even under mechanical stress.

   • It has superior compression set resistance, meaning it retains its elasticity over time.

4. Non-Recyclable & Non-Remoldable

   • Unlike thermoplastics, thermoset rubbers cannot be melted and reshaped after curing.

   • This makes processing waste harder to recycle but enhances performance for long-term applications.

Common Types of Thermoset Rubber

1. Natural Rubber (NR) – High elasticity and strength, used in tires and industrial belts.

2. Styrene-Butadiene Rubber (SBR) – Good abrasion resistance, commonly found in tires and seals.

3. Nitrile Rubber (NBR) – Excellent oil and fuel resistance, used in hoses and gaskets.

4. Ethylene Propylene Diene Monomer (EPDM) – Weather-resistant, used in roofing, seals, and outdoor applications.

5. Silicone Rubber (SI) – High-temperature resistance, used in medical, automotive, and aerospace applications.

6. Fluoroelastomers (FKM, e.g., Viton®) – Excellent chemical and heat resistance, used in automotive and industrial seals.

Advantages of Thermoset Rubber

• Excellent Heat Resistance – Does not melt or soften under high temperatures.

• Superior Chemical Resistance – Withstands oils, solvents, and harsh chemicals.

• Long-Term Elasticity – Maintains flexibility and shape over time.

• Strong Mechanical Properties – High tear, abrasion, and compression resistance.

Applications of Thermoset Rubber

• Automotive: Tires, engine seals, hoses, and vibration dampeners.

• Aerospace: High-temperature seals and insulation.

• Industrial: Conveyor belts, gaskets, and anti-vibration mounts.

• Medical & Food Industry: Silicone-based seals and tubing.

• Electrical Insulation: EPDM and silicone rubber used in cables and connectors.

Conclusion

Thermoset rubbers are essential for high-performance applications where heat resistance, durability, and chemical stability are required. While they cannot be remelted or reshaped, their superior properties make them the preferred choice for tires, seals, hoses, and industrial components.