An antioxidant in rubber materials is a chemical additive used to protect rubber from degradation caused by oxidation. Oxygen, heat, and environmental factors can cause rubber to harden, crack, or lose elasticity over time. Antioxidants help slow down this aging process, extending the lifespan and durability of rubber products.

How Oxidation Affects Rubber

Oxidation occurs when oxygen reacts with the polymer chains in rubber, leading to:

• Hardening & Brittleness – Loss of flexibility and elasticity.

• Surface Cracks – Small cracks that grow over time, especially under stress.

• Discoloration & Degradation – Fading and material breakdown.

Types of Antioxidants Used in Rubber

1. Amine-Based Antioxidants

   • Highly effective but can cause discoloration.

   • Example: Phenyl-β-naphthylamine (PBN), used in industrial applications.

2. Phenolic Antioxidants

   • Non-staining, often used in consumer rubber goods.

   • Example: Butylated Hydroxyanisole (BHA).

3. Phosphite & Thioester Antioxidants

   • Provide secondary antioxidant effects, often used with other stabilizers.

   • Example: Dilauryl thiodipropionate (DLTDP).

Applications of Antioxidants in Rubber

• Tires – Prevents cracking and hardening due to ozone and heat.

• Seals & Gaskets – Ensures long-term flexibility in harsh environments.

• Industrial Belts & Hoses – Extends service life under mechanical stress.

• Electrical Insulation – Protects against thermal degradation.

Antioxidants are essential in rubber formulations to ensure durability, especially in high-temperature, outdoor, or high-stress applications.