Antioxidants and Costabilizers are chemical additives used to protect polymers, plastics, and other materials from oxidative degradation during processing and throughout their service life. Thermal processing exposes polymers to high temperatures and mechanical shear, generating free radicals and peroxides that cause chain scission, discoloration, and loss of physical properties. Antioxidants and costabilizers work by interrupting these degradation pathways, either by scavenging free radicals, decomposing peroxides, or neutralizing acidic byproducts. Available in several chemical types including phosphites, hindered phenols, bisphenols, ESBO, and BHT, each offers distinct stabilization mechanisms suited to specific polymer systems and processing conditions.

Phosphite antioxidants function as secondary antioxidants and processing stabilizers by decomposing hydroperoxides formed during thermal processing before they can generate harmful free radicals. They are widely used in combination with primary antioxidants to provide synergistic stabilization in polyolefins, PVC, engineering plastics, and coatings, particularly during high-temperature extrusion and molding operations.

Hindered Phenol antioxidants are primary antioxidants that scavenge free radicals generated during oxidative degradation, effectively interrupting the chain reaction that leads to polymer breakdown. They provide long-term thermal and oxidative stability and are extensively used in polyolefins, styrenics, elastomers, and adhesives where sustained performance over the product's service life is required.

Bisphenol antioxidants are high-performance primary antioxidants offering excellent thermal stability and low volatility. They are particularly effective in rubber and elastomer applications, providing outstanding protection against heat aging and oxidative degradation in tires, belts, hoses, and other rubber products.

ESBO (Epoxidized Soybean Oil) is a bio-based costabilizer and plasticizer widely used in PVC formulations. It acts as a secondary stabilizer by scavenging hydrochloric acid released during PVC thermal degradation, thereby extending the effectiveness of primary stabilizers. It also functions as a secondary plasticizer, improving flexibility and compatibility in flexible PVC applications such as films, cables, and flooring.

BHT (Butylated Hydroxy Toluene) is a widely used primary antioxidant and free radical scavenger that provides effective short-term protection during processing and storage. It is commonly used in polyolefins, rubber, adhesives, and petroleum products to prevent oxidative rancidity and discoloration during manufacturing and shelf storage.

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