Easy understanding of phenolic antioxidants for polymers principle

Phenolic antioxidants for polymers are mainly used to delay the oxidative degradation of polymers and extend their service life.

How it Works ?
Phenolic antioxidants donate hydrogen atoms (-H) to peroxyl radicals (ROO·), generating stable phenolic radicals and peroxides (ROOH), thereby interrupting the free radical chain reaction and preventing polymer chain breakage and crosslinking. Common hindered phenolic antioxidants, such as BASF Irganox 1425 and BASF Irgafos 168, exhibit steric hindrance, effectively stabilizing phenolic radicals and reducing further oxidation.

Applications of phenol antioxidants:
Plastics and rubbers: Improve heat resistance, weatherability, and mechanical properties of materials such as polyethylene (PE), polypropylene (PP), and polyamide (PA).
Coatings and adhesives: Enhance weatherability and adhesion of coatings, reducing yellowing and chalking.
Electronic and electrical appliances: Protect insulation materials and plastic components from high temperature and high humidity environments.

Advantages and Limitations:
Advantages: Excellent antioxidant properties, good thermal stability, and good compatibility with polymers. Limitations: Some phenolic antioxidants may migrate or precipitate at high temperatures or during long-term use, affecting material properties. They may also present compatibility issues with certain polar polymers.

Development Trends in Phenolic Antioxidants:
Higher Molecular Weight: Increasing the molecular weight of antioxidants through polymerization or grafting techniques reduces migration and volatilization, enhancing durability.
Multifunctionalization: Combining with other additives (such as light stabilizers and antistatic agents) creates synergistic effects and meets complex operating requirements.
Greening: Developing bio-based or biodegradable phenolic antioxidants reduces environmental impact.