What are the differences between amine antioxidants and phenolic antioxidants?

Amine antioxidants and phenolic antioxidants mainly have the following differences:

1. Antioxidant mechanisms:

• Amine antioxidants mainly interrupt the oxidation chain reaction by trapping free radicals. They can react with peroxy radicals to form stable nitrogen-oxygen free radicals, thereby inhibiting the oxidation process.

• Phenolic antioxidants prevent the oxidation reaction by providing hydrogen atoms to free radicals and forming relatively stable phenoxy radicals themselves.

2. Thermal stability:

• Amine antioxidants usually have good thermal stability and can still exert good antioxidant effects in high-temperature environments.

• The thermal stability of phenolic antioxidants is relatively weak, and their antioxidant effects may decrease at higher temperatures.

3. Discoloration issue:

• Amine antioxidants may cause discoloration of products during use, which is disadvantageous in some applications with high color requirements.

• Phenolic antioxidants generally cause less discoloration problems.

4. Toxicity:

• Some amine antioxidants may have certain toxicity.

• The toxicity of phenolic antioxidants is usually relatively low.

5. Synergistic effect:

• The synergistic effect of amine antioxidants with certain other types of antioxidants is relatively weak.

• Phenolic antioxidants often have a strong synergistic effect with other antioxidants such as thioesters.

6. Scope of application:

• Amine antioxidants are widely used in fields such as rubber and lubricating oil.

• Phenolic antioxidants are more commonly used in products such as plastics, oils, and coatings.

In conclusion, there are certain differences in performance characteristics and application fields between amine and phenolic antioxidants. The appropriate antioxidant should be selected according to specific application requirements.