Radical Scavengers

1. Mechanism
2. Lactones
3. Acrylated Bis-Phenols

Mechanism

Radical scavengers are antioxidants capable of trapping radicals. Scavenging of alkyl radicals would immediately inhibit the autoxidation cycle. Under oxygen deficient conditions alkyl radical scavengers contribute significantly to the stabilization of the polymer. Scavenging the extremely reactive alkoxy and hydroxy radicals is practically not possible.

Carbon centered radical scavengers, such as lactones and acrylated bis-phenols, are extremely effective in oxygen deficient environments.

Lactones

Lactones (Benzofuranone derivatives) are powerful radical scavengers. Even when added in small amounts, they help control melt stability during polymer processing.

Substituted Benzofuranone are excellent radical scavengers. They are mainly used in combination with phenolic compounds and phosphite to provide materials excellent performance even at low concentrations.

Acrylated Bis-Phenols

Acting as traditional hindered phenols, acrylate functionalized hindered phenols are efficient C-radical scavengers.

Acrylated Bis-Phenols - Mechanism

They are very effective in preventing styrene copolymers from crosslinking or degrading during processing, particularly under oxygen deficient conditions. They are usually used in conjunction with other stabilization chemistries.