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Pospisil, Polymer Degrad and Stability, 1993, 40, 217
The 2,6-ditert-butyl-4-hydroxytoluene (BHT,
B121) is the simplest phenolic antioxidant. It
yields a stable phenoxy radical i) by
mesomery, ii) steric effect due to large tert-
butyl, and iii) captodative effect.
WHAT TO REGULATE ?
PRIMARY ANTIOXYDANT:
HINDERED PHENOLS
H
H
H
A
O
A
O
A
H
O
A
O
A
H
O
H
A
O
A
O
H
H
A
O
A
O
A
H
O
Quinomethide
Double bond
polymeric radical
mesomers
Isomerisation
Don H
Dismutation
Dismutation
+