Trade names: Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is a hindered phenolic antioxidant commonly used as a polymer stabiliser.

Base catalysed Michael addition of methyl acrylate to 2,6-di-tert-butylphenol forms the intermediate butyl-phloretic ester.

Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is significantly less volatile than simpler phenolic antioxidants such as butylhydroxytoluene (BHT).

It is one of the most common polymer antioxidants, in part because of its comparatively low price.

The stearyl tail reduces volatility and gives good chemical compatibility with plastics but contributes nothing to antioxidant performance.