Pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) is a chemical compound composed of four sterically hindered phenols linked through a pentaerythritol core. It is used as primary antioxidant for stabilizing polymers, particularly polyethylene and polypropylene.
Synthesis Base catalysed Michael addition of methyl acrylate to 2,6-di-tert-butylphenol forms the intermediate dibutyl-phloretic ester. High temperature transesterification of this with pentaerythritol gives the final product. Driving this reaction to completion can be difficult and commercial samples often contain low levels of the tri-ester.
Properties The linking of phenols together with pentaerythritol maintains their activity with greatly reduced volatility. This is important during the processing and molding steps where the plastic is heated to molten, typically several hundred degrees.
See also Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate - an inexpensive and commonly used polymer stabiliser Tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate - a polymer stabiliser commonly used to protect against long term heat aging Irganox 1098 - a polymer stabiliser with metal chelation properties
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