Phenolic antioxidants were identified by thin-layer chromatography in 102 samples of medical and pharmaceutical rubber articles. Acetone extracts of rubber were spotted on silica gel plates with a concentrating zone. Benzene, benzene-hexane (75:25) and benzene-ethyl acetate-acetone (100:5:1) were used as developing solvents and N-chloro-2,6-dichloro-p-benzoquinone monoimine as spray reagent. Only 8 sterically hindered phenols among the 57 previously listed were found in current use. Reasons for choosing these compounds and the experimental conditions are discussed.

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http://dx.doi.org/10.1016/s0021-9673(01)94284-0DOI Listing

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