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Antioxidant mechanism of a 3‐arylbenzofuranone containing a 2′‐hydroxyl group
Author(s) -
Meng Xin,
Qiu Zhihao,
Xin Zhong
Publication year - 2013
Publication title -
journal of vinyl and additive technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 35
eISSN - 1548-0585
pISSN - 1083-5601
DOI - 10.1002/vnl.21307
Subject(s) - radical , chemistry , intramolecular force , hydrogen bond , substituent , benzofuran , hydroxyl radical , medicinal chemistry , antioxidant , hydrogen , organic chemistry , molecule
5‐Methyl‐7‐ tert ‐butyl‐3‐(2′hydroxyl‐5′‐methylphenyl)3 H ‐benzofuran‐2‐one (PCRBF2), is a better scavenger of 2,2‐diphenyl‐1‐picrylhydrazyl radicals than benzofuranone analogs without the 2′‐substituent, which indicates that PCRBF2 will cause good stabilization in polymers. To prove this further, antioxidation by PCRBF2 and other benzofuranone analogs, namely, 5‐methyl‐7‐ tert ‐butyl‐3‐(3′,4′‐dimethylphenyl)3 H ‐benzofuran‐2‐one (OXBF2) and 5‐methyl‐7‐ tert ‐butyl‐3‐(2′,5′‐dimethylphenyl)3 H ‐benzofuran‐2‐one (PXBF2), was comparatively studied in polypropylene. The resulting antioxidant activity order of these benzofuranones was PCRBF2 > OXBF2 > PXBF2, an observation showing that the hydroxyl group in the 2′‐position does not weaken the antioxidant activity of benzofuranone, but, on the contrary, increases it. Analyses by FTIR revealed intramolecular hydrogen bonding between the 3‐position hydrogen and the oxygen of the 2′‐hydroxyl group, which makes the 2′‐hydroxyl hydrogen of PCRBF2 more reactive than the 3‐position reactive hydrogen. Thus the hydroxyl group reacts with radicals first. J. VINYL ADDIT. TECHNOL., 19:198‐202, 2013. © 2013 Society of Plastics Engineers