摘要:

AbstractThe effect of halogenated and alkylated dihydric phenols on the autoxidation process of tetralin and cumene initiated at 65°C with AIBN has been investigated. The character of substitution effects the antioxidative activity of the derivatives of the pyrocatechol and hydroquinone series in a different way. All halogenated pyrocatechols were less active than unsubstituted pyrocatechol. Their antioxidative activity increased in both substrates proportionally to the number of the halogen atoms. On the other hand the introduction of chlorine atoms into the hydroquinone ring led to a considerable increase in the antioxidative activity compared to hydroquinone and to its alkyl derivatives. In both substrates isomeric dihydric phenols exhibited different retardation of the oxidation course in the step following the induction period. The reasons for the different behavior are discussed

ISSN:0360-8905    

DOI:10.1002/polc.5070400133

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractSelected alkylated and halogenated derivatives of pyrocatechol and hydroquinone were oxidized with oxygen at 150°C in trichlorobenzene. The results allow an evaluation of participation of the direct oxidation of the antioxidant in the overall mechanism of its deactivation during the stabilization of polyolefins. Further data were obtained by oxidation performed in an alkaline medium. Specific relationships between the direct oxidation of halogenated dihydric phenols and their antioxidative activity in polypropylene and low‐molecular weight hydrocarbons are discuss

ISSN:0360-8905    

DOI:10.1002/polc.5070400134

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

摘要:

AbstractAn investigation was made of reactions of 2‐tert‐butylhydroquinone and 4‐tert‐butyl‐pyrocatechol with tert‐butylhydroperoxide and tetralylhydroperoxide in the presence and absence of a cobalt catalyst, modeling the transformations of these antioxidants during inhibited oxidation. The reaction product was a benzoquinone derivative in the first case and a mixture of benzoquinone and hydroxybenzoquinone, in the second. The formation of products also corresponded to the transformations of both isomeric tert‐butylated benzoquinones caused by tert‐butyl hydroperoxide. In agreement with the investigated model the same products of the oxidative transformation of dihydric phenols during inhibited oxidation of tetralin and atactic polypropylene were detected. Under the conditions for oxidative degradation of polyolefins at temperatures above 150°C, deactivation due to direct oxidation with oxygen must also be taken into account. The extent and rate of the formation of transformational products is one of the reasons for different antioxidative activity of isomeric

ISSN:0360-8905    

DOI:10.1002/polc.5070400135

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY

ISSN:0360-8905    

DOI:10.1002/polc.5070400102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1973

数据来源: WILEY