Thermooxidative stability of polypropylene with regard to the concentration of hydroperoxides in the presence of phenolic stabilizer

Ryšavy̌, D.

doi:10.1016/0032-3861(67)90047-x

Cited by 13 publications

(1 citation statement)

References 2 publications

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“…More importantly, all the phenolic compounds have demonstrated antioxidation abilities. For example, 2,2′-methylenebis(6-tert-butyl-4-methylphenol), also known as antioxidant 2246, engages in direct oxidation 49 and has been used as an antioxidant in the market. Therefore, the results of TLC, HPLC and GC/MS analysis further verified the production of phenolics, flavonoids and saponins with antioxidant behaviour derived from fungal endophytes.…”

Section: Discussionmentioning

confidence: 99%

Fungal endophyte-derived Fritillaria unibracteata var. wabuensis: diversity, antioxidant capacities in vitro and relations to phenolic, flavonoid or saponin compounds

Pan

Cai

et al. 2017

Sci Rep

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Diverse fungal endophytes are rich fungal resources for the production of an enormous quantity of natural products. In the present study, 53 fungal endophytes were isolated from the bulbs of Fritillaria unibracteata var. wabuensis (FUW). Of these, 49 strains were identified and grouped into 17 different taxa, and priority was conferred to the Fusarium genus. All fungal fermented filtrates displayed antioxidant activities. The DPPH activity, total antioxidant capacities (ABTS), reduction power (FRAP), total phenolic content (TPC), total flavonoid content (TFC) and total saponin content (TSC) were evaluated using petroleum ether, ethyl acetate, n-butyl alcohol and ethanol fractions extracted from five representative fungal cultures. The last three fractions showed more potent antioxidant activity than the first fraction. Significant positive correlations were found between the compositions (TPC, TFC and TSC) and antioxidant capacities (DPPH, ABTS and FRAP). In addition, multifarious natural antioxidant components were identified from the fungal extracts, including gallic acid, rutin, phlorizin, 2,4-di-tert-butylphenol and 2,6-di-tert-butyl hydroquinone; these were determined preliminarily by TLC-bioautography, HPLC and GC-MS analysis. This study showed abundant fungal resources in FUW. Phenolics, flavonoids and saponins are crucial bioactive constituents in these abundant fungal endophytes and can be viewed as new potential antioxidant resources.

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Section: Discussionmentioning

confidence: 99%

Fungal endophyte-derived Fritillaria unibracteata var. wabuensis: diversity, antioxidant capacities in vitro and relations to phenolic, flavonoid or saponin compounds

Pan

Cai

et al. 2017

Sci Rep

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Contribution to the study of mechanism of stabilizing action of esters of phosphorous acid

Ryšavy̌

Sláma

1969

Angew. Makromol. Chem.

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The rate of the reaction of a series of phosphites with cyclohexene hydroperoxide and cyclohexene peroxy radicals was studied. The results of the measurements were compared with the stabilization efficiency of the same compounds in isotactic and in atactic polypropylene at 160°C and 120°C respectively and during the course of atmospheric ageing. It was found the reverse relation between the stabilization efficiency and the reaction constants of the reaction of phosphites with hydroperoxides. The main stabilization reaction of the phosphorous stabilizers seems to be the reaction of phosphites or of their decomposition products with radicals. The possibility of splitting off of free phenol from phosphites as a result of the reaction of the esters with hydroperoxide groups was checked. ZUSAMMENFASSUNG :Die Reaktionsgeschwindigkeit einer Reihe von Phosphiten rnit Cyclohexenylhydroperoxid und mit Peroxy-Radikalen des Cyclohexens wurde untersucht. Die Ergebnisse wurden mit der Stabilisierungswirksamkeit derselben Verbindungen an isotaktischem Polypropylen bei 120°C und 160°C und wiihrend der atmospharischen Alterung verglichen. Es wurde festgestellt, daD die Stabilisierungswirksamkeit den Reaktionskonstanten der Phosphite mit den Hydroperoxiden umgekehrt proportional ist. Die wichtigste Stabilisationsreaktion der Phosphitstabilisatoren ist die Reaktion der Phosphite bzw. der aus ihnen entstehenden Stoffe rnit den Radikalen. Die Moglichkeit der Bildung von freien Phenolen als Folge der Reaktion der Phosphite mit Hydroperoxidgruppen wurde uberpriift.

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Oxygen uptake: A procedure for evaluating oxidative stability and performances of polymers

Zaharescu¹

2001

Materials Research Innovations

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Thermooxidative stability of polypropylene with regard to the concentration of hydroperoxides in the presence of phenolic stabilizer

Cited by 13 publications

References 2 publications

Fungal endophyte-derived Fritillaria unibracteata var. wabuensis: diversity, antioxidant capacities in vitro and relations to phenolic, flavonoid or saponin compounds

Fungal endophyte-derived Fritillaria unibracteata var. wabuensis: diversity, antioxidant capacities in vitro and relations to phenolic, flavonoid or saponin compounds

Contribution to the study of mechanism of stabilizing action of esters of phosphorous acid

Oxygen uptake: A procedure for evaluating oxidative stability and performances of polymers

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