Mechanism of action of phosphites in polyolefin stabilisation

Neri, C.; Costanzi, S.; Riva, Rosa Maria; Farris, RJ; Colombo, Roberto

doi:10.1016/0141-3910(95)00057-s

Cited by 35 publications

(11 citation statements)

References 7 publications

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“…It is interesting to note that in a previous study of multiextruded PP Scheirs et al23 found that after one extrusion less color is produced in PP stabilized with Ultranox 626 ™ [bis(2,4‐di‐ tert‐ butylphenyl)pentaerythrityl diphosphate] than is produced in the same polymer stabilized with Irgafos 168. Neri et al28 found a similar trend to Scheirs et al23 after 10 extrusion passes in a study using the same phosphites in PP. Both Scheirs et al23 and Neri et al28 compared the phosphites at equal phosphorus loadings; hence, Irgafos 168 was used at twice the concentration of Ultranox 626, thereby invoking a threefold higher propensity of the formulation to form chromophoric compounds.…”

Section: Resultssupporting

confidence: 63%

“…Neri et al28 found a similar trend to Scheirs et al23 after 10 extrusion passes in a study using the same phosphites in PP. Both Scheirs et al23 and Neri et al28 compared the phosphites at equal phosphorus loadings; hence, Irgafos 168 was used at twice the concentration of Ultranox 626, thereby invoking a threefold higher propensity of the formulation to form chromophoric compounds.…”

Section: Resultssupporting

confidence: 63%

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Evaluation of the oxidative stability of multiextruded polypropylene as assessed by physicomechanical testing and simultaneous differential scanning calorimetry-chemiluminescence

Fearon

Marshall

Billingham

et al. 2000

J. Appl. Polym. Sci.

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Common physicomechanical tests comprising impact strength, the melt flow index (MFI), and the yellowness index (YI) were used to study the thermooxidative stability of polypropylene (PP) following multipass extrusion. Differential scanning calorimetry (DSC) coupled with chemiluminescence (CL) monitoring was also used to assess the stability. Three PP formulations were studied: (i) PP‐1 containing 0.050% w/w of the phenolic antioxidant Irganox 1010™, (ii) PP‐2 containing 0.028% w/w Irganox 1010, 0.056% w/w of the phosphite costabilizer Irgafos 168™ and 0.014% w/w of the lactone processing stabilizer HP 136™, and (iii) PP‐3 containing 0.050% w/w Irganox 1010 and 0.100% w/w of the phosphite Ultranox 641™. All formulations contained 0.045% w/w of the hydrotalcite acid scavenger DHT‐4A™. The results suggest that physicomechanical tests cannot reliably detect the small difference in the stability between PP‐2 and PP‐3 but can detect the larger difference between these and the less stable PP‐1. The oxidative induction time (OIT) determined by CL monitoring (i.e., CL– OIT) is consistent with the OIT determined by DSC but has better reliability. The CL–OIT data suggest that PP‐3 has superior oxidative stability to PP‐2 in the early stages of multipass extrusion. However, PP‐2 exhibits a better resistance to yellowing. A correlation between the CL–OIT data and each of the MFI and YI data was found. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 733–741, 2001

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Section: Resultssupporting

confidence: 63%

Section: Resultssupporting

confidence: 63%

Evaluation of the oxidative stability of multiextruded polypropylene as assessed by physicomechanical testing and simultaneous differential scanning calorimetry-chemiluminescence

Fearon

Marshall

Billingham

et al. 2000

J. Appl. Polym. Sci.

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“…Direct reaction with molecular oxygen can have a stabilizing effect if it is competitive with the P þ O 2 reaction. According to Neri et al [35], this should occur only at temperatures higher than 200 C which lie outside the temperature range under investigation here. The absence of phosphiteeoxygen reactions was confirmed in a control reaction where the pure stabilizer was exposed to high oxygen pressure at 80 C [36].…”

Section: Discussionmentioning

confidence: 59%

Modelling of thermal oxidation of phosphite stabilized polyethylene

Djouani

Richaud

Fayolle

et al. 2011

Polymer Degradation and Stability

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Modelling of thermal oxidation of phosphite stabilized polyethylene. Polymer Degradation and Stability, Elsevier, 2011, 96 (7), pp. a b s t r a c tThe thermal oxidation behaviour of polyethylene films stabilized by various weight ratios of organophosphites (Irgafos 168) has been studied at selected temperatures. The duration of the induction period was found to increase proportionally with the stabilizer concentration, even at temperatures as low as 80 C. Particular attention was paid to the phosphiteephosphate conversion during the induction period. A kinetic model, involving volatile and partially soluble hydroperoxide decomposers, was developed in order to simulate these results. With the use of kinetic parameters that can be at least tentatively justified from theoretical considerations, this model gave simulations in reasonable agreement with the experimental observations for stabilizer depletion and carbonyl formation. Of particular note is the fact that, even for non-trivial results such as the shape of the phosphite versus phosphate concentration plots, or phosphate build-up, there was also a quite good agreement.

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“…The decomposition of the hydroperoxide is assumed to be the main mechanism (Scheme 13) for the reactions of different trivalent phosphites and is accompanied by oxidation to the corresponding pentavalent compound. [70,72,73,[75][76][77][78][79] Scheme 16 is more likely than Scheme 15. The reaction of phosphites with peroxyl radicals formed in the autooxidation of organic compounds results in the formation of phosphates and alkoxyl radicals (Scheme 14), which further react with a second phosphite molecule in a way depending on the structures of the phosphorous compound and the alkoxyl radical.…”

Section: By-products Of 4 (Tris (24-di-tertbutylphenyl) Phosphite)mentioning

confidence: 99%

Identification of chemical species created during γ‐irradiation of antioxidant used in polyethylene and polyethylene‐co‐vinyl acetate multilayer film

Dorey¹,

Gaston²,

Girard‐Perier

et al. 2020

J of Applied Polymer Sci

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With the increasing use of γ-irradiated containers made of multilayer polymeric flexible films for food and biopharmaceutical applications, the possible migration of degradation products of the polymers and their additives is becoming a topic of concern. This article aims at highly reliably identifying the degradation products generated after gamma irradiation and their origin to later on assess their potential harmfulness in single-use containers. In this study, GC-MS is used to identify by-products created by γ-irradiation of primary and secondary antioxidants usually present in polyolefin-based biotechnological single-use materials and to confirm identification relevancy based on the literature survey or standard when available. Degradation pathways are proposed to account for the formation of by-products identified during the study and to list intermediates and other by-products present in too small amounts to be detected and identified accurately in all extractable studies.

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Mechanism of action of phosphites in polyolefin stabilisation

Cited by 35 publications

References 7 publications

Evaluation of the oxidative stability of multiextruded polypropylene as assessed by physicomechanical testing and simultaneous differential scanning calorimetry-chemiluminescence

Evaluation of the oxidative stability of multiextruded polypropylene as assessed by physicomechanical testing and simultaneous differential scanning calorimetry-chemiluminescence

Modelling of thermal oxidation of phosphite stabilized polyethylene

Identification of chemical species created during γ‐irradiation of antioxidant used in polyethylene and polyethylene‐co‐vinyl acetate multilayer film

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