Effect of oxygen pressure on the oxidation kinetics of unstabilised polypropylene

Richaud, Emmanuel; Farcas, Fabienne; Bartoloméo, P.; Fayolle, Bruno; Audouin, L.; Verdú, J.

doi:10.1016/j.polymdegradstab.2005.04.043

Cited by 80 publications

(85 citation statements)

References 9 publications

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“…One can observe M n of all the films exposed to an oxygen partial pressure of 30 bars decreased significantly from the beginning of exposure, the chain scission rate being dependent on the oxygen concentration into the polymer. By assuming, as a first approach, that the oxidation rate is proportional to the chain scission rate, this result suggests that oxidation occurs in air and that the oxidation rate depends on oxygen pressure as in many polymers such as polypropylene [28].…”

Section: ) Ageing Conditionsmentioning

confidence: 99%

Oxidative degradation of polylactide (PLA) and its effects on physical and mechanical properties

Rasselet¹,

Ruellan²,

Guinault³

et al. 2014

European Polymer Journal

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142

102

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. AbstractThe thermo-oxidative degradation of polylactide (PLA) films was studied between 70 and 150°C. It was shown that the oxidative degradation of PLA leads to a random chain scission responsible for a reduction of the molar mass. These molar mass changes affect Tg and the degree of crystalllinity, and it was found that Tg decreases according to the Fox-Flory theory whereas the degree of crystalllinity increases due to a chemicrystallization process. A correlation between molar mass and strain at break during oxidation has been established:PLA displays a brittle behaviour when M n falls below 40 kg.mol -1 in agreement with relationships linking the critical value for embrittlement with the molar mass between entanglements.

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Section: ) Ageing Conditionsmentioning

confidence: 99%

Oxidative degradation of polylactide (PLA) and its effects on physical and mechanical properties

Rasselet¹,

Ruellan²,

Guinault³

et al. 2014

European Polymer Journal

Self Cite

142

102

View full text Add to dashboard Cite

show abstract

“…"In fact, under oxygen excess P° mainly reacts with oxygen to form POO° radicals. Termination reactions between P° and P° and between P° and POO° are negligible while termination reactions between POO° + POO° are predominant [7]. As a result, even if the occurrence of some crosslinking event would thus be linked to P° + POO° or to POO°+POO°, crosslink event from P° + P° is removed by increasing oxygen pressure".…”

Section: Sec Measurementsmentioning

confidence: 99%

“…One can define a "critical oxygen concentration" corresponding to the transition between both regimes [7].…”

Section: Assessment Of Kinetic Parametersmentioning

confidence: 99%

“…-Ageing experiments under several oxygen pressures are performed in order to get accurate values for termination rate constants [7], -A special attention is paid to molar mass distribution changes determined by size exclusion chromatography (SEC). The latter technique [9,10] appears to be relevant in comparison with rheometry measurements [4] where part of the oxidized polymer may undergo thermolysis as the measurements are performed in molten state.…”

Section: Introductionmentioning

confidence: 99%

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Molecular and macromolecular structure changes in polyamide 11 during thermal oxidation

Okamba-Diogo

Richaud

Verdú

et al. 2014

Polymer Degradation and Stability

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“…Arrhenius graphs for the thermal initiation rate constant for: This work., Richaud et al [57], Achimsky [58], Achimsky et al [56]. The value of pseudounimolecular kinetic rate constants are determined from the induction times using t ind ¼ 3/k 1u .…”

Section: Resultsmentioning

confidence: 99%

Influence of temperature, UV-light wavelength and intensity on polypropylene photothermal oxidation

François-Heude¹,

Richaud²,

Desnoux³

et al. 2014

Polymer Degradation and Stability

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. a b s t r a c tA criterion based on the energy absorbed by photosensitive species was proposed to describe the contribution of UV-light to the initiation of the polypropylene photothermal oxidation whatever the light source. The calculation of this energy was performed using the widely accepted quantum theory. The criterion was then introduced in two different types of analytical models commonly used to describe the combined effects of UV light and temperature on induction time, namely: the reciprocity law and kinetic model. The limitations of both types of analytical models were then investigated: the latter, derived from a realistic mechanistic scheme, was found to be much more relevant than the former, which is presumably valid in a restricted range of light intensities, essentially due to its empirical origin. Ó

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Effect of oxygen pressure on the oxidation kinetics of unstabilised polypropylene

Cited by 80 publications

References 9 publications

Oxidative degradation of polylactide (PLA) and its effects on physical and mechanical properties

Oxidative degradation of polylactide (PLA) and its effects on physical and mechanical properties

Molecular and macromolecular structure changes in polyamide 11 during thermal oxidation

Influence of temperature, UV-light wavelength and intensity on polypropylene photothermal oxidation

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