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dc.contributor.authorEL MAZRY, Chaker
dc.contributor.authorBEN HASSINE, Mouna
dc.contributor.authorCORREC, Olivier
dc.contributor.author
 hal.structure.identifier
COLIN, Xavier
86289 Laboratoire Procédés et Ingénierie en Mécanique et Matériaux [PIMM]
dc.date.accessioned2014
dc.date.available2014
dc.date.issued2013
dc.date.submitted2014
dc.identifier.issn0141-3910
dc.identifier.urihttp://hdl.handle.net/10985/8056
dc.description.abstractThermal aging of an additive free PA 6-6 has been elucidated at 90, 100, 120, 140, 150 and 160 C in airventiled ovens by Fourier transform infrared spectrophotometry, viscosimetry in molten state and uniaxial tensile testing. Oxidation of methylene groups starts after a considerably shorter induction period but reaches a lower maximal rate than in additive free PE. Cleavage of CeN bonds constitutes the main source of chain scissions. It leads to the formation of aldehyde chain-ends and a catastrophic decrease in molar mass. Embrittlement occurs at a very low conversion ratio of the oxidation process, in particular when the concentration of aldehyde chain-ends reaches a critical value of [PH¼O]F z 5.6 10 3 mol l 1, corresponding to a critical value of the number average molar mass ofMnFz17 kg mol 1. At this stage, the entanglement network in the amorphous phase is deeply damaged. A non-empirical kinetic model has been derived from the oxidation mechanistic scheme previously established for PE, but improved by adding elementary reactions specific to polyamides such as the rapid decomposition of unstable hydroxylated amide groups. This model describes satisfyingly the main features of the thermal oxidation kinetics of PA 6-6, but also of other types of aliphatic polyamides studied previously in the literature such as: PA 6, PA 12 and PA 4-6, as long as it is not controlled by oxygen diffusion. At the same time, it confirms the existence of an universal character for the thermal oxidation kinetics of aliphatic polyamides whatever their origin, i.e. their initial molar mass, crystallinity ratio, concentration of impurities, structural irregularities, etc.
dc.language.isoen
dc.publisherElsevier
dc.rightsPost-print
dc.subjectAliphatic polyamides
dc.subjectThermal oxidation
dc.subjectChain scission
dc.subjectEmbrittlement
dc.subjectKinetic modeling
dc.titleThermal oxidation kinetics of additive free polyamide 6-6
dc.identifier.doi10.1016/j.polymdegradstab.2012.11.002
dc.typdocArticle dans une revue avec comité de lecture
dc.localisationCentre de Paris
dc.subject.halChimie: Polymères
dc.subject.halSciences de l'ingénieur: Matériaux
ensam.audienceInternationale
ensam.page22-36
ensam.journalPolymer Degradation and Stability
ensam.volume98
ensam.issue1
hal.identifierhal-00984697
hal.version1
hal.statusaccept
dc.identifier.eissn1873-2321


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