Embrittlement of polybutylene terephthalate induced by injection molding
Article dans une revue avec comité de lecture
Embrittlement caused by injection molding was investigated on a commercial grade of Polybutylene terephthalate (PBT). The effect of temperature and residence time in the barrel on mechanical properties was studied. Results were discussed from macromolecular analysis by Gel Permeation Chromatography and crystallinity measurements by differential scanning calorimetry. It was shown that embrittlement exclusively occurs by a chain scission process in those conditions. Oxygen is shown to play a negligible role in degradation while thermolysis seems to be the main source of degradation. It was here described by a first simple kinetic model based on the beta abstraction of hydrogen at the vicinity of ester groups. A processing window was thus determined using this model and might help practitioners for processing PBT parts.
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Article dans une revue avec comité de lectureLOYER, C.; RÉGNIER, Gilles; DUVAL, V.; OULD, Y.; RICHAUD, Emmanuel (Elsevier, 2020)This paper reports the study of embrittlement of PBT submitted either to thermal or hydrolytic ageing. All changes were followed up by tensile tests, rheometry in molten state and gel permeation chromatography for molar ...
Article dans une revue avec comité de lectureLOYER, C.; REGNIER, Gilles; DUVAL, V.; RICHAUD, Emmanuel (Elsevier BV, 2021)This paper reports the hydrolysis of several PBT materials (pigmented or not). Degradation was monitored by gel permeation chromatography (chain scission), DSC (crystalline morphology), tensile test (residual mechanical ...
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On the Accuracy of Elastic Strain Field Measurements by Laue Microdiffraction and High-Resolution EBSD: a Cross-Validation Experiment Article dans une revue avec comité de lecturePLANCHER, Emeric; PETIT, Johann; MAURICE, Claire; FAVIER, Véronique; SAINTOYANT, Lucie; LOISNARD, Dominique; RUPIN, N.; MARIJON, Jean-Baptiste; ULRICH, Olivier; BORNERT, Michel; MICHA, Jean Sébastien; ROBACH, Odile; CASTELNAU, Olivier (Society for Experimental Mechanics, 2016)Determining the accuracy of elastic strain measurements in plastically deformed alloys is an experimental challenge. To develop a novel cross-validation procedure, a controlled elasto-plastic strain gradient was created ...