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	Provedor de dados ArchiMer (4) Autor Roux, Gerard (4) Davies, Peter (3) Fayolle, Bruno (3) Le Gac, Pierre-yves (3) Verdu, Jacques (3) Aragon, Emmanuel (1) Belec, Lenaik (1) Celina, Mathew (1) Le Gac, Pierre Yves (1) Nakache, Maryline (1) Perrin, Francois-xavier (1) Mais... Palavra-chave Polychloroprene (3) Ageing (2) Oxidation (2) Cathodic delamination (1) Clustering (1) FTIR (1) Kinetic modeling (1) Kinetics (1) Modulus changes (1) Radical chain (1) Rubber to metal systems (1) Sulfur vulcanization (1) Water sorption (1) Mais... Tipo do documento Text (4) Ano 2016 (1) 2014 (2) 2011 (1) País France (4) Idioma Inglês (4)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 4 Primeira ... 1 ... Última Degradation of rubber to metals bonds during its cathodic delamination, validation of an artificial ageing test ArchiMer Nakache, Maryline; Aragon, Emmanuel; Belec, Lenaik; Perrin, Francois-xavier; Roux, Gerard; Le Gac, Pierre-yves. Rubber-metal assemblies used for submarine applications are often associated to cathodic protection which can lead to cathodic disboncling of the polymer/metal interface. The degradation mechanisms of polychloroprene/epoxy adhesive/copper-aluminium substrate systems associated to an accelerated ageing test are compared to the degradations resulting from natural ageing conditions in the Mediterranean sea. From destructives tests, a kinetic in four steps is identified for both ageing conditions. This kinetic is confirmed by Electrochemical Impedance Spectroscopy data during ageing. In order to further identify the failure mode, the disbondecl surfaces on polymer and steel sides are analyzed using SEM and FTIR. Both ageing conditions present the same type of... Tipo: Text Palavras-chave: Ageing; Rubber to metal systems; Cathodic delamination; FTIR. Ano: 2011 URL: http://archimer.ifremer.fr/doc/00056/16697/14370.pdf Oxidation of unvulcanized, unstabilized polychloroprene: a kinetic study ArchiMer Le Gac, Pierre Yves; Roux, Gerard; Verdu, Jacques; Davies, Peter; Fayolle, Bruno. Thermal oxidation in air at atmospheric pressure, in the 80-140°C temperature range and in oxygen at 100°C in the 0.02-3 MPa pressure range, of unvulcanized, unstabilized, unfilled polychloroprene (CR) has been characterized using FTIR and chlorine concentration measurement. The kinetic analysis was focused on double bond consumption. A mechanistic scheme involving unimolecular and bimolecular hydroperoxide decomposition, oxygen addition to alkyl radicals, hydrogen abstraction on allylic methylenes, alkyl and peroxyl additions to double bonds and terminations involving alkyl and peroxy radicals was elaborated. The corresponding rate constants were partly extracted from the literature and partly determined from experimental data using the kinetic model... Tipo: Text Palavras-chave: Polychloroprene; Oxidation; Radical chain; Kinetics. Ano: 2014 URL: http://archimer.ifremer.fr/doc/00199/31010/29413.pdf Predictive ageing of elastomers: Oxidation driven modulus changes for polychloroprene ArchiMer Le Gac, Pierre-yves; Celina, Mathew; Roux, Gerard; Verdu, Jacques; Davies, Peter; Fayolle, Bruno. The oxidative ageing in the range of 60 °C–140 °C of sulfur vulcanized polychloroprene has been studied by FTIR spectroscopy (double bond consumption), modulus changes and oxygen absorption measurements. Experiments were carried out on thin films and thick samples to investigate both homogeneous and inhomogeneous (diffusion controlled) oxidation with the goal of establishing the underlying correlation between oxidative degradation chemistry and mechanical property changes. A correlation between oxidatively driven degradation chemistry and modulus is possible using the established approaches of rubber elasticity where an effective crosslinking yield due to double bond reactions is of the order of 30% for this material (i.e. the loss of 3 double bonds... Tipo: Text Palavras-chave: Polychloroprene; Ageing; Sulfur vulcanization; Oxidation; Kinetic modeling; Modulus changes. Ano: 2016 URL: http://archimer.ifremer.fr/doc/00342/45323/44784.pdf Water clustering in polychloroprene ArchiMer Le Gac, Pierre-yves; Roux, Gerard; Davies, Peter; Fayolle, Bruno; Verdu, Jacques. Water sorption has been studied gravimetrically for polychloroprene rubber samples, first at a fixed hygrometric ratio (98% HR) and several temperatures (25, 40, 60 and 80°C) for samples of 1.9 and 3.8 mm thickness (Constant Temperature and Hygrometry, CTH experiments), then at fixed temperature (40°C) and several hygrometric ratios ranging from 0 to 95% HR on samples of 0.1 mm thickness (DVS experiments). CTH experiments reveal an abnormal sorption behavior: after an apparently fickian transient period, the water absorption continues at almost constant rate, no equilibrium is observed after more than 2500 hours, whatever the temperature. DVS experiments reveal a very low Henry’s solubility but the formation of clusters at water activities higher than 40%.... Tipo: Text Palavras-chave: Polychloroprene; Water sorption; Clustering. Ano: 2014 URL: http://archimer.ifremer.fr/doc/00188/29903/28350.pdf Registros recuperados: 4 Primeira ... 1 ... Última

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