|
|
|
|
|
| Broudin, M.; Le Gac, Pierre-yves; Le Saux, V.; Champy, C.; Robert, G.; Charrier, P.; Marco, Y.. |
| Diffusion of water in polyamide 6.6 has been characterized for a wide range of temperatures (from 25 to 80 °C) and various humidities using dynamic vapor sorption machine. The decrease in glass transition temperature (Tg) has also been measured using DMA tests. As usually observed, PA66 absorbs a large amount of water (up to 5% at 90%RH) with a Fickian behavior with a diffusion coefficient that depends on water activity for all temperatures. Moreover, it appears that the diffusion coefficient for tests performed below Tg is almost independent of the water activity whereas a strong dependency is observed above Tg. This behavior is to be compared to a large decrease of Tg with the absorption of water. The increase of the water diffusion can therefore be... |
| Tipo: Text |
Palavras-chave: Water absorption; Free volume; Polyamide; Modeling. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00260/37148/35794.pdf |
| |
|
|
| Arhant, Mael; Briancon, Christophe; Burtin, Christian; Davies, Peter. |
| The composite materials used at sea are today nearly all based on thermoset resins (polyester, epoxy). However, there is an increasing number of thermoplastic matrix polymers available on the market (PP, PA, PPS, PEEK…), which offer possibilities for forming by local heating, attractive mechanical properties and the potential for end of life recycling. The aim of this study was to design, manufacture and test thermoplastic composite pressure vessels for 4500 meter depth, in order to establish a technical, economic and ecological assessment of the use of these materials to replace traditional composites underwater. First, finite element calculations have been carried out to optimize the stacking sequence with respect to the external pressure and buckling... |
| Tipo: Text |
Palavras-chave: Thermoplastic; Polyamide; Carbon fibres; Buckling; Implosion. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00476/58742/61268.pdf |
| |
|
|
| Le Gac, Pierre-yves; Arhant, Mael; Le Gall, Maelenn; Davies, Peter. |
| This paper considers the effect of water content on mechanical properties of polyamide 6 when used in a humid environment. First an experimental section presents the tensile behavior of polyamide with different amounts of water, with and without a through-thickness water gradient. Water profiles are introduced by immersion in sea water at 25 °C. The effect of testing temperature is also investigated in order to consider the influence of macromolecular chain mobility on the mechanical behavior. Then, in a second section, modelling of yield stress is proposed based on physical considerations. This can be used for life time prediction of PA6 in humid environment when plasticization is the main degradation mechanism. |
| Tipo: Text |
Palavras-chave: Yield stress; Water; Polyamide; Plasticization; Prediction. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00371/48208/48321.pdf |
| |
|
|
| Amaral,Rafael Camargo do; Santos,Mateus Castilho; Daniel,João Luiz Pratti; Sá Neto,Adir de; Bispo,Álvaro Wosniak; Cabezas-Garcia,Edward Hernando; Bernardes,Thiago Fernandes; Nussio,Luiz Gustavo. |
| The objective of this study was to evaluate the effect of covering methods on the nutritive value of corn silage and performance of dairy cows. Whole-plant corn was harvested at 340 g/kg of dry matter (DM) and ensiled for 135 d in horizontal silos covered with one of the following methods: oxygen barrier film (45-µm thick) + white-on-black polyethylene film (200-µm thick) over the oxygen barrier film (OB+WB); white-on-black polyethylene film (200-µm thick) (WB); black polyethylene film (200-µm thick) (B); or recycled black polyethylene film (200-µm thick) covered with a layer of 10 cm of sugarcane bagasse (RB+SB). Nutrient composition, fermentation profile, and yeast and mold counts in edible silages were similar across treatments. Silage temperature... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dairy cow; Film protection; In vivo digestibility; Polyamide. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982014000900471 |
| |
|
|
|
