Moisture sorption in polyamide 6.6: experimental investigation and comparison to four physical-based models
|Author(s)||Broudin Morgane1, 3, Le Saux V.1, Le Gac Pierre-Yves2, Champy C.3, Robert G.4, Charrier P.3, Marco Y.1|
|Affiliation(s)||1 : Univ Brest, ENIB, ENSTA Bretagne, Lab Brestois Mecan & Syst,EA 4325, F-29806 Brest 9, France.
2 : Ctr Brest, IFREMER French Ocean Res Inst, Mat & Struct Grp, F-29280 Plouzane, France.
3 : TrelleborgVibracoust, F-44474 Carquefou, France.
4 : Technyl Innovat Ctr Simulat & Validat Applicat, Solvay Engn Plast, F-69192 St Fons, France.
|Source||Polymer Testing (0142-9418) (Elsevier Sci Ltd), 2015-05 , Vol. 43 , P. 10-20|
|WOS© Times Cited||25|
|Keyword(s)||Polyamide 6.6, Water sorption, Temperature, Relative humidity, Physically-based models|
|Abstract||Water sorption in polyamide 6.6 has been characterized for a wide range of temperature (25°C to 80°C) and various water activities using a Dynamic Vapor Sorption testing machine. Complex sorption mechanisms govern the water uptake in the material. The competition between two main temperature dependant mechanisms has been observed: a Henry’s sorption mechanism that mainly governs the sorption curve at low water activities, and a second mechanism at high water activities that could be related to the formation of water clusters. It is observed that the temperature dependency can mainly be attributed to the Henry’s contribution. Four physically based models are then used and identified thanks to the extended experimental database. It is shown that a simple Flory-Huggins model is not able to capture the experimental observations at very high water activities for all the temperatures tested. The ENSIC model is a better choice, but good prediction for very high water activity cannot be obtained. Both modified Park and GAB models can accurately predict the volume fraction of water for the whole ranges of water activity and temperature, although the modified Park model should be preferred considering the number of parameters and the mathematical simplicity.|