Characterisation and Modelling of Moisture Gradients in Polyamide 6

Polymers

Hans-Georg Herrmann¹  Michael Maisl¹  Markus Stommel²  Anna Katharina Sambale² 

[1] Fraunhofer Institute for Nondestructive Testing IZFP, Campus E3 1, D-66123 Saarbrücken, Germany;Institute of Polymer Materials, Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Str. 6, D-01069 Dresden, Germany;

关键词: polyamide 6;    water sorption;    computer tomography;    reconstruction method;    concentration-dependent diffusion coefficients;    FE modelling;   

DOI  :  10.3390/polym13183141

来源: DOAJ

【 摘 要 】

Polyamide 6 (PA6) is able to absorb water from the surrounding air and bond to it by forming hydrogen bonds between the carbonamide groups of its molecular chains. Diffusion processes cause locally different water concentrations in the (component) cross-section during the sorption process, resulting in locally different mechanical properties due to the water-induced plasticisation effect. However, the water content of PA6 is usually specified as an integral value, so no information about a local water distribution within a component is provided. This paper shows a method to characterise moisture distributions within PA6 samples using low-energy computer tomography (CT) techniques and comparing the reconstructed results with a developed finite elements (FE) modelling method based on Fick’s diffusion laws with concentration-dependent diffusion coefficients. For this purpose, the ageing of the samples at two different water bath temperatures as well as at different integral water contents are considered. The results obtained by CT reconstruction and FE modelling are in very good agreement, so that the concentration distributions by water sorption of PA6 calculated by FEM can be regarded as validated.

【 授权许可】

Unknown