NAMS 2002 Workshop - ICOM 2008

Packaging and Barrier Materials – 1 – Keynote
Friday July 18, 2:15 PM-3:00 PM, Wai’anae
New Developments in the Measurement of Multi-Component Sorption in
Barrier Polymer Materials: A Key Step towards the Modeling of Fuel Tank
Permeability
A. Jonquieres (Speaker), Nancy Universite, Nancy, France -
Anne.Jonquieres@ensic.inpl-nancy.fr
R. Clement, Nancy Universite, Nancy, France
C. Kanaan, Nancy Universite, Nancy, France
B. Brule, Arkema, Serquigny, France
H. Lenda, Nancy Universite, Nancy, France
P. Lochon, Nancy Universite, Nancy, France
For different reasons including safety and weight reduction of vehicles, most of
the fuel tanks are currently made of multi-layer barrier polymer materials which
have to comply with ever more demanding environmental international
regulations [1]. These fuel tanks are so poorly permeable that the measurement
of their permeability usually requires almost one year, i.e. the time necessary to
reach the steady state in contact with the multi- component fuel mixture. In this
highly demanding context, the modelling of their permeability would allow to
bypass the measurement delay and to predict and optimize their permeation
properties, within a period of time compatible with the fast evolution of the
international regulations limiting the fuel emissions per vehicle.
According to the sorption-diffusion model [2], the permeation of a fuel mixture
through of a barrier polymer film involves two elementary steps. In the first
sorption step, a part of the fuel mixture is absorbed at the upstream side of the
film. In the second step, the absorbed species diffuse across the polymer film
according to their activity gradients defined by the sorption step. Therefore,
determining the sorption properties of the different barrier polymer materials of
fuel tanks is truly indispensable for modelling their permeability [3].
However, the barrier polymer materials used in fuel tanks are usually
characterized by very low sorption levels which can nevertheless vary by several
orders of magnitude depending on the absorbed solvent. Therefore,
quantitatively determining their sorption properties remains a true technical
challenge never taken up to the best of our knowledge. This communication
describes our last progress made in collaboration with the worldwide chemical
company Arkema for the quantitative determination of these multi-component
sorption properties.
A new semi-automated desorption experimental set-up was thus developed for
measuring the sorption properties of these barrier polymer materials in contact