A Device for Determination of Vapour Sorption in Polymers
O. Vopička
Department of Physical Chemistry, Polymer Department, Institute of Chemical Technology, Prague
V. Hynek
Department of Physical Chemistry, Polymer Department, Institute of Chemical Technology, Prague
K. Friess
Department of Physical Chemistry, Polymer Department, Institute of Chemical Technology, Prague
M. Šípek
Department of Physical Chemistry, Polymer Department, Institute of Chemical Technology, Prague
P. Sysel
Department of Physical Chemistry, Polymer Department, Institute of Chemical Technology, Prague
Abstrakt
The principle of the device consists in measuring the mass of vapour sorbed in a sample as a function of time using the McBain spiral balance monitored by a camera system. Absolute pressure is monitored by a capacitance pressure gauge. The maximum amount of the sample is limited to 0.5 g and the mass change sensitivity threshold is 10 μg. The device makes it possible to measure sorption kinetics with good accuracy. As an example, the kinetics of sorption of p-xylene vapours by low-density polyethylene membrane was measured and the resulting sorption isotherm was determined.