Abstract
Solubilities and diffusion coefficients of high-pressure gases in polymers are important in the production of polymers. This article reviews techniques to measure these properties at high pressures. The pressure decay method measures the change in the amount of a solute gas in its vapor phase with the dissolution of the gas in a polymer. This technique requires a precise measurement of pressure. The electric balance method measures the weight of a polymer sample with an electric balance installed in a high-pressure chamber. Temperatures and pressures are limited in this method. The magnetic suspension balance method is a newly developed one. An electric balance outside the high-pressure chamber and a polymer sample are connected magnetically. This method can measure the gas solubility most accurately and can be used with a wide range of temperatures and pressures. Diffusion coefficients of gases in polymers are evaluated by applying an appropriate diffusion equation to measured uptake.
