Book Description
The Sanchez-Lacombe equation of state was used to model the sorption of high-pressure gases into solid, amorphous polymers or molten polymers. One adjustable parameter per binary pair, SL12, was used in the mixing rule to correct the deviation of the characteristic pressure of the mixture, P12*, from the geometric mean. The values of SL12 which gave the best fit of the available literature data for the carbon dioxide-polymethyl methacrylate, carbon dioxide-silicone ribber, ethylene-low density polyethylene, methane-polyisobutylene, methane-low density and high density polyethylene, and methane-polystyrene systems ranged from 0.020 to 0.194, except for the methane-low density system which had a negative value of -0.183. In all cases, the calculated sorption isotherms were in reasonably good agreement with the experimental data. The resultant swelling of polymethyl methacrylate and silicone rubber in the presence of high-pressure carbon dioxide was also well presented by the Sanchez-Lacombe equation of state. Keywords: Sorption, Swelling, Polymers, High pressure, Gases.