A visual measurement apparatus was applied to monitor in-situ the swelling behavior of poly(methyl methacrylate) (PMMA) in supercritical carbon dioxide(scCO2).This work presents the swelling data of PMMA over a useful range of processing conditions (temperature from 305 K to 325 K
and pressure up to 24 MPa).The Sanchez-Lacombe equation of state (S-L EOS) is suitable to describe low molecular weight solvent-polymer systems.Through fitting the PVT data into S-L EOS
the characteristic pressure
temperature and density of PMMA were regressed as 212.38 MPa
898.04 K and 1206.7 kg·m-3 (8—25 MPa
305—350 K)
respectively.Similarly
the characteristic parameters for carbon dioxide (CO2) were 541.56 MPa
313.38 K and 1502.1 kg·m-3 (8—25 MPa
305—325 K)
respectively.The equilibrium swelling data of PMMA in scCO2 were correlated with S-L EOS
the binary interaction parameter was obtained as 1.0671.These results indicated that the S-L EOS can be used to predict the solubility of CO2 and the swelling of PMMA over a wide range of pressure.The S-L EOS modeled values agreed well with the experimental data in supercritical region.