Solubility of HFC-134a, HCFC-142b, butane, and isobutane in low-density polyethylene at temperatures from 383.15 to 473.15 K and at pressures up to 3.4 MPa

The solubility of HFC-134a, HCFC-142b, butane and isobutane in molten low-density polyethylene (LDPE) has been measured with a volumetric method at pressures up to 3.4 MPa and at temperatures of 383.15, 413.15, 443.15, and 473.15 K. The solubility increased with decreasing temperature and increasing pressure. The measured solubility was correlated with the Sanchez-Lacombe equation of state (S-L EOS) and a temperature-dependent binary interaction parameter. In all cases, the calculated solubility was in reasonably good agreement with the experimental data to within an average absolute deviation of 3.0, 5.1, 7.2, and 3.5% for HFC-134a, HCFC-142b, butane and isobutane, respectively. The Henry's constants, K_p, for butane and isobutane obtained in this work were in good agreement with the literature data and Stiel's equation. A correlation for 1/K_p of fluorocarbons in LDPE was developed in terms of fluorocarbon critical compressibility factor. Average absolute deviations for the correlated 1/K_p were 2.7, 8.1, 1.3, 4.7, and 5.2% for CFC-11, CFC-12, HCFC-22, HFC-134a, and HCFC-142b, respectively.