Prediction of solubilities for volatile hydrocarbons in low‐density polyethylene using UNIFAC‐FV model

The UNIFAC‐FV model has been applied to predict the weight‐fraction Henry's constant of n‐hexane, n‐octane, benzene, and toluene in low‐density polyethylene in the region 124 to 250°C. By adjusting the number of external degrees of freedom per hydrocarbon molecule, the weight‐fraction Henry's constant was correlated with good agreement by the model. Namely, the solubilities of hydrocarbons in the polymer can be obtained correctly from the model at low pressures, less than 2 atm. Although the model is very useful, its applicability is limited to the subcritical temperature range of a volatile hydrocarbon.