PC-SAFT based group contribution method for binary interaction parameters of polymer/solvent systems

Based on the PC-SAFT equation of state, a group-contribution method is developed for the determination of binary interaction parameters (kij) between polymers and solvents (GCM-kij). Applying simple geometric combination rules, the kij values can be calculated from binary interaction parameters between polymer groups and solvent groups (kps). 80 different kps values allow the calculation of a kij for polymer/solvent systems with polymers consisting of CH3, 〉CH2, 〉CH2,HDPE, 〉(CH), 〉C〈, 〉CHAr, 〉CAr and (CO)O groups and solvents containing CH3, 〉CH2, 〉(CH), 〉CH2,Cyclo, 〉(CH)Cyclo, CH2,alkene, (CH)alkene, 〉CHAr, 〉CAr, O, 〉CO and (CO)O groups. Using earlier-published group-contributions for polymer parameters (Peters et al. [2,3]) in combination with the proposed GCM-kij for polymer/solvent systems allows for predicting liquid–liquid phase equilibria, vapor–liquid phase equilibria and excess enthalpies of binary polymer/solvent and copolymer/solvent as well as ternary polymer/solvent 1/solvent 2 systems in good agreement with experimental data.