Cloud-point pressure curves of ethylene-based terpolymers in fluid ethene and in ethene–comonomer-mixtures—Experimental study and modeling via PC-SAFT

Cloud-point pressure (CPP) curves of ethylene-methyl acrylate-vinyl acetate terpolymers, poly(E-co-MA-co-VA), in fluid ethene (E) and in E–VA monomer mixtures and of ethylene-butyl methacrylate-methacrylic acid copolymers, poly(E-co-BMA-co-MAA), in fluid E have been measured up to maximum temperatures and pressures of 540 K and 2800 bar, respectively. The polymer samples from reaction in a continuously operated stirred tank reactor are chemically homogeneous. The experimental data is compared with CPPs predicted by the PC-SAFT (perturbed chain-statistical associating fluid theory) equation of state on the basis of PC-SAFT parameters that are available for several of the underlying monomers, homopolymers and binary copolymer–ethene systems. The modeling takes polymer molecular weight into account. Even for the poly(E-co-BMA-co-MA)–E system, in which the polymer is composed of non-polar and polar moieties and of units that may interact via hydrogen bonds, CPPs are predicted in remarkable agreement with the experimental data without performing any fitting of the CPP data measured for the terpolymer–solvent system.