High pressure phase equilibria in the systems linear low density polyethylene + n-hexane and linear low density polyethylene + n-hexane + ethylene: Experimental results and modelling with the Sanchez-Lacombe equation of state

摘要: Abstract Cloud point isopleths, bubble-point isopleths and liquid–liquid–vapour bubble were measured for a binary system of linear low density polyethylene (LLDPE) n-hexane the ternary LLDPE + n-hexane + ethylene. The experiments performed according to synthetic method in temperature range 400–500 K at pressures up 14 MPa. LLDPE used was hydrogenated polybutadiene almost monodisperse (Mw/Mn = 1.19). Measured experimental data LLDPE + n-hexane LLDPE + ethylene taken from literature [H. Trumpi, Th.W. de Loos, R.A. Krenz, Heidemann, High pressure phase equilibria polyethylene + ethylene: results modeling, J. Supercrit. Fluids 27 (2003) 205–214.] modelled with modified Sanchez-Lacombe equation state. same sample both experiments. parameters found by performing sequence non-linear regressions on pressure–volume–temperature reference molten cloud systems LLDPE + ethylene. From this information fit n-hexane + ethylene behaviour LLDPE + n-hexane + ethylene can be predicted. Using procedure influence ethylene concentration is slightly under Therefore, LLDPE–ethylene interaction parameter adjusted LLDPE + hexane + ethylene data. In way gives very good description curves an quantitative prediction boundary curves.