Naslov
An improved apparatus for vapour–liquid equilibria measurement in polymer + solvent systems at higher temperatures: a study of the water + poly(ethylene glycol) system

Autori
Pavlíček, Jan ; Bogdanić, Grozdana ; Wichterle, Ivan

Izvornik
Fluid phase equilibria (0378-3812) 454 (2017); 111-115

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
correlation ; experimental data ; polymer–solvent system ; static cell ; vapour–liquid equilibrium

Sažetak
Recently we designed an apparatus for total pressure measurement in binary polymer + solvent systems. Accurate as it is, the apparatus is limited by its direct capacitance pressure sensor that can operate only at 318.15 K. In this study we tested a new setup that overcomes this limitation with a pressure transducer (MKS Baratron), which can be heated up to 430 K. The main improvement is that the new setup has eliminated solvent vapour condensation in the pressure measurement unit. Other parts of the equipment can easily be kept at temperatures higher than the system temperature with heating tapes. Unlike the ebulliometric method, which is limited by problems arising from the boiling of viscous mixtures, now we can study solutions with higher polymer concentrations. We tested the new setup by measuring the total pressure of binary poly(ethylene glycol) + water mixtures at six isotherms in the (308.15–343.15) K range. Additionally we determined new data for three isotherms (343.15, 353.15, and 363.15) K using ebulliometric method. We then correlated our measurements with both methods using the UNIQUAC–free volume model and compared them with available published data for isotherms 313.15 K and 333.15 K. The agreement with our static measurement results was excellent.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne tehničke znanosti

POVEZANOST RADA