Preparation of poly(dimethylsiloxane), poly(siloxane-urethane) and poly(phenylene oxide) membranes for gas separation and pervaporation

Studies on the formation of poly(dimethylsiloxane) (PDMS), poly(siloxane-urethane) and poly(phenylene oxide) (PPO) membranes and their properties in gas separation and pervaporation have been presented. Dense symmetric membranes were initially formed in the early stages of the studies. In the next stage of the membrane development, active polymeric layers were cast directly on commercially obtained porous ceramic or polymer supports. The properties of the obtained membranes were then evaluated in the separation of a model gaseous mixture comprising CO2 (17 %), O-2 (5 %) and N-2 (78 %) as well as in the vacuum pervaporation of aqueous solutions of acetone (5-10 wt %) at 50 C. Depending on the type of membrane and process parameters, permeates containing 40-60 % CO2 were obtained with the application of PDMS and poly(siloxane-urethane) membranes. 26-35. % CO2 content was achieved in permeates in the case of PPO-derived membranes. The permeates obtained from pervaporation tests contained 50-84 wt % acetone, while the separation factor (3 was found to be between 20-57 depending on the type of membrane and the concentration of the feed.