Preparation Of Polyurethane/Inorganic Oxide Blend Membranes And The Studies Of O₂/N₂Permeability

The technology of O2/N2separation is widely used in many industries, such as combustion, fermentation, and medical industry. Compared with the traditional separation technology, O2/N2membrane separation technology brings us higher efficiency, simpler equipment, easier operation and lower energy consumption. Polyurethane, as new material for gas separation, is concerned with its high selectivity, but the low permeability of polyurethane membrane limits the using. The organic-inorganic blend polyurethane membrane will be developed into a new-type gas separation membrane in the future because it can improve gas permeability and selectivity at the same time.In this paper, the studies were based on polyurethane (PU) and the main research contents and conclusions can be listed below:(1)The SiO2paticles were mixed in PU matrix. The effects of contents of SiO2paticles, the hard segment contents of PU and the type of operating conditions (pressure (P), temperature (T)) on O2/N2permeability and selectivity of PU blend membranes were discussed. The blend membranes containing3wt%silica,28.97wt%hard segment showed the O2permeability and O2/N2selectivity were6.89Barrer and4.82at0.2MPa and20℃.(2) Prepared composite oxide Fe2O3-SiO2and complex particle Fe2O3/SiO2by different motheds, and added them to PU matrix. The effect of Fe2O3proportion and the contents of composite oxide Fe2O3-SiO2on O2/N2permeability and selectivity of PU blend membranes were studied. The results showed that O2permeability and O2/N2selectivity reached13.35Barrer and7.14respectively, when Fe2O3proportion is50wt%, composite oxide content is10wt%.(3) Prepared composite oxide MnO2-Fe2O3, and added it to PU matrix. Four particles (Fe2O3, MnO2, complex particle MnO2/Fe2O3and composite oxide MnO2-Fe2O3) and their PU blend membranes were researched. The effect of MnO2proportion and the contents of composite oxide MnO2-Fe2O3on O2/N2permeability and selectivity of PU blend membranes were studied. The results showed that O2permeability and O2/N2selectivity reached18.93Barrer and7.48respectively, when MnO2proportion is50wt%, composite oxide content is10wt%.Studies showed that the composite oxide has more excellent performance than single oxide. The O2/N2selectivity of PU blend membrane which containing composite oxide Fe2O3-SiO2increased by48.13%, compared with which containing SiO2. And O2/N2selectivity of PU blend membrane which containing composite oxide MnO2-Fe2O3increased by4.76%, compared with which containing composite oxide Fe2O3-SiO2, increased by55.19%compared with which containing SiO2.