Gas transport through poly (trifluoropropylmethylsilicone) / polyetherimide composite membrane

摘要

Poly (trifluoropropylmethylsilicone) is well known for its oleophobicity, hydrophobicity and extending upper service temperature except for maintaining usual properties of conventional silicone polymers. Novel composite membranes have been fabricated with PTFPMS as a selective layer on microporous polyetherimide (PEI) support membranes. The gas permeation rate through the composite membrane decreased in the order of CO2 >H2 >O2 >N2. The permeation rates of O2, N2 and H2 were independent with pressure difference, while the permeation rate of CO2 had distinct decrease under 0.1MPa pressure difference then appeared slight increase as further increasing pressure difference to 0.4MPa. At 20 °C and 0.06 Mpa, the permeation rate of oxygen through the composite membrane was 22.4 GUP (1 GUP= 1×10 -6 cm 3 (STP)/cm 2 ·s·cmHg), the ideal selectivity of O2/N2 and CO2/N2 was 3.2 and 18.3 respectively. Solvent resistance test conducted in isooctane and petroleum ether verified that the composite membrane could remain its stable gas separation performance.