Abstract
AbstractPolyimide/polydimethylsiloxane (PI/PDMS) graft copolymers with various PDMS contents were prepared by polycondensation of PDMS macromonomer 1 with aromatic diamines and pyromellitic dianhydride followed by heating at 220°C. The PDMS content of the grafts copolymers was controlled by changing the average degree of polymerization of the PDMS macromonomer in the range between 4 and 21. Graft copolymer membranes were prepared by casting films in the poly(amic acid) stage 2 and subsequent imidation upon heating. PI/PDMS membranes thus obtained are insoluble. The permeability coefficients towards nitrogen, oxygen, hydrogen, methane and carbon dioxide were evaluated. In the region of a PDMS content above 50 wt.‐%, the oxygen permeability coefficient of a PI/PDMS graft copolymer membrane is > 10−8 cm3(STP) · cm · cm−2 · s−1 · cmHg−1. In addition, the permeability coefficient of methane is remarkably enhanced in comparison with a PI membrane. Preferential permeation of ethanol was observed through the graft copolymer membrane in the case of pervaporation of aqueous ethanol solution. Furthermore, acetone, acetonitrile and tetrahydrofuran were efficiently separated from water at any solvent/water ratio in the mixture.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.