科研之友
微信
新浪微博
Facebook
分享链接
摘要
This manuscript presents the gas transport properties of a series of semifluorinated poly(ether imide)(PEI) membranes containing diphenylfluorene moiety in the main chain The effect of diphenylfluorene moiety towards four gases (e g. CO(2), O(2), N(2) and CH(4)) at three different temperatures (35, 45 and 55 degrees C) under an applied upstream pressure of 3.5 bar has been examined The membranes were prepared by thermal imidization of the poly(amic acid)s, reaction products of a diphenylfluorene containing semifluorinated diamine monomer, 4,4'-bis-((2'-trifluoromethyl-4'-(4 ''-aminophenyl) phenoxy)-9-fluorenylidene (FBP) with five different commercial dianhydrides namely, PMDA. BTDA, 6FDA, ODPA, and BPADA in DMF All these polymeric membranes showed higher gas permeability with comparable permselectivity The polymer FBP-6FDA and FBP-BTDA showed better separation efficiency in comparison to many other FBP containing polymeric membrane of different classes (e.g., polysulfones, polycarbonates, polyacrylates, poly(ether ketone)s, poly(arylene ether)s, poly(arylene ether ketone)s etc) reported earlier. Moreover highest ideal CO2 permeability of 53 09 Barrer with highest permselectivity (39 62 for CO(2)/CH(4)) of the FBP-6FDA membrane containing hexafluoro-isopropylidene group made this polymer interesting for gas separation purpose among the entire diphenylfluorene based polymeric membrane investigated so far This FBP-6FDA membrane also showed the highest permeability for 02 (13 46 Barrer) with ideal permselectivity of 6.53 whereas FBP-BTDA also showed similar ideal permselectivity of 6.57 for O(2)/N(2) gas pair but with lower permeability value (6.24 Barrer) The effect of temperature on the gas transport properties of these membranes was also studied The activation energies for gas permeation and diffusion processes were calculated from the corresponding Arrhenius plots.
- 出版日期2010-10-15
