کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
639185 | 1456189 | 2006 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Synthesis and gas permeation properties of poly(diphenylacetylenes) having bulky alkyl/silyl and hydroxy groups Synthesis and gas permeation properties of poly(diphenylacetylenes) having bulky alkyl/silyl and hydroxy groups](/preview/png/639185.png)
Novel diphenylacetylene monomers 1c–h possessing tert-butyl or trialkylsilyl and siloxy groups (p-R-C6H4CCC6H4–p-OSiMe2t-Bu: 1c R = t-Bu, 1e R = SiMe3, 1g R = SiMe2t-Bu; p-R-C6H4CCC6H4–m-OSiMe2t-Bu: 1d R = t-Bu, 1f R = SiMe3, 1h R = SiMe2t-Bu) were polymerized with TaCl5–n-Bu4Sn catalyst. Monomers 1c and 1e gave high molecular weight polymers in good yields. Free-standing membranes of polymers 2c–f were fabricated by casting from toluene solution. Desilylation of membranes of polymers 2c and 2d with trifluoroacetic acid (TFA) yielded poly(diphenylacetylenes) having tert-butyl and hydroxy groups (3c and 3d). Polymers 2c–f and 2h were soluble in nonpolar solvents such as hexane, cyclohexane and toluene, while 3c and 3d were insoluble in these solvents. According to thermogravimetric analysis (TGA), 2c–f, 3c and 3d exhibited high thermal stability. The gas permeability of all the membranes in the present study was much higher than that of the corresponding polymers without bulky groups, indicating that incorporation of bulky groups into the polymers improves the gas permeability. The PCO2/PN2 permselectivity ratios of polymers 3c and 3d were 23 and 14, respectively. The CO2 permeability and CO2/N2 permselectivity of 3c and 3d were positioned above Robeson's upper bound line.
Journal: Journal of Membrane Science - Volume 282, Issues 1–2, 5 October 2006, Pages 423–429