High pressure solubility data for carbon dioxide in polymerized ionic liquids using a magnetic suspension balance: P[VBTMA][BF4] and P[VBMI][BF4]

I&EC 135

Andre Blasig, ablasig@uwyo.edu1, Jianbin Tang, Jianbin@uwyo.edu1, Xudong Hu, huxudong@uwyo.edu2, Youqing Shen, sheny@uwyo.edu2, and Maciej Radosz2. (1) Department of Chemical and Petroleum Engineering, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071, (2) Soft Materials Laboratory, Department of Chemical and Petroleum Engineering, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071
Solubility measurements were conducted via a magnetic suspension balance for carbon dioxide in polymers synthesized from ionic liquids, poly(p-vinylbenzyltrimethyl ammonium tetrafluoroborate), P[VBTMA][BF4] for short, and poly(1-(p-vinylbenzyl)-3-methyl-imidazolium tetrafluoroborate), P[VBMI][BF4] for short, at 25, 50, and 75 °C and up to 180 bar. The accurate performance of the magnetic suspension balance was verified by comparing our CO2 solubility data for bisphenol-A polysulfone with literature data. At low pressures (up to 15 bar) the solubility data for all three polymer–gas systems show typical glassy behavior modeled with a dual-mode sorption model. At high pressures (up to 180 bar) the apparent solubility of the two ionic polymers approaches asymptotic values. Pressure DSC data obtained for either ionic polymer show that each ionic polymer remains glassy when exposed to CO2 at pressures up to 70 bar. The CO2 solubility in the P[VBTMA][BF4] is higher than that in bisphenol-A polysulfone at the same temperature and pressure.