Nanoporous materials based on spiroketal and spirothioketal polymers for separating methanol-toluene mixture

Abstract

Organic microporous materials based on spiroketal and spirothioketal polymers were synthesized through 1,3-dioxol-forming polymerization reaction between pentaerythritol or pentaerythritol tetrathiol and different types of cyclohexa-1,4-dione derivatives. The structure of the prepared polymers was confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers show a large amount of nitrogen adsorbed at low relative pressure indicating microporosity. These polymers have Brunauer Emmitt and Teller (BET) surface areas in the range from 492 (m2 g−1) to 685 (m2 g−1). The prepared polymers were found to be useful for pervaporation separation of methanol-toluene mixture with a separation factor up to 12.5 and fluxes, varying between 6.7 × 10−3 kg/(m2 h) and 13.4 × 10−3 kg/(m2 h).