Copolymers from 1-(3,3,3-Trifluoropropyldimethylsilyl)-1-propyne and 1-Trimethylsilyl-1-propyne as Membrane Materials for the Separationof Gas Mixtures Containing Hydrocarbons
AbstractIn this study fluorine-containing copolymers from 1-trimethylsilyl-1-propyne and its F-containing analog – 1-(3,3,3-trifluoropropyldimethylsilyl)-1-propyne of different composition and geometric structure were obtained. The produced polymers combine resistance to hydrocarbons of different types with high permeability coefficients and high selectivity of n-butane separation from its mixture with non-condensable hydrocarbon – methane. High micro porosity of the copolymers is confirmed by the results of pore volume and pore surface area investigation by low-temperature sorption of nitrogen and the investigation of film surface via atomic force microscopy (AFM). Polymer micro porosity, which has an effect on transport properties of the copolymers is determined by both copolymer composition and its microstructure, which is formed at the stage of polymer synthesis via particular catalyst system. Particularly, copolymers produced by TaCl5–Ph3Bi catalyst exhibit greater pore size and larger pore surface area, compared to copolymers with similar TMSP content, formed by NbCl5–Ph3SiH system. The high gas-transport parameters of the obtained copolymers as well as their selectivity of hydrocarbon vapor separation from gas mixtures together with high resistance against hydrocarbons make them promising membrane materials to be used, for example, in processes of natural gas conditioning or the separation of C3+ hydrocarbons from associated petroleum gas.