Stability of Polydecylmethylsiloxane Based Membranes in the Separation of an ABE Fermentation Mixture: The Effect of a Perfluorinated Substituent

Abstract

Polydecylmethylsiloxane–polyperfluorooctyl methylsiloxane (PDec-PFOMS) copolymers are synthesized for the first time. NMR data are used to determine the quantitative substitution of the Si–H bond in the PDec-PFOMS. It is shown that raising the content of PFO expands the wetting angle for n-butanol. It is established that injecting the polymer with 2 mol % of PFO increases the sorption of n-butanol by a factor of 1.5. The performance of the obtained composite membranes during the separation of the ABE fermentation mixture is studied for 70 h in the vacuum pervaporation mode. It is established that introducing 2 mol % of PFO substituents raises the total membrane flow from 0.29 kg/(m² h) to 0.55 kg/(m² h). After 70 h of separation, the reduction of the total flow through the 2PFO/MFFK membrane is found to be 10% less than that of PDecMS/MFFK. The improved stability of the transport characteristics of 2PFO/MFFK testifies to the advantage of modifying PDecMS by introducing PFO to create a material resistant to clogging when separating alcohols from an ABE-fermentation mixture.