Separation of tetrahydrofuran using RSM optimized accelerator-sulfur-filler of rubber membranes: Systematic optimization and comprehensive mechanistic study

摘要

Response surface methodology (RSM) optimized, semi efficiently vulcanized (SEV) and filled organophilic composite natural rubber (NR) membranes of varying physichochemical interactions were reported for sorption-diffusion-permeation based separation of tetrahydrofuran (THF) from binary aqueous mixtures. RSM was used to obtain optimum accelerator/sulfur (A/S) ratio required for crosslinking of nine membranes to find excellent balance of mechanical properties. These membranes were characterized by FESEM, AFM, EDX, XRD, DTG, TGA, DSC and FTIR. Vulcanized products formed from several crosslinking precursors of NR via radical and/or ionic paths were incorporated to impart an unambiguous reaction mechanism. RSM was also used to obtain optimum conditions (temperature/concentration/filler) for total flux (TF) and separation factor (SF). Membrane intrinsic properties, like partial permeabilities (PPs), selectivities and diffusion coefficients (DCs) were also studied. NRSEV12 membrane showed excellent balance of TF (24.01 +/- 0.7 g m(-2) h(-1)) and SF (118.8 +/- 4.16) at 0.97 wt% of THF in feed and 35 A degrees C.