| In this study, melting co-polymerization of 5-sulphosalicylic acid (5SA) and caprolactam were performed to synthesize sulfonated PA6s (SPA6s). Compounds were characterized by FT-IR, TGA and DSC. SPA6-2.5 had showed the best thermal stability. SPA6s were electrospun (ES) and the optimum operation parameters were determined by orthogonal experimental:solution concentration 15 wt% in formic acid, collection distance 21 cm, voltage 30 KV and feed rate 0.0005 mm/s. Humidity was kept at 40-60% and temperature was 45℃. The relationship between fibers morphology and factors, such as 5SA contetnt, the direction of electrostatic field and the materials of collector were investigated using FE-SEM. The diameter of fibers increased with 5SA until 5SA up to 5wt%, at which the polymer solution was unspinnable. The collecting area of nozzle grounded were smaller the normal case, collector grounded. PE, as collective substrate, had obtained fibers of highly branched and interconnecting bundles though they were thinner than aluminum fibers. SEM-EDS data showed that the content of S on PE fibers were smaller than it on Al fibers, which illustrated that nonpolar materials decreased the induction of electrostatic field on free ions.SPA6 flat membranes were prepared by immersion-precipitation method. The surface chemistry and hydrophilicity of films were analyzed by FT-IR and KRUSS dynamic contact angle measuring instrument. The average pore diameter of membranes were 0.9805,0.4416 and 0.3179μm, respectively. The increase of 5SA had lead to more narrow pore size distribution, smaller average pore diameter and higher porosity of the membranes. FE-SEM images had shown that SPA6s membranes were composed by compact skin and spongy matrix. Their water contact angles were smaller than PA6’s. The water flux of film SPA6-1.25 and SPA6-2.5 were 109.5 and 135.5L·m-2·h-1, separately. Reversion rate of SPA6 membranes were better than pure PA6 membrane tested using bovine serum protein.
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