制备了一系列HTBN/PAN复合膜,用于渗透汽化脱除正庚烷/乙硫醚/正丁硫醇混合物体系中的乙硫醚和正丁硫醇,此复合膜优先脱除乙硫醚和正丁硫醇.通过扫描电子显微镜(SEM)对复合膜的表面和断面进行表征.考察了复合膜在正庚烷和正庚烷/乙硫醚/正丁硫醇混合物体系中的溶胀性以及复合膜在长时间操作下的稳定性,研究了膜液浓度对膜结构和膜分离性能的影响以及操作温度对膜分离性能的影响.结果表明:交联的HTBN在PAN多孔膜表面形成均匀致密的分离层;膜在正庚烷及正庚烷/乙硫醚/正丁硫醇混合物体系中的溶胀度均小于5%;操作温度对于膜的富硫因子影响不大,而渗透通量则随着温度的升高而增大;对于正庚烷/乙硫醚/正丁硫醇混合物分离体系(含硫量为160μg/g),在80℃,50 h长时间操作下,HTBN/PAN复合膜的渗透通量为0.23 kg/(m2.h),富硫因子为2.85.
A serial of HTBN/PAN composite membranes were prepared for removing diethyl sulfide and n-butanethiol from n-heptane/diethyl sulfide/n-butanethiol mixtures by pervaporation.The surface and profile morphologies of composite membranes were investigated by SEM.The swelling degree and the stableness of the composite membranes were studied in long operation period.In addition,the effects of HTBN concentration in membrane dopes on the composite membranes' structures,the effects of HTBN concentration and operation temperatures on pervaporation performances of the HTBN/PAN composite membranes for the separation of n-heptane/diethyl sulfide/n-butanethiol mixtures were also studied.The SEM characterization results indicated that a dense layer of crosslinked hydroxyl-terminated polybutadiene(HTBN) was formed on the surface of the microporous polyacrylonitrile(PAN) membrane;The maximum of the swelling degree of the membrane in n-heptane and n-heptane/diethyl sulfide/n-butanethiol mixtures was both no more than 5%;With increasing the operation temperatures,the sulfur-enrichment factor almost stay the same but the permeated fluxes increased sharply;The HTBN/PAN composite membranes had a flux of 0.23 kg/(m2·h) and sulfur-enrichment factor of 2.85 for diethyl sulfide and n-butanethiol in the n-heptane/diethyl sulfide/n-butanethiol mixtures(the sulfur concentration was 160 μg/g) at 80 ℃ during the 50h long time operation of pervaporation.