加成型硅橡胶复合膜的制备及渗透汽化性能研究

Research of the preparation and pervaporation of addition silicon composite membrane

制备了以聚偏氟乙烯(PVDF)微滤膜为底膜的加成型硅橡胶聚二甲基硅氧烷(PDMS)复合膜,用于渗透汽化分离乙醇/水体系。通过改变膜液的固含量和配比研究了复合膜的成膜性,采用扫描电镜(SEM)表征了复合膜的形貌结构,测定了交联PDMS均质膜的平均交联链长度、凝胶含量、溶胀度和溶解选择性,考察了配比和操作温度对复合膜渗透汽化性能的影响。结果表明:当含氢硅油中氢与乙烯基硅油中乙烯基的摩尔比为2∶1时,操作温度为50℃,料液浓度为10%(质量分数)时,复合膜的分离因子最高为8.9,渗透通量为124g/(m^2·h)。

The addition silicon composite membranes supported by polyvinylidene fluoride（PVDF）porous microfiltration membranes were prepared and applied for ethanol recovery from ethanol/water system by pervaporation.The film-forming property of membranes was regulated by changing reaction conditions such as the H：vinyl molar ratio and solid content of membrane solution,and the morphology of PDMS/PVDF composite membranes were characterized by SEM.The average crosslinking chain length,gel content,swelling degree and selective sorption selectivity of PDMS homogeneous membranes were measured and the effect of molar ratio and the operation temperature on pervaporation of membranes were studied.It was found that when the molar ratio of H∶vinyl was 2∶1,with operation temperature of 50℃ and 10wt% ethanol feed concentration,the separation factor of membrane reached the maximum value of 8.9 with total flux of 124g/（m^2·h）.