聚氨酯脲和聚氨酯酰亚胺膜的制备与渗透汽化芳烃/烷烃分离性能研究

Preparation of polyurethaneurea and polyurethaneimide membranes and their pervaporation performances to aromatic/aliphatic hydrocarbon mixtures

通过两步聚合的方法,成功制备了以聚己二酸乙二醇酯(PEA)为软段的聚氨酯脲(PUU)和聚氨酯酰亚胺(PUI)膜材料,用FT-IR,NMR和DSC等方法对两种膜材料的分子结构及性质等进行了表征,并考察了两种膜对芳烃/烷烃混合物的渗透汽化分离性能.结果表明,两种膜都对芳烃表现出良好的选择渗透性,在相同的条件下,PUU膜的渗透通量比PUI膜更大而分离因子更小.对于苯的浓度为50%的苯/环己烷混合物分离体系,45℃时PUI膜的渗透通量为18.6kg·μm/(m2.h),分离因子为7.3;而对于苯/正己烷混合物分离体系,渗透通量则为22.4kg·μm/(m2.h),分离因子为15.2.

Two kinds of polyurethaneurea （PUU） and polyurethaneimide （PUI） membranes materials were suecessfully synthesized with the same soft segment of poly（ethylene adipate）diol （PEA） via a two - step method. The structures and properties of PUU and PUI membranes were characterized by means of FT-IR, NMR＇ DSC and SEM. Their pervaporation performances to aromatic/aliphatic hydrocarbon mixtures were also investigated. The results appeared that the PUU and PUI membranes showed permeability and selectivity towards benzene. The PUU membranes obtained higher flux and lower separation factor than PUI under the same PV condition. The PUI membranes had a flux of 18.56 kg·μm/（m^2·h） and separation factor of 7.25 for 5096 ben： zene in the benzene/cyclohexane mixture at 45℃. In addition, they had a flux of 22.44 kg·μm/（m^2·h） and separation factor of 15.22 for 50% benzene in the benzene/n -hexane mixture at 45℃.