一种新型聚酰亚胺-氨酯反渗透复合膜材料的合成及表征

采用关键功能单体N,N'-二甲基间苯二胺(DMMPD)和多元酰氯5-氯甲酰氧基-异肽酰氯(CFIC)聚合制备了一种耐氧化的聚酰亚胺-氨酯(DMMPD-CFIC)反渗透复合膜材料. 研究了水相溶剂、 多元胺浓度和组成及两相接触时间等因素对DMMPD聚合成膜的影响. 结果表明, 虽然DMMPD-CFIC膜的脱盐率不够理想, 但将4-甲基间苯二胺(MMPD)与DMMPD以2∶1(质量比)组合后制得的MMPD/DMMPD-CFIC膜的脱盐率得到显著提高, 并且对膜的耐氯性能影响不大. 采用傅里叶衰减全反射红外光谱(FTIR)和X射线光电子能谱(XPS)分析了2种膜的活性层的结构, 并利用扫描电镜(SEM)和原子力显微镜(AFM)对膜的表面形态进行了表征.

Preparation and Characterization of a Novel Polyimide-urethane Reverse Osmosis Composite Membrane Material

The common aromatic polyamide composite reverse osmosis(RO) membrane is easy to be oxidated. N,N'-dimethyl-m-phenylenediamine(DMMPD) as a key functional monomer could be reacted with 5-choroformyloxyisophthaloyl chloride(CFIC) to prepare a chlorine resistance polyimide-urethane RO membrane material by interfacial polymerization technology. In this study, the membrane formation conditions such as solvent of aqueous phase, composition and concentration of amine in aqueous phase, and contact time of two phases were optimized. The results show that the NaCl rejection rate of DMMPD-CFIC membrane prepared from only DMMPD is not ideal, but the combination of DMMPD and 4-methyl-m-phenylenediamine(MMPD) at a mass ratio of 1∶2 to prepare the MMPD/DMMPD-CFIC membrane can obviously improve the NaCl rejection of the resulting membrane, and the chlorine resistance performance of membrane just has slight change. Furthermore, the surface chemical structure of membrane active layer was analyzed by combination of attenuated total reflectance infrared(ATR-FTIR) and X-ray photoelectronic spectroscopy(XPS), and the surface morphology of membrane was observed via scanning electronic microscopy(SEM) and atomic force microscope(AFM).