PMD/PVDF共混两亲中空纤维膜的制备及其性能

Preparation and properties of PMD/PVDF blends with two amphiphilic hollow fiber membranes

以甲基丙烯酸甲酯(MMA)为疏水单体,甲基丙烯酸二甲氨基乙酯(DMAEMA)为功能性亲水单体,制备出两亲性聚合物P(MMA-DMAEMA)(PMD),然后以PMD聚合物为添加剂,制备出PMD/PVDF共混两亲中空纤维超滤膜。通过凝胶渗透色谱、核磁共振和红外光谱表征两亲性聚合物PMD的分子质量及化学结构与组成,测试PMD/PVDF中空纤维超滤膜的接触角、水通量、泡点、力学性能以及抗污染性能,SEM观察膜的结构形貌。结果表明:与原膜相比,超滤膜的接触角由98.7°下降到85.3°,水通量增加246.08 L/(m2·h),泡点降低0.09 MPa,相对渗透率增加0.12,抗污染性能提高。在力学性能方面,膜的刚性提高,韧性略有下降。最大孔径增大,指状孔结构更加精细、均匀。

The amphiphilic polymer P(MMA-DMAEMA)(PMD) was prepared using methyl methacrylate(MMA) as hydrophobic monomer and dimethyl amino ethyl methacrylate(DMAEMA) as hydrophilic functional monomer. Then the PMD/PVDF blend two hydrophilic hollow fiber ultrafiltration membrane was prepared with PMD copolymer as additive. The molecular weight, chemical structure and composition of PMD were characterized by gel permeation chromatography, NMR and infrared spectroscopy. The contact angle, water flux, bubble point, mechanical properties and anti-pollution properties of PMD/PVDF hollow fiber ultrafiltration membrane were tested. The results showed that compared with the original membrane, the contact angle decreased from 98.7° to 85.3°, the flux increased by 246.08 L/(m2·h), the bubble point decreased by 0.09 MPa,the relative permeability increased by 0.12, and the anti-pollution performance improved. In terms of mechanical properties, the rigidity of the film had been improved and the toughness had decreased slightly. The maximum pore size was increased, and the finger like pore structure was more fine and uniform.