非织造布结构对PVC–C/PET复合膜的结构与性能影响

Effect of Non-woven PET Fabrics with Different Microstructure on the Structure and Properties of PVC–C/PET Composite Membranes

以PVC-C为成膜聚合物,N,N-二甲基乙酰胺(DMAc)为溶剂,以聚对苯二甲酸乙二酯(PET)非织造布为支撑层,将凝固涂层工艺与非溶剂诱导相分离法相结合,制备了PVC-C/PET复合多孔膜。通过接触角测量仪、场发射扫描电子显微镜、孔径分布、孔隙率、纯水通量、碳素墨水截留、拉伸试验等系统研究了非织造布结构对PVC-C/PET复合膜孔结构和渗透性能的影响。结果表明,采用密度小、结构疏松的PET非织造布作为PVC-C微孔膜的支撑材料,制得的PVC-C/PET复合膜表面开孔程度增加,内部海绵状结构更疏松,孔隙率增大,降低了跨膜阻力,纯水通量从88.49 L/(m2·h)提高到186.85 L/(m2·h),与原膜相比提高了211.1%。此外,PVC-C/PET复合膜具有良好的截留性能,对碳素墨水截留率均保持99%以上,同时复合膜的拉伸强度和断裂伸长率明显增大。

The chlorinated polyvinyl chloride(PVC-C)porous membrane was fabricated on the polyethylene terephthalate(PET)non-woven fabric by non-solvent induced phase separation(NIPS)combined with coagulation coating process.The properties of non-woven fabric and PVC-C/PET composite membranes were evaluated from pure water contact angle,field emission scanning electron microscope(FESEM),pore size distribution,porosity,pure water flux,carbon ink rejection and tensile testing.The forming mechanism of PVC-C/PET composite membranes was investigated according to the effects of non-woven fabric microstructure.The results indicate using PET nonwovens with low density and loose structure as the support material of PVC-C microporous membrane,the surface opening degree of PVC-C/PET composite membrane is increased,the internal sponge structure is more loose,the porosity is increased,and the cross membrane resistance is reduced.The PVC-C/PET composite membranes obviously exhibited higher pure water flux of 186.85 L/(m2·h),which is increased by 211.1%compared with the membrane without support layer[88.49 L/(m2·h)].The rejection to ink suspension is over 99%.Furthermore,the tensile strength and elongation at break of composite membrane is also greatly improved on account of the special microstructure of non-woven fabric.