Enhanced PEBA composite membrane performance by solution-free melt coating for phenol pervaporation from aqueous solution

Solution-based membrane fabrication methods, which are widely used in the membrane industry, have a negative impact on the environment and fabrication effectiveness. In this study, a green solution-free melt coating method was proposed to rapidly fabricate a poly(ether-block-amide) copolymer (PEBA) composite membrane. Based on its melting point and viscosity, PEBA 1074 was chosen as a suitable membrane material for fabrication by solution coating and melt coating methods, which were compared by characterizations such as variable-temperature synchrotron X-ray diffraction and nano-scratching test to reveal the differences in such as crystallinity etc. The separation performance of these membranes for the pervaporation of phenol from aqueous solutions under different operating conditions was evaluated. The results showed that the PEBA composite membrane fabricated by the melt coating method possessed the same separation factor as the corresponding freestanding membrane because the sol-gel transition was avoided, and a separation factor of 74 for the separation of 1.5 wt% phenol/water solution at 70 °C can be obtained due to high density and crystallinity even with a thickness of 11 μm, which is superior to previously reported results. This study provides an ecologically friendly and effective approach for the fabrication of thermoplastic polymer membranes, thereby promoting their industrial applications.