Preparation and application of microporous TPX membranes

In the present work, poly(4-methyl-1-pentene) (TPX) was used to prepare hydrophobic microporous membranes, and the application of the prepared membranes to pervaporation and osmotic distillation was also investigated. The TPX/cyclohexane solution inclines to undergo solid-liquid demixing and form polymer particles at room temperature. The solid-liquid demixing is strongly related to the crystallization process. During membrane formation, the competition between solid-liquid demixing and polymer precipitation determines if particulate membranes can be prepared. By using suitable coagulant, such as propanol, the solid-liquid demixing process occurs before polymer precipitation, particulate TPX membranes with interconnected pores can thus be successfully fabricated. By adjusting the coagulation environment, the pore size of the porous TPX membrane can be tailored. Experiments were performed to evaluate the performance of the prepared membranes in pervaporation and osmotic distillation. The results indicate that the performance of the microporous TPX membranes prepared in the present work is comparable to the commercial PTFE membranes.