Preparation of ultrafiltration membrane from discarded polyethylene terephthalate bottles

In this study, the polymeric membranes were prepared using discarded polyethylene terephthalate (PET) bottles. The fabrication of the membrane process was carried out using a dope solution composed of polyethylene terephthalate (polymer), O-cresol (as a solvent), and polyethylene glycol 400 (as an additive). The solubility parameters were studied to dissolve the polymer into the solvent at a specific temperature. The melt flow index and thermal analysis were evaluated for the discarded bottles and prepared membranes to ensure the quality and thermal stability of the PET. The porosity of the membranes was determined using scanning electron microscopy. The temperature required to prepare the dope solution was 80 °C with a stirring speed of 350 rpm. Non-solvent-induced phase separation method was used to fabricate the membranes. The coagulation bath was composed of a water-ethanol mixture. The porosity of the prepared membranes ranges between 30 and 50%. The contact angle was determined for the membrane in the range of 40° to 80°. The flux of the membranes was evaluated using membrane testing cell at a specified pressure which ranges from 80 to 150 Lm^-2 h^-1. The prepared membranes could be used in various industries like dairy, pharmaceutical, juice, and beverages to separate temperature-sensitive substances.