Reuse of reclaimed tire rubber for gas-separation membranes prepared by hot-pressing

Waste tires are mainly composed of natural rubber, synthetic rubber, carbon black, steel wires, and fibers. Rubber, which is a valuable resource, is one of the raw materials used for membrane preparation. In this study, a convenient and environmentally friendly synthetic technology, hot-pressing method was developed for reusing reclaimed tire rubber to prepare gas-separation membranes. The effects of the preparation conditions, including hot-pressing temperature, pressure, and time on the membrane structure and separation performance, were investigated. Thermogravimetric analysis and field-emission scanning electron microscopy were carried out. The Thermogravimetric analysis, Fourier-transform infrared spectroscopy, and cross-linking degree results showed that the reclaimed tire rubbers used in this study consisted mainly of styrene-butadiene rubber and polybutadiene rubber. Reclaimed tire rubbers with low carbon contents and low degrees of cross-linking are beneficial for fabricating membranes by hot-pressing. The hot-pressing technique proposed in this study yielded dense gas-separation membranes from the reclaimed tire rubbers, proved to be an efficient approach for simplified recycling of waste tires and can in fact inspire the development of new recycling routes. The hot-pressed membranes derived from reclaimed tire rubber showed competitive results with a CO2/N2 selectivity of 12.8 and CO2 permeability of 161 Barrer. [Display omitted] •Hot pressing was developed as a new synthetic technology for membrane fabrication.•Reclaimed tire rubbers was recirculated into the gas membrane by hot-pressing.•Reclaimed tires derived membranes showed ideal CO2/N2 separation performance.