The Viable Fabrication of Gas Separation Membrane Used by Reclaimed Rubber from Waste Tires

Abstract

Improper disposal and storage of waste tires poses a serious threat to the environment and human health. In light of the drawbacks of the current disposal methods for waste tires, the transformation of waste material into valuable membranes has received significant attention from industries and the academic field. This study proposes an efficient and sustainable method to utilize reclaimed rubber from waste tires after devulcanization, as a precursor for thermally rearranged (TR) membranes. The reclaimed rubber collected from local markets was characterized by thermogravimetric analyzer (TGA) and Fourier transfer infrared spectroscopy (FT-IR) analysis. The results revealed that the useable rubber in the as-received sample amounted to 57% and was classified as styrene–butadiene rubber, a type of synthetic rubber. Moreover, the gas separation measurements showed that the C7-P2.8-T250 membrane with the highest H2/CO2 selectivity of 4.0 and sufficient hydrogen permeance of 1124.61 GPU exhibited the Knudsen diffusion mechanism and crossed the Robeson trade-off limit. These findings demonstrate that reclaimed rubber is an appealing, cost effective, and sustainable alternative, as a precursor for TR membranes, for application in gas separation. The present approach is useful in the selection of a suitable reclaimed rubber precursor and related membrane preparation parameters, leading to the advancement in the recycling value of waste tires.