Facile synthesis of CO2-selective membrane derived from butyl reclaimed rubber (BRR) for efficient CO2 separation

Abstract

Butyl reclaimed rubber (BRR) was used as a novel precursor in the fabrication of a rubber membrane for CO2 separation. Fully de-vulcanized BRR without impurities was produced from waste tire by regeneration. The properties of BRR were evaluated via systematic investigation of a number of experimental variables, and the effects of these variables on the molecular structure and the CO2 separation performance of the membrane were assessed. The BRR-derived membrane was fabricated by simple solution-coating on an Al2O3 support. The effect of the fabrication parameters, such as the solvent type, polymer concentration (8–12 wt%), and curing temperature (room temperature to 100 °C). The results indicate that the CO2/N2 separation performance of the BRR-derived membrane prepared with a low concentration (<10 wt%) of coating dope in toluene solvent and cured at room temperature is competitive with that of membranes reported in previous studies due to the cis-isoprene structure. The CO2/N2 ideal selectivity of 11.6, coupled with a CO2 permeability of 86.9 Barrer, obtained with the 8RD-T25 membrane is comparable to that of a commercial rubber membrane. Furthermore, the use of BRR would decrease the use of non-renewable resources and aggregation of waste, with reduced environmental impact.