Given the pressing need for enhancing industrial energy efficiency and process intensification, membrane separation technology possesses significant application potential in industrial waste heat recovery and resource utilization. A thermally stable polybenzimidazole (PBI) with a tribranched topology was functionalized via two strategies: direct sulfonation (ds-tzPBI) and flexible side-chain sulfonation (ls-tzPBI). The effects of sulfonation were systematically investigated, revealing that the resulting ls-tzPBI-1.0 membrane maintained an excellent structural integrity and ion transportability under elevated temperatures (80 °C). This design effectively balances stability and separation efficiency at high temperatures, offering a promising solution for industrial heat recovery.
Li et al. (Mon,) studied this question.