Chemical Stability and Additive Leach Out in Polyethersulfone Membranes Blended with Dragon Blood Resin: An Investigative Study

Dragon blood resin (DBR) has been reported as an effective bio-based additive for polymeric membrane fabrication. It improves permeability and antifouling properties, but its weak chemical bond makes it susceptible to leaching. This study investigates the chemical stability and leaching behavior of polyethersulfone (PES) membranes modified with DBR in an alkaline solution. The study involved immersing two types of PES-based membranes, one loaded with 3% DBR (M-3) during the fabrication and one without (M-0), in a 0.01-N NaOH solution for 5 days. The results show that M-0 had good resistance to high alkaline solutions, while M-3 was less stable. Pure water permeability and water contact angle increased with immersion time, with an average percentage increase of 90.74 and 19.48%, respectively. The leaching of DBR from the PES membrane could be attributed to its polarity and the breaking of the DBR bonds, causing them to break apart into smaller molecules. The leaching of DBR also leaves a void that increases the pore size. This report provides useful information for the optimal design of a bio-based PES membrane.