Surface Modification of Polyimide Membrane via Radiation Induced Graft Copolymerization of Methyl Methacrylate: Effects of Monomer Concentration and Radiation Dose

Some membrane processes, such as organic solvent nanofiltration, require membranes with strong chemical resistance to endure harsh chemical environments. Polymeric membranes, while possessing excellent separation properties, are mostly lacking in this area. Due to its inherent chemical resistance, polyimide (PI) stands out as a highly promising material, with the potential to excel in diverse applications where resilience to harsh environments is essential. Therefore, this study attempts to perform a surface modification on PI membrane via radiation induced graft copolymerization (RIGC) of methyl methacrylate (MMA) as the monomer, known to further enhance chemical resistance and organic solvent separation of the membrane. The effects of MMA concentration (0.5, 1.0, 1.5 and 2.0 M) and radiation dose (50, 100, 150 and 200 kGy) on the degree of grafting of poly (methyl methacrylate) (PMMA) and the properties of resultant PI- graft ( g )-PMMA membranes were investigated. The PI- g -PMMA membranes were characterized using atomic force microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analysis and contact angle analysis. The interplay between MMA concentration and radiation dose has not only affected the degree of grafting but also the membrane properties. In conclusion, the findings feature the immense potential of the RIGC technique to modify a highly stable PI membrane to survive in demanding applications within harsh chemical environments.