Alkyl chain engineered photo-initiators for the fabrication of biobutanol permselective pervaporation membranes

Despite much progress in the development of photo-initiators (PIs) for many advanced applications, their high migration and weak thermal stability are still challenging. Especially, it easily results in an incomplete curing and sacrificial separation performance in the use of polymeric membranes . PI 2-hydroxy-2-methylpropiophenone (1173) has been most frequently used in photocuring owing to its high reactivity and universal applicability. Herein, we reported a series of alkyl chain engineered PI 1173 with different chain lengths for fabricating polydimethylsiloxane (PDMS) membranes. The dodecyl isocyanate functionalized PI 1173 displayed a lower migration ratio of 1.42% from the PDMS matrix compared with 2.99% for PI 1173. Its degradation temperature was also improved where the weight loss was only 10% as the temperature was raised to 241.1 °C. Importantly, the fabricated PDMS membranes initiated by alkyl chain engineered PIs showed an excellent n -butanol permselective pervaporation (PV) with separation factor of 38–54 and total flux of 818–1396 g m −2  h −1 when feeding 1.5 wt% n -butanol aqueous solution at 60 °C. It provides a general method for fabricating high-quality separation membranes .