Synthesis and Characterization of Photocrosslinked Biobased Polyester Membrane

A series of bio-based photocrosslinked polyester membranes, poly(1,8-octanediol-itaconate-citrate-dodecandioate), (POSCI) were synthesized through polycondensation followed by photocrosslinking under UV irradiation in the presence of 2,2-dimethoxy-2-phenylacetophenone (DMPA) as photoinitiator (PI). Upon varied UV exposure time and DMPA content, the corresponding changes in chemical, structural, and mechanical properties of the polymer were studied. The transmission peak of FTIR spectrum centred at 1725 cm-1 indicates the formation of ester structure. Contact angle results suggested all of the synthesized POSCI membranes had hydrophilic properties as their contact angle is less than 90 °.  Sol-gel analysis shows that the swelling ratio of POSCI decreases while the gel fraction increases with increasing in photocrosslinking time. The tensile strength of POSCI, thus, increased correspondingly with longer UV exposure. Excess DMPA, however, proved otherwise.