Synthesis, characterization of PEA-based polyurethaneurea polyurethaneimide and their pervaporation performances to aromatic/aliphatic hydrocarbon mixtures

摘要

Polyurethaneurea (PU) and polyurethaneimide (PUI) were successfully synthesized from the same soft segment of poly(ethylene adipate)diol (PEA) and different hard segments via a two-step method. The structures and properties of PU and PUI thus obtained were characterized by means of FT-IR, NMR. The membranes of PU and PUI were prepared by solution casting, and the pervaporation (PV) performances were investigated for separating benzene/cyclohexane mixture. Both PU and PUI membranes showed good permeabilities and selectivities towards benzene. PUI membranes showed lower swelling in benzene/cyclohexane mixtures than PU. And PUI membranes had a specific permeation flux of 15.64kg?μm?m -2 ?h -1 and separation factor of 7.68 for 50wt% benzene in the benzene/cyclohexane mixture at 40°C. With the feed temperatures increasing, the flux of the PUI membranes was enhanced, but the separation factor was reduced.