Synthesis and characterization of moisture-cured polyurethane membranes and their applications in pervaporation separation of ethyl acetate/water azeotrope at 30°C

Experimental and numerical study of the polyurethane foaming process using high-pressure CO2

A simulation of simultaneous bubble nucleation and growth was performed for polyurethane/CO2 physical foaming process. The single-factor and comprehensive effects of viscoelastic properties, Henry’s constant, CO2 diffusion coefficient and surface tension on the cell morphology were numerically analyzed. The results show that the cell density of PU foam ( N0) increases and its average cell diameter ( Dv) reduces with increased Henry’s constant and slower gas diffusion. Both N0 and Dv reduces with the curing degree ( α). In addition, the effects of α and foaming conditions on the cell structure were experimentally investigated. With an increase of α at foamable range, Dv decreases continuously and N0 increases first and then declines. With increasing saturation pressure and depressurization rate or decreasing temperature, N0 increases and Dv reduces. There is an intrinsic correlation between the simulated and experimental variables, and the results of the simulation and experiment are generally consistent.

Efficient dehydration of the organic solvents through graphene oxide (GO)/ceramic composite membranes

Al₂O₃ tube supported GO composite membranes with submicron thickness and improved mechanical strength were fabricated via a filter-pressing deposition method. High separation performance was achieved in the pervaporation of solvent–water mixtures.

ZSM-5 Filled Polyether Block Amide Membranes for Separating EA from Aqueous Solution by Pervaporation

ZSM-5 filled polyether block amide membranes (PEBA), PEBA/ZSM-5, were prepared and used to recover aroma, ethyl acetate (EA), from aqueous solution by pervaporation (PV). The membranes demonstrated high EA permselectivity, and with the increase of ZSM-5 loading, the separation factor increased initially and then decreased, while the total flux demonstrated the similar variation until the ZSM-5 loading was 10 wt%, at which it reached the lowest value. After that, it began to increase again. On the other hand, the separation factor, and total flux of the PEBA/ZSM-5 membrane containing 10 wt% ZSM-5, PEBA/ZSM-5-10, increased with the increase of feed concentration and temperature. The best PV performance, separation factor and total flux of PEBA/ZSM-5-10 membrane were 185.5 and 199.5 gm−2h−1, respectively, with feed concentration of 5 wt% EA at 50°C.