Swelling Of Poly-Ether Block Amide Membrane And Its Pervaporation

Poly-ether block amide (PEBA) is one of cheap and getting for easy macromolecule material. The Pervaporation membrane made of it has a nice selectivity for volatility organics. The chemical structure of PEBAx2533 was conformed by infrared spectrum and element analysis. The PEBA homogeneous membrane was prepared by solvent casting. The heat stability of membrane was determined also by DSC-7. The tensile performance of membrane was tested by GB/T10140-9. The results show it has better heat stability and machine intensity. The membrane's swelling behavior in N-butyl acetate, n-butanol, acetic acid and their solution was explored, respectively by swelling tests. The influence of time and temperature as well as liquid concentration on swelling degree was investigated yet. There is the best swelling degree in N-butyl acetate, meanwhile the least in water. The swelling equilibrium was basically achieved after 2 min. The swelling degree increased along with the raise of concentration and temperature.The solubility parameters of membrane were calculated by the method of group contribution and constant of mol gravitation basing on the theory of solubility parameters. The results are closed to them of n-butyl acetate and n-butanol, moreover far away it of water. The solubility of water/organic binary mixtures in the membrane was forecasted with Flory-Huggins and UNIQUAC model respectively. The interaction parameters of the Flory-Huggins have been determined on the theory of solubility parameters. In addition, the interact parameters of solvents and membrane in UNIQUAC model were determined by the data fit of the swelling data. The organics content in the membrane are more and more its content in the liquid mixtures. Its selectivity absorbtion follows the order of n-butyl acetate > n-butanol > acetic acid>water. The calculation results are basic coincident between the Flory-Huggins and UNIQUAC model. This show that the PEBA membrane preferentially absorbtion the organics over water. The results further showed that PEBA is one of good hydrophobic materials.The membrane was used in removal of minim N-butyl acetate and n-butanol from their aqueous solution by pervaporation experiments. The effects of concentration and temperature on the permeation flux and separation factor were studied. The separation impact of N-butyl acetate was better than that of n-butanol. The flux and separation factor increased with N-butyl acetate concentration. The flux increased with temperature, but the separation factor decreased with temperature. The separation factor was 143.9(g·m^-2·h^-1) and 236.9 of N-butyl acetate, respectively, when its concentration to be 0.6 %(w/w).