Heterogeneous Sulfonation Of Copoly(Phthalazinone Ether Sulfone) And Preparation Of Composite Membrane

Taking DHPZ, HQ, DCS as'monomers, copoly (phthalazinone ether sulfone) (PPHESs) had been successfully synthesized via step polymerization method and PPHESs with different structure had been characterized via'H-NMR. The introduction of ether linkage had well improved the toughness of copolymer. However, their hydrophilicity was not so good. Sulfonation is one of the effective methods to improve hydropobic character of copolymer. Sulfuric acid with different concentration as sulfonating agent, chloroform as solvent, heterogeneous sulfonation method was used to prepare SPPHESs with various sulfonation degrees (SD). The effects of sulfonation process (the concentration of sulfuric acid, reaction temperature and time and concentration ratio of PPHES/sulfuric acid) on SD of SPPHES were investigated respectively. The SPPHES was characterized by FT-IR,'H-NMR spectra and TGA. The water uptake, swelling ratio and solubility of SPPHES were also studied. The experimental results showed that SD increased as the increasing of the concentration of sulfuric acid, reaction temperature; in a certain time, SD increased as the time going and kept stable after two hours reaction. SD decreased as the increasing of concentration ratio of PPHES/sulfuric acid. FT-IR and'H NMR spectra confirmed that sulfuric acid groups were introduced into the polymer chain successfully. SPPHES was soluble in NMP, DMAc, DMSO and DMF etc. The water uptake and swelling ratio of SPPHES increased as the increasing of SD and test temperature. TGA indicated that SPPHES had good thermo-stability.SPPHES composite nanofiltration membrane was prepared with PPESK UF membrane as substrate and SPPHES as the coating layer. The effects of coating solution components and preparation technics on the properties of NF membranes were investigated in details. According to the experiment results, when SD of SPPHES was 0.85, components of coating solution were:the polymer concentration was 2.0wt%, mixed EGME and ethanol (4:1) as the solvent, the addition amount of glycerin as cross-linking reagent was about 25wt.%, the addition amount f DMAc as aprotic solvent was 5wt%, the quantity of LiCl as inorganic additive was 1wt%and heat-treating at 90℃for thirty minutes or so, the membrane showed excellent properties. The water flux of this excellent composite membrane was 107.4L/(m2·h), and the rejection rate for 1000ppm Na2SO4 solute could be 94.5%when the operation pressure was 1.OMPa at room temperature. The pressure resistance and heat resistance experiments showed that the SPPHES/PPESK composite membrane had excellent pressure and heat resisting property. The anti-acid, anti-alkali and anti-chlorine experiments showed that the PPHES/PPESK composite membrane had well acid, alkali and chlorine resisting property.