Polysulfone and polyethersulfone

UF membranes are usually prepared by phase inversion. The most widely used polymer for the preparation of UF membranes is polysulfone (PSU) or polyethersulfone (PES). 

Suggestions for hydrophilic membranes have already been proposed that do not suffer from these disadvantages. Several procedures have been proposed to make membrane surfaces more hydrophilic and they will be discussed later. 

Sulfonated polysulfone seems to also play an important role in nanofiltration and reverse osmosis membranes commercialized by Desal. According to Petersen [34] the Desal-5 membrane appears to consist of three layers a microporous polysulfone, a sulfonated overlay and a top ultrathin layer based on polypipera-zineamide. 

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The tensile and flexural properties as well as resistance to cracking in chemical environments can be substantially enhanced by the addition of fibrous reinforcements such as chopped glass fiber. Mechanical properties at room temperature for glass fiber-reinforced polysulfone and polyethersulfone are shown in Table 5. 

Table 5. Properties of Glass Fiber-Reinforced (GR) Polysulfone and Polyethersulfone...

Manea, C. and Mulder, M. 2002. Characterization of polymer blends of poly-ethersulfone/sulfonated polysulfone and polyethersulfone/sulfonated poly-etheretherketone for direct methanol fuel cell applications. Journal of Membrane Science 206 443-453. 

T. Liu, D. Zhang, S. Xu and S. Sourirajan, Solution-spun Hollow Fiber Polysulfone and Polyethersulfone Ultrafiltration Membranes, Sep. Sci. Technol. 27, 161 (1992). 

Membrane polymeric materials for separation applications are made of polyamide, polypropylene, polyvinylidene fluoride, polysulfone, polyethersulfone, cellulose acetate, cellulose diacetate, polystyrene resins cross-linked with divinylbenzene, and others (see Section 2.9) [59-61], The use of polyamide membrane filters is suggested for particle-removing filtration of water, aqueous solutions and solvents, as well as for the sterile filtration of liquids. The polysulfone and polyethersulfone membranes are widely applied in the biotechnological and pharmaceutical industries for the purification of enzymes and peptides. Cellulose acetate membrane filters are hydrophilic, and consequently, are suitable as a filtering membrane for aqueous and alcoholic media. 

Membrane materials for reverse osmosis and ultrafiltration applications range from polysulfone and polyethersulfone, to cellulose acetate and cellulose diacetate [12,18-23]. Commercially available polyamide composite membranes for desalination of seawater, for example, are available from a variety of companies in the United States, Europe, and Japan [24]. The specific choice of membrane material to use depends on the process (e.g., type of liquid to be treated and operating conditions) and economic factors (e.g., cost of replacement membranes and cost of cleaning chemicals). The exact chemical composition and physical morphology of the membranes may vary from manufacturer to manufaemrer. Since the liquids to be treated and... 

The processing of plasma derivatives with ultraliltration is usually conducted in cold rooms. For albumin processing, cassettes and spirals with 10 kDa polysulfone and polyethersulfone membranes have been used to remove the 40% ethanol as quickly as possible and for concentrating the protein to the final concentration of 25%. Typically, 4—5 diafiltration volumes are used to remove ethanol. For high concentration HSA formulations (25%), the protein is first concentrated to 12%, diafiltration conducted under constant volume conditions at that concentration and the protein subsequently concentrated to 25% [21,22]. Typical fluxes for albumin range between 50 and 100 Lmh with operating TMPs ranging between 30 and 50 psi. 

Pol3nners XL-XLIII are commercially available. XL and XLI are referred to as poly-etheretherketone (PEEK) and polyetherketone (PEK), respectively. XLII and XLIII are known as bisphenol A polysulfone and polyethersulfone, respectively. Polymers XLI and XLni can be synthesized not only using the combination of A A and B—B reactants, but also by the self-polymerization of appropriate A—B reactants. 

Case Study Application of Surface-Modified Manbranes Based on Polysulfone and Polyethersulfone in UF/Complexation... 

TABLE 13.6. Glass-transition and secondary-relaxation temperatures of bIsphenol-A polysulfone and polyethersulfone. 

Volume resistivities are listed in Table 5.2. They range from as low as 2 ohm.cm for epoxy resins to as high as 16-18 ohm.cm for high-density polyethylene, polyether ether ketone, polystyrene, polymethylpentene, polyethylene terephthalate, polyarylates, polyphenylene oxide, polyamide imide, polyimides, polyurethane, polytetrafluoro-ethylene, perfluoroalkoxy ethylene, fluorinated ethylene-propylene copolymer, ultra-high-molecular-weight polyethylene, polysulfones, and polyethersulfones. 

The intrinsic viscosity data of the polymer solutions, and the size of the polymer and the polymer aggregate in the casting solutions, were correlated to the pore size and the pore size distribution on the membrane surface prepared from aromatic polyamide, polysulfone, and polyethersulfone polymers [89]-[931. 

BA2 Barth, C., Goncalves, M.C., Pires, A.T.N., Rbder, J., and Wolf, B.A., Asyrrrmetric polysulfone and polyethersulfone membranes effects of thermodynamic corrditiorrs during formation on their performance, J. Membrane Sci., 169, 287, 2000. 

Figure 5.348 Exposure of polysulfone and polyethersulfone to hot steam and/or water at 95 °C Left ultimate tensile strength and toughness after exposure to hot steam...

Table 5.95 shows that polysulfone and polyethersulfone exhibit an increased risk of stress-cracking caused by edible fats and oils. Products made from polyethersulfone are not discolored by food. Table 5.97 [984]. 

Table 5.96 compiles the stress-cracking resistance of polysulfone and polyethersulfone to cleaning agents, disinfectants and other media in medical applications [984]. 

C. Manea, M. Mulder, Characterization of polymer hlends of polyethersulfone/ sulfonated polysulfone and polyethersulfone/sulfonated polyetheretherketone for direct methanol fuel cell apphcations, J. Membr. Sci., 206 (2002) 443-453. 

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