Polysulfones Density

In these beds, pore size is determined by the number of nearest neighbors (coordination number) n, the sphere radius r, and the type of packing geometry. Two radii characterize the pore size one for the "throat" and one for the "cavity" of the pore (18). Isotherms have been calculated similar to those of Reference (2.), for polysulfone (density 1.370 g/cm ) spheres for values of n 4,6,8,10 (tetrahedral, primitive cubical, body-centered cubical, body-centered tetragonal geometries, respectively). Nitrogen vapor at -195.6°C was assumed and the adsorbed layer thickness was calculated with Halsey s equation (15) as in the cylindrical pore model. Calculated isotherms are plotted in Figure 5. 

Fig. 6. Melt viscosity dependence on shear rate for various polymers A, low density polyethylene at 210°C B, polystyrene at 200°C C, UDEL P-1700 polysulfone at 360°C D, LEXAN 104 polycarbonate at 315°C and E, RADEL A-300 polyethersulfone at 380°C.

After cooling of the aqueous mixture to 5-10°C an upper viscous phase is separated, which contains 45-47% alkanesulfonates and 1.0-1.3% sodium chloride, while the lower phase is a 7-8% brine with a small quantity of alkane-monosulfonates but 1.5-2.0 wt % di- and polysulfonates. The hydrotropically dissolved alkanes (neutral oil) are found entirely in the upper phase. Because of the small density differences, the separation of the two phases needs 15-20 h. The lower phase can be separated by membrane technology [13]. 

Direct fluorination of polymer or polymer membrane surfaces creates a thin layer of partially fluorinated material on the polymer surface. This procedure dramatically changes the permeation rate of gas molecules through polymers. Several publications in collaboration with Professor D. R. Paul62-66 have investigated the gas permeabilities of surface fluorination of low-density polyethylene, polysulfone, poly(4-methyl-1 -pentene), and poly(phenylene oxide) membranes. 

PS PSF PSU PTFE PU PUR PVA PVAL PVB PVC PVCA PVDA PVDC PVDF PVF PVOH SAN SB SBC SBR SMA SMC TA TDI TEFE TPA UF ULDPE UP UR VLDPE ZNC Polystyrene Polysulfone (also PSU) Polysulfone (also PSF) Polytetrafluoroethylene Polyurethane Polyurethane Poly(vinyl acetate) Poly(vinyl alcohol) poly(vinyl butyrate) Poly(vinyl chloride) Poly(vinyl chloride-acetate) Poly(vinylidene acetate) Poly(vinylidene chloride) Poly(vinylidene fluoride) Poly(vinyl fluoride) Poly(vinyl alcohol) Styrene-acrylonitrile copolymer Styrene-butadiene copolymer Styrene block copolymer Styrene butadiene rubber Styrene-maleic anhydride (also SMC) Styrene-maleic anhydride (also SMA) Terephthalic acid (also TPA) Toluene diisocyanate Ethylene-tetrafluoroethylene copolymer Terephthalic acid (also TA) Urea formaldehyde Ultralow-density polyethylene Unsaturated polyester resin Urethane Very low-density polyethylene Ziegler-Natta catalyst... 

To obtain membranes with different ion-exchange capacity the sulfonated polyetheretherketone or polysulfone can be mixed with unsulfonated polymer in a solvent such as N-methylpyrrolidone. By changing the ratio of the sulfonated to unsulfonated polymer the fixed-charge density can easily be adjusted to a desired value. 

PB PBI PBMA PBO PBT(H) PBTP PC PCHMA PCTFE PDAP PDMS PE PEHD PELD PEMD PEC PEEK PEG PEI PEK PEN PEO PES PET PF PI PIB PMA PMMA PMI PMP POB POM PP PPE PPP PPPE PPQ PPS PPSU PS PSU PTFE PTMT PU PUR Poly(n.butylene) Poly(benzimidazole) Poly(n.butyl methacrylate) Poly(benzoxazole) Poly(benzthiazole) Poly(butylene glycol terephthalate) Polycarbonate Poly(cyclohexyl methacrylate) Poly(chloro-trifluoro ethylene) Poly(diallyl phthalate) Poly(dimethyl siloxane) Polyethylene High density polyethylene Low density polyethylene Medium density polyethylene Chlorinated polyethylene Poly-ether-ether ketone poly(ethylene glycol) Poly-ether-imide Poly-ether ketone Poly(ethylene-2,6-naphthalene dicarboxylate) Poly(ethylene oxide) Poly-ether sulfone Poly(ethylene terephthalate) Phenol formaldehyde resin Polyimide Polyisobutylene Poly(methyl acrylate) Poly(methyl methacrylate) Poly(methacryl imide) Poly(methylpentene) Poly(hydroxy-benzoate) Polyoxymethylene = polyacetal = polyformaldehyde Polypropylene Poly (2,6-dimethyl-l,4-phenylene ether) = Poly(phenylene oxide) Polyp araphenylene Poly(2,6-diphenyl-l,4-phenylene ether) Poly(phenyl quinoxaline) Polyphenylene sulfide, polysulfide Polyphenylene sulfone Polystyrene Polysulfone Poly(tetrafluoroethylene) Poly(tetramethylene terephthalate) Polyurethane Polyurethane rubber... 

Second 1950 1965 High-density polyethylene, isotactic polypropylene, polycarbonate, polysulfones, linear polyesters, synthetic rubbers Improved mechanical strength... 

Most applications of GP use dense membranes of cellulose acetates and polysulfones. For high-temperature applications where polymers cannot be used, membranes of glass, carbon, and inorganic oxides are available, but they are limited in their selectivity. Almost all large-scale applications of GP use spiral-wound or hollow-fiber modules, because of their high packing density. 

But of prime importance with regard to the final separation process is the nature of the membrane-forming polymer its hydrophihdty, charge density, polymer structure and molecular weight Typical polymers used in this phase-separation process are cellulose esters (most commonly CA), polyamides, poly(amide-hydra-zides), polyimides, (sulfonated) polysulfones, poly(phenylene oxide) and (sulfona-ted) poly(phthalazine ether sulfone ketone). 

Low-density polyethylene and polypropylene in the form of flat-sheet and hollow-fiber membranes are used in plasmapheresis and as oxygenators in the heart-lung machine. Other materials commonly used in plasmapheresis are cellulose acetate, polycarbonate, and polysulfone [129]. 

ZHA Zhang, W. and Kiran, E., Phase behavior and density of polysulfone in binary fluid mixtures of tetrahydrofuran and carbon dioxide under high pressure miscibility windows, J. Appl. Polym. Sci., 86, 2357, 2002. 

Features of the new, inherent, flame-resistant active polymers such as PSU (polysulfone), PES (polyether sulfone), and PAEK (polyarylether ketone) include high levels of temperature resistance and very low smoke gas densities. 

Although there are a number of materials with the desired pore structure, for instance silicone rubbers, hydrocarbon rubbers, polyesters, polycarbonates and others, their use for industrial applications is limited to polysulfones and cellulose acetates. While the latt have been used with good success for dehydration, technical gas separation relies exclusively on polysulfones which can be used up to approximately 70 °C (their melting point is around 200 °C) and at pressures between IS and 140 bar. The lowest pressure differential between the feed gas side and the permeate gas side is 3 1 and this differential pressure determines the wall thickness of the membranes. Figure 2.8 shows the design of a membrane element developed by Monsanto Company, USA and marketed by the name of Prism separator. Each of these elements or modules contains thousands of hollow fibres packed to a density of approximately 1(X) per cm. ... 

---