Polyethersulfone PES

Possible tape materials include polyimide, polyester, polyethersulfone (PES), and polyparabanic acid (PPA) (18). Of these, polyimide is the most widely used material because its high melting point allows it to survive at temperatures up to 365°C. Although polyester is much cheaper than other materials, its use is limited to temperatures less than 160°C. PES and PPA, on the other hand, are half as cosdy as polyimide, and can survive maximum short-term temperatures of 220 and 275°C, respectively. PES has better dimensional stabiUty than polyimide, absorbs less moisture, and does not tear as easily however, it is inflammable and can be attacked by certain common solvents. Table 7 Hsts various plastic tapes and their properties. Common bump materials are gold, copper, and 95% Pb/5% Sn solder (see Tables 6 and 8 for properties see also References 2 and 21). 

The diphenylsulfone group is suppHed to the repeat unit of aU polysulfones by DCDPS the differentiating species between various polysulfones comes from the choice of bisphenol. There are three commercially important polysulfones referred to genericaHy by the common names polysulfone (PSF), polyethersulfone (PES), and polyphenylsulfone (PPSF). The repeat units of these polymers are shown in Table 1. 

The polymerizations of polyethersulfone (PES) and polyphenylsulfone (PPSE) are analogous to that of PSE, except that in the case of these two polymers, solvents which are higher boiling than DMSO are needed due to the higher reaction temperatures required. Diphenyl sulfone, sulfolane, and... 

A number of amorphous thermoplastics are presently employed as matrices in long fiber composites, including polyethersulfone (PES), polysulfone (PSU), and polyetherimide (PEI). AH offer superior resistance to impact loading and higher interlaminar fracture toughnesses than do most epoxies. However, the amorphous nature of such polymers results in a lower solvent resistance, clearly a limitation if composites based on such polymers are to be used in aggressive environments. 

Polysulfone Resins. Commercially important polysulfones are aromatic, ie, in the generalized formula for the repeating unit R and R both contain aromatic rings (see Polymers containing sulfur, polysulfone resins). They all possess ether linkages as weU, so that use of the designations polysulfone, polyarylsulfone (PAS), and polyethersulfone (PES) is somewhat arbitrary. 

The TLCP used was KU 9231 produced by Bayer AG, Germany. The matrix material was an engineering plastic polyethersulfone (PES) manufactured by Jilin University, China. In an earlier article [11] we reported that KU 9231 was incompatible with the PES. 

High-temperature TPs are available to compete with TSs, metals, ceramics, and other nonplastic materials. The heat-resistant TPs include polyetheretherketone (PEEK) and polyethersulfone (PES), polyamideimide, liquid crystal polymer (LCP) and others. 

Table 20-24 compares properties of commonly used polyethersulfone (PES) or regenerated cellulose membranes. Membrane selection is based on experience with vendors, molecular weight rating for high... 

Polyethersulfone (PES) Resistance to temperature, CI2, pH, easy fabrication Hydrophobic... 

To attain this goal, a pervaporation technique has been proposed, using a PVA composite membrane, made by casting of a mixture of PVA aqueous solution and a GA one on a polyethersulfone (PES) porous support, solvent evaporation and thermic curing [72], Excellent dehydration performance has been obtained (separation factor 320 and permeation flux 1.5 kg m 2 h 1, for 90 wt% TFEA in the feed and 80 °C). 

Dual-layer polyethersulfone (PES)/BTDA-TD1/MD1 co-polyimide (P84) hollow fiber membranes with a submicron PES-zeolite beta mixed matrix dense-selective layer for... 

The primary resin of interest is epoxy. Carbon-fiber-epoxy composites represent about 90% of CFRP production. The attractions of epoxy resins are that they polymerize without the generation of condensation products that can cause porosity, they exhibit little volumetric shrinkage during cure which reduces internal stresses, and they are resistant to most chemical environments. Other matrix resins of interest for carbon fibers include the thermosetting phenolics, polyimides, and polybismaleimides, as well as high-temperature thermoplastics such as polyether ether ketone (PEEK), polyethersulfone (PES), and polyphenylene sulfide. 

CMA/20 polycarbonate/polyether (PC) probes have been implanted subcutaneously in rats in our laboratory up to 7-10 days. This membrane chemistry has been discontinued. Failure after 7 days is typical and appears to be due to the foreign body reaction as localized anti-inflammatory administration (dexamethasone) increased the lifetime. (2) CMA/20 polyarylethersulfone (PAES) probes have been implanted subcutaneously for up to 7 days in our laboratory. Failure rates have not been determined. (3) CMA/20 polyethersulfone (PES) probes have been implanted subcutaneously for up to 14 days in our laboratory. Failure rates have not been determined. 

Microfiltration units can be configured as plate and frame flat sheet equipment, hollow fiber bundles, or spiral wound modules. The membranes are typically made of synthetic polymers such as Polyethersulfone (PES), Polyamide, Polypropylene, or cellulosic mats. Alternate materials include ceramics, stainless steel, and carbon. Each of these come with its own set of advantages and disadvantages. For instance, ceramic membranes are often recommended for the filtration of larger particles such as cells because of the wider lumen of the channels. However, it has been shown that spiral wound units can also be used for this purpose, provided appropriate spacers are used. 

Similarly to the case of PES, pyrolysis of bisphenol A polyethersulfone (PES) is very likely radicalic, and the compounds generate by the termination reaction with reaction of two free radicals include dibenzofuran, 4-methyl-dibenzofuran, etc. Also during pyrolysis of PSF it is possible that diphenylsulfone and other sulfur-containing compounds are formed but are not detected in the analysis step. The SO2 group represents 14.48% of the weight of PSF, and only 8.37% molecular SO2 is detected in the pyrogram shown in Figure 12.2.3. 

Li, D.F. Chung, T.S. Wang, R. Liu, Y. Fabrication of fluoropolyimide polyethersulfone (PES) dual layer asymmetric hollow fiber membranes for gas separation. Journal of Membrane Science 2002, 198, 211-223. 

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