Polymers polysulfones

Acrylic ESTER POLYMERS Acrylonitrile POLYMERS Cellulose esters). Engineering plastics (qv) such as acetal resins (qv), polyamides (qv), polycarbonate (qv), polyesters (qv), and poly(phenylene sulfide), and advanced materials such as Hquid crystal polymers, polysulfone, and polyetheretherketone are used in high performance appHcations they are processed at higher temperatures than their commodity counterparts (see Polymers containing sulfur). 

Figure 2.27 Solubilities as a function of critical temperature (Tc) for a typical glassy polymer (polysulfone) and a typical rubbery polymer (silicone rubber) compared with values for the ideal solubility calculated from Equation (2.97)[43]...

Table 4.2 illustrates the various selectivity factors for some typical rubbery polymers, that is, silicone rubber, poly(dimethyl siloxane), and natural rubber, polyiso-prene, and a glassy polymer, polysulfone. Here, we consider the important 02/N2 pair and several pairs involving C02 that will be our focus later. In all the cases, the solubility selectivity is greater than unity and there is not a large difference between rubbery and glassy polymers. For most of these pairs, the diffusion selectivity is greater than unity, but there are some exceptions for C02/02 and C02/N2 that reflect... 

Polycarbonate Polyethylene/polypropylene Cellulosic polymers Polysulfone Nucleporc. Pall Mcmtek. Celgard Koch. MUIIpore Amicon, MHIIpore 20-300 50-250 400600... 

Porous membranes can be made of polymers (polysulfones, polyacrylonitrile, polypropylene, silicones, perfluoropolymers, polyimides, polyamides, etc.), ceramics (alumina, silica, titania, zirconia, zeolites, etc.) or microporous carbons. Dense organic membranes are commonly used for molecular-scale separations involving gas and vapor mixtures, whereas the mean pore sizes of porous membranes is chosen considering the size of the species to be separated. Current membrane processes include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), gas and vapor separation (GS), and pervaporation (PV). Figure 1 indicates the types and sizes of species typically separated by these different separation processes. 

Another engineering polymer, polysulfone, presents excellent resistance to sterilization while it is also well accepted by the human body and thus is adequate for implanted systems. 

Glassy Polymers Polysulfone Polycarbonate Cellulose acetate... 

In this respect the choice of the polymer is not so important, although it directly influences the range solvents and nonsolvents that can be used. In this section the effect of various parameters on membrane morphology will be described. Two widely used polymers, polysulfone (PSf) and cellulose acetate (CA) will be taken as examples. The following factors will be described ... 

As with most linear amorphous polymers, polysulfones are fully thermoplastic materials and readily flow at temperatures >150°C above their respective TgS. The backbone structure is extremely thermally stable during melt processing, remaining imchanged even when subjected to several melt fabrication cycles. 

The presence of reinforcanent in polymer (nano)composites (Thomas et al. 2011 Wen 2007) generally increases the value of E modulus due to restrictions of vibrations and short-range rotational motions (Bindu and Thomas 2013 Dufresne 2000 Liu et al. 2005 Musto 2006). Exceptions to this behavior exist, and one of them was reported on the EeS2/polyimide composite (Sava 2009). Incorporation of low quantities of pyrite microparticles restrains the possible physical interactions among polyimide chains, decreasing the rigidity of the composite relative to the pristine polyimide. Another situation was mentioned for an all-polymer composite obtained from a pair of incompatible polymers polysulfone (PSF) (the matrix polymer) and cross linked polydimethylsiloxane (PDMS) submicron particles (the disperse phase) (Racles et al. 2013). All-polymer composites contain polymer nanoparticles as the disperse phase in a polymer matrix and, from the point of view of properties, these are situated between polymer blends and polymer composites. The PDMS particles act like a plasticizer for the PSF matrix (E p p = 2 GPa, E psp/pp,Ms = 0.7 GPa). 

Thermal, thermal-oxidative 674 Polystyrene, see Styrene polymers Polysulfone. see High-temperature polymers Polytetrafluoroethylene. see Fluoropolymers Polytrifluorochloroethylene. see Fluoropolymers Polyurethane... 

Fu et al. [11] reported the acid-base blend membranes based on 2-amino-benzimidazole (basic polymer) and sulfonated poly(ether ether ketone) (SPEEK) (acidic polymer) for direct methanol fuel cells. A novel polymer, polysulfone-2-amide-benzimidazole (PSf-ABIm), using carboxylated polysulfone and 2-amino-benzimidazole was synthesized for this purpose. The blend membrane of SPEEK/PSf-ABIm showed high performance a s represented by Figure 1.12. The blend membrane with 3 wt% PSf-ABIm was evaluated continuously for 120 h and little or no decline in performance was found after 120 h. On the other hand, the Nafion 112 membrane standard was observed to have a decline in performance due to a much higher amount of methanol crossover. 

For many years, several polymers have been investigated intensively for their potential as membrane materials in proton exchange membrane fuel cell. Research groups have sought to improve the existing material and to find alternative polymer that possess similar performance as the standard Nation membrane. Among the other polymers, polysulfone was considered to be the... 

Trogadas and Ramani summarized the modification of PEM membranes, including Nafion modified by zirconium phosphates, heteropolyacids, hydrogen sulfates, metal oxides, and silica. Membranes with sulfonated non-fluorinated backbones were also described. The base polymers polysulfone, poly(ether sulfone), poly(ether ether ketone), polybenzimidazole, and polyimide. Another interesting category is acid-base polymer blend membranes. This review also paid special attention to electrode designs based on catalyst particles bound by a hydrophobic poly-tetrafluoroethylene (PTFE) structure or hydrophilic Nafion, vacuum deposition, and electrodeposition method. Issues related to the MEA were presented. In then-study on composite membranes, the effects of particle sizes, cation sizes, number of protons, etc., of HPA were correlated with the fuel cell performance. To promote stability of the PTA within the membrane matrix, the investigators have employed PTA supported on metal oxides such as silicon dioxide as additives to Nafion. 

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