Blends of polyethersulfone

However, the opposite effects are also known, as for example, in blends of polyethersulfone (PES) with polyaramid (PARA) prepared by polycondensation of bis (4-aminophenyl)ether with isopthaloyl chloride [Nakata et al, 1990]. The PARA had been thought to be an amorphous polymer, whereas it did crystallize in the blend. The results suggest that the crystallization of PARA was induced by the presence of PES, i.e., this is an example of the blend-induced crystallization. The aramid seems to be a dormant crystalline polymer. In other words, the crystallizability is latent but crystallization in neat PARA was not possible even when annealing - it did take place in the presence of PES. This may be due to an increase of chain mobility by decreasing the glass transition temperature (T ) on blending PARA with PES that has lower T. ... 

Engberg et al. [67,68] prepared blends based on Vectra A950 and several flexible chain polymers. The order parameter of the PLC component in injection molded blends of polyethersulfone (PES) and Vectra, referring to the whole cross-section (thickness of specimen 1.5 mm), was according to X-ray scattering data close to 0.4 and also independent of the composition of the blend [67]. The lower chain orientation found in these samples reflects the fact that shear flow is less effective in orienting PLCs than extensional flow. 

GOM Gomez, C.M., Figuemelo, J.E., and Campos, A., Evaluation of thermodynamic parameters for blends of polyethersulfone and poly(methyl methaciylate) or polystyrene in dimethylformamide, Ro/ywzer, 39, 4023, 1998. 

C. Manea and M. Mulder, Characterization of polymer blends of polyethersulfone/sulfonated polysulfone and polyethersulfone/sulfonated polyetheretherketone for direct methanol fuel cell applications, J. Membr. Sci. 206,443 (2(X)2). 

Abstract The miscibility behavior in blends of polyethersulfone (Victrex PES) with the polyimide PI 2080, (the condensation product of 3,3, 4,4 -benzophenone tetracarboxylic dianhydride [BDTA] and a 4 1 mixture of 2,4-toluene diisocyanate and 4,4 -diphenylmethane diisocyanate) or with the polyimide XU 218 (the condensation product of BDTA and 5(6)-amino-l-(4 -aminophenyl)-l,3,3 -trimethylindane) was investigated using differential scanning calorimetry, dynamic mechanical analysis and thcmiogravimetric analysis. The effects of solvents (dimethylacetamide, tetramethylene sulfone, dimethyl sulfoxide and l-methyl-2-pyrrolidone) on miscibility were studied and one solvent, tetramethylene sulfone was found to have a plasticizing effect. In the absence of solvent, the equilibrium phase boundary for these blends was in the experimentally inaccessable region below the Tg-composition line. The phase boundary at zero solvent concentration was obtained by extrapolation using data collected in the presence of the plasticizer. 

It is known that, in a polymer blend, thermodynamic incompatibility between polymers usually causes demixing of polymers. If the polymer is equilibrated in air, the polymer with the lowest surface energy (hydrophobic polymer) will concentrate at the air interface and reduce the system s interfacial tension as a consequence. The preferential adsorption of a polymer of lower surface tension at the surface was confirmed by a number of researchers for a miscible blend of two different polymers. Based on this concept, surface modifying macromolecules (SMMs) as surface-active additives were synthesized and blended into polymer solutions of polyethersulfone (PES). Depending on the hydro-phobic or hydrophilic nature of the SMM, the membrane surface becomes either more hydrophobic or more hydrophilic than the base polymeric material. ... 

The specialty resins are expensive, produced in relatively small volumes either for a specific application or looking for a market niche. Their Tg > 200°C and modulus > 3 GPa. In 1991 the total world consumption of polysulfones (PSE) and polyethersulfones (PES) was 8.5 kton. Blends of the following polymers are known polyfluorocarbons, polysiloxanes, sulfur-containing polymers (PPS, PPSS, PES, and PSF), polyetherk-etones (PEK, PEEK, PEKK), polyimides (PI, PEI, and PAI), PAr, COPO, polyphosphazene (PHZ) and LCP. 

Thermoplastics are sometimes added to epoxy resins. Thermoplastic-modified epoxy resins [43,44] based on tri- and difunctional epoxy resins cured with DDS and blended with polyethersulfone form the basis for the matrix material in a composite used for the Boeing 777 aircraft. The incorporation of the thermoplastic helps the processing characteristics and also improves the mechanical properties, notably the toughness. The thermoplastic is able to phase separate from the epoxy phase and acts as a reinforcement for the epoxy matrix, enhancing its high temperature properties. The maximum use temperatures of all these resins will typically be 30 to 50 degrees lower than the cited Eg, assuming the same cure schedule. 

Engberg and coworkers [14,98] investigated the blends of thermotropic PLCs with fully amorphous polymers polyethersulfone (PES), polycarbonate (PC) and aromatic poly (ester carbonate) (APEC) [98] and semicrystalline polymers like polybutylene terephthalate (PBT) [14]. aL was calculated according to the Takayanaga model [101] as follows ... 

Weber and Giintherberg (1999) have prepared compatibilized blends of PA and polyethersulfone in the presence of S-MA-(N-phenylmaleimide) terpolymer. In the examples, the PA was derived either from hexamethylenediamine-isophthalic acid or from hexamethylenediamine-caprolactam-terephthalic acid. Blends comprising PA, an amine-terminated polyethersulfone, and S-MA-(N-phenylmaleimide) terpolymer prepared in a Haake mixer were characterized using mechanical properties testing, selective solvent extraction, DSC, and Vicat B test. Blends optionally contained phenoxy resin. 

Kanomata et al. (2011) prepared compatibilized blends of either PBT or PET and polyethersulfone using PES having hydroxyphenyl end-groups. Blends prepared in a Brabender mixer were characterized using TEM and torque rheometry in comparison with control blends. 

The properties of the main polysulfones are generally similar, although polyethersulfones have better creep resistance at high temperatures, higher heat-distortion temperature, but more water absorption and higher density than the Udel type materials. Glass fiber-filled grades of polysulfone are available as are blends of polysulfone with ABS. 

L. Wang, B.L. Yi, H.M. Zhang, D.M. Xing, Characteristics of polyethersulfone/sulfo-nated polyimide blend membrane for proton exchange membrane fuel cell, J. Phys. Chem. B 112 (14) (2008) 4270 275. 

Li L, Cheng C, Xiang T, Tang M, Zhao W, Sun S, et al. Modification of polyethersulfone hemodialysis membrane by blending citric acid grafted polyurethane and its anticoagulant activity. J Membr Sci 2012 405-406 261-74. 

Schult, K.A. and Paul, D.R. (1997) Water sorption and transport in blends of polyethyloxazoline and polyethersulfone. 

The excellent resistance of polyethersulfone to engine and transmission oils are also found in PES/PA blends. Figure 5.347 [925]. 

Deimede, V., Kandilioti, G., Kallitsis, J.K., Gregoriou, V.G. (2005) Blends of sulfonated polysulfone and poly(ethylene oxide)-grq/ieii-polyethersulfone as proton exchange membranes for fuel cell applications. Macromolecular Symposia, 230, 33-38. 

Y. Mansourpanah, S.S. Madaeni, A. Rahimpour, Z. KheiroUahi, and M. Adeli, Changing the performance and morphology of polyethersulfone/polyimide blend nanofiltration membranes using trimethylamine. Desalination 256 (2010) 101-107. 

Proprietary blend formulations based on polysulfone, polyethersulfone, and polyphenylsulfone are sold commercially by Amoco Corporation to meet various end use requirements. The blends based on polysulfone are sold under the MINDEL trademark. A glass fiber-reinforced blend based on PES is offered under the trade name RADEL AG-360. This offers most of the performance characteristics of 30% glass fiber-reinforced polyethersulfone but at a lower cost. Two blend product lines are offered based on PPSF. These are designated as the RADEL R-4000 and R-7000 series of products. The former is a lower cost alternative to RADEL R PPSF homopolymer offering most of the performance attributes unique to PPSF. The R-7000 series of resins have been formulated for use in aircraft interiors for civil air transport. They exhibit a very high degree of resistance to flammabihty and smoke release. 

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