Radel

These solvents include tetrahydrofuran (THF), 1,4-dioxane, chloroform, dichioromethane, and chloroben2ene. The relatively broad solubiHty characteristics of PSF have been key in the development of solution-based hoUow-fiber spinning processes in the manufacture of polysulfone asymmetric membranes (see Hollow-fibermembranes). The solvent Hst for PES and PPSF is short because of the propensity of these polymers to undergo solvent-induced crysta11i2ation in many solvents. When the PES stmcture contains a small proportion of a second bisphenol comonomer, as in the case of RADEL A (Amoco Corp.) polyethersulfone, solution stabiHtyis much improved over that of PES homopolymer. 

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.

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. 

As of November 1, 1995, the price range of UDEL polysulfone resias ia large quantities was 9.10— 12.03/kg depending on grade and color. RADEL A polyethersulfone grades sold for 10.46— 13.26/kg and the prices of RADEL R polyphenylsulfone resias were ia the range 15.75— 25.95/kg. MINDEL resias based oa polysulfoae had Hst prices betweea 6.72— 7.42/kg. 

Union Carbide introduced the first commercial polyarylsulfone resin, Udel, in 1966 and later introduced Radel polyarylsulfone. The business and patents rights were acquired by Amoco Corp. in 1986. Other polysulfone products have been marketed by BASF and ICl (Victrex PES) the latter aimounced in 1991 it was withdrawing from the business. 

The resins are made by batch processes employing Friedel-Crafts reactions or nucleophilic aromatic substitution. Udel resin and Radel R resin are produced by the nucleophilic displacement of chloride on 4,4 -dichlorodiphenyl sulfone by the potassium salts of bisphenol A and 4,4 -biphenol, respectively (97) ... 

Radel A 400 polyarylsulfone lesin is made from a piopiietaiy blend of bisplienols (believed to include hydioquinone) and dichloiodiphenyl sulfone. Victiex lesin is made by other displacement reactions. 

Amoco Performance Products (Atlanta, Ga.), is the sole supplier of polysulfone, Udel, polyarylsulfone, Radel A, and polyphenylsulfone, Radel R. ICI Advanced Materials (Exton, Pa.), is the sole domestic supplier of the polyethersulfone, Victrex PES, but announced ia 1991 it was withdrawing from the business. 

HCIO4). Refluxed with benzene (6mL/g) in a flask fitted with a Dean and Stark trap until all the water was removed azeotropically (ca 4h). The soln was cooled and diluted with dry pentane (4mL/g of AgC104). The ppted AgC104 was filtered off and dried in a desiccator over P2O5 at 1mm for 24h [Radell, Connolly and Raymond J Am Chem Soc 83 3958 1961]. It has also been recrystallised from perchloric acid. [Caution due to EXPLOSIVE nature in the presence of organic matter.]... 

The first commercial polymer Table 21.3, II) was offered in 1965 by Union Carbide as Bakelite Polysulfone, now renamed Udel. In 1967 Minnesota Mining and Manufacturing introduced Astrel 360 Table 21.3, V), which they referred to as a polyarylsulfone. In 1972 ICI brought a third material onto the market which they called a polyethersulphone (III) and which they then marketed as Victrex. They also introduced a material intermediate between III and V known as Polyethersulphone 720P (IV) but which has now been withdrawn. In the late 1970s Union Carbide introduced Radel (VI), which has a higher level of toughness. Around 1986 Union Carbide sold their interest in polysulphones to Amoco. In addition the Astrel materials were produced by Carborundum under licence from ICI. 

Iwata N, Cowley DS, Radel M, et al Relationship between a GABA alpha g Pro385Ser substitution and benzodiazepine sensitivity. Am] Psychiatry 156 1447—1449,1999 Jacobson AF, Dominguez RA, Goldstein B, et al Comparison of buspirone and diazepam in generalized anxiety disorder. Pharmacotherapy 5 290—296, 1985 Jaffe JH, Ciraulo DA, Nies A, et al Abuse potential of halazepam and diazepam in patients recently treated for acute alcohol withdrawal. Clin Pharmacol Ther 34 623-630, 1983... 

Radel M, Goldman D Pharmacogenetics of alcohol response and alcoholism the interplay of genes and environmental factors in thresholds for alcoholism. Drug Metah Dispos 29 489 94, 2001... 

Airex, Mindel, Radel, Stabar, Udel, Ultrason. .. 

Union Carbide, in 1976, made available a second generation polysulfone under the trade name Radel. Radel was formed from the reaction of a bisphenol and bis(p-chlorophenyl) sulfone (structure 4.76). This polysulfone exhibits greater chemical and solvent resistance, greater Tg of 220°C, greater oxidative stability, and good toughness in comparison to Udel. 

Radel Poly(ether sulfone) Amoco Polymers... 

Iwata N, Cowley DS, Radel M, Roy-Byrne PP, Goldman D (1999) Relationship between a GABAA alpha 6 Pro385Ser substitution and benzodiazepine sensitivity. Am J Psychiatry 156 1447-1449... 

Semidei, Radel, L. and Nolan, C. (2001) Substance abuse and child welfare clear linkages and promising responses. Child Welfare League of America 80, 2, 109-128. 

Films of the polyisoimides were cast from DMAC at 55 °C under reduced pressure (0.1 mm). A study of the isomerization reaction was conducted by FTIR and showed that the isomerization began at approximately 100 °C and was complete after 3 h at 250 °C. In all cases the thermally treated films were insoluble in all solvents tested. Composite films were produced with XVII and three commercial matrix systems a polyarylsulfone (Radel), a polysulfone (Udel), and an acetylene terminated isoimide thermosetting resin (IP-600). Films of the matrix and XVII were cast from DMAC. Slightly cloudy films, indicating some phase separation, resulted with both the Radel and Udel systems. Composite films cast with IP-600, however, were completely clear and showed no signs of phase separation. The structural similarity of the IP-600 resin and XVII may account for the greater homogeneity of the system. Property assessment of these films before and after thermal treatment is currently underway. 

Submitted hy P. A. Wender, P. A. Holt, and S. McN. Sieburth. Checked by Peggy A, Radel and Clayton H. Heathcock. 

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