Astrel

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also introduced a material intermediate between III and V known as Polyethersulphone 720P (IV) but which has now been withdrawn.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. 

There are several types of polyaryl sulfones available commercially. The classic polysulfone (Udal) was produced by the nucleophilic displacement of the chlorine substituents on bis(p-chlorophenyl) sulfone by the sodium salt of blsphenol A.Another polysulfone (Astrel) is produced by the Friedel-Crafts condensation of biphenyl with oxy-bis(benzene sulfonyl chloride). Another polysulfone (Vitrex), is produced by the alkaline condensation of bis(chlorophenyl) sulfone. (28.)Blends of polysulfones with ABS (Arylon, Mlndel) and SAN (Ucardel) are available. 

Polyarylsulfones are a class of high-use temperature thermoplastics that characteristically exhibit excellent thermal-oxidative resistance, good solvent resistance, hydrolytic stability, and creep resistance (10). In 1965, Union Carbide announced a thermoplastic polysulfone based on dichlorodiphenylsulfone and bisphenol A (11). This polysulfone became commercially available in 1966 and was designated as Udel polysulfone. Since 1966, Imperial Chemical Industry (ICI), Minnesota Mining and Manufacturing (3-M), and Union Carbide have commercialized polyarylsulfones that contain only aromatic moieties in the polymer structure. These materials have been designated Vlctrex polyethersulfone (ICI), Astrel 360 (3-M), and Radel polyphenylsulfone (Union Carbide). 

Property Udel (Union Carbide) Victrex (ICI) Astrel (3M)... 

Astrel" 360 (3M Coi-p) r and % 550°F injection moulds in specially modified machines. 

Besides the aromatic polysulfone on the basis of bisphenylpropane, the other aromatic polysulfones are produced industrially. In particular, the industrial manufacture of polysulfones has been carried out by company Plastik 3 M (USA) since 1967 (the polymers are produced by reaction of electrophylic replacements at presence of catalyst). The polysulfone labeled Astrel-360 contains links of following constitution ... 

The company ICI (Great Britain) produced polysulfones identical to Astrel-360 in its chemical structure. However, the polymer 720 P of that firm contains greater number of second-type links. Due to this, the glassing temperature of the polymer is 250 °C and its reprocessing can be done on standard equipment [153]. 

Pure aromatic structure of given polymers brings them high thermooxidation stability and deformation resistance. Mechanical properties of polysulfone allow one to classify them as technical thermoplasts having high durability, rigidity and impact stability. The polymer Astrel 360 is in the same row with carbon steel, polycarbonate and nylon on its durability. 

The polysulfone Astrel-600 can be reprocesses at harder conditions. Depending on the size and shape of the article, the temperature of pressed material should lie within the ranger of 315-410 °C while pressure should be about 350 MPa [158]. The given polysulfone can be reprocessed by any present method. Articles from it can be mechanically treated and welded. Thanks to its properties, polysulfone finds broad use in electronique, electrotechnique and avia-industry [159, 160]. 

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