Polysulfones physical properties

A polysulfone is characterized by the presence of the sulfone group as part of its repeating unit. Polysulfones may be aUphatic or aromatic. AUphatic polysulfones (R and are alkyl groups) were synthesized by radical-induced copolymerization of olefins and sulfur dioxide and characterized many years ago. However, they never demonstrated significant practical utiUty due to their relatively unattractive physical properties, not withstanding the low cost of their raw materials (1,2). The polysulfones discussed in this article are those based on an aromatic backbone stmcture. The term polysulfones is used almost exclusively to denote aromatic polysulfones. 

Table 15.8 Thermal and Physical Properties of Polysulfones (Typical Values)...

Another group of potentially large volume plastics that is under development are the polysulfone resins, made by the copolymerization of olefins such as 1-butene with sulfur dioxide 24). Both these feed stocks could be derived in abundant quantities and at relatively low costs from petroleum sources. The polysulfone resins are moldable thermoplastic polymers having physical properties that vary widely depending on the olefin from which they are prepared. They are considered to have excellent prospects for development to a large volume, low cost commercial plastic and may permit the entrance of plastic products into other fields in which they are now limited by the high cost and inadequate supply of present thermoplastic materials. 

L.M. Robeson, A. Noshay, M. Matzner and C.N. Merian, Physical Property Characteristics of Polysulfone/poly(dimethyl siloxane) Block Copolymers, Angew. Makro-mol. Chem. 29, 47 (1973). 

In the previous section it was suggested that the parent polymer structure considerably influence the physical properties of the derived polysulfonates, imparting to them some of the mechanical and thermal properties of the precursors. This trend is particularly evident in the case of the perfluorinated hydrocarbon polymers. Polymers of this kind, such as e.g., poly(tetrafluoroethylene) (PTFE) are exceptional in their inertness to offensive environment, solvent resistance and high-temperature stability. These considerations led in the sixties to the development of unique sulfonic-acid derivatives of fluorocarbon copolymers by the DuPont Company. While several compositions were disclosed in the patent literature51, the preferred composition, which is the basis for the commercial Nafion ion-exchange membrane, is a copolymer of tetrafluoroethylene with a perfluorinated vinyl ether/sulfonyl fluoride52 ... 

The polymer concentration in the film-forming solution has influence on the physical properties (porosity) of the coatings and the release rate of nutrients from coated granules. Thus for polysulfone-coated NPK fertilizer with coating having 38.5% porosity (prepared from 13.5% polymer solution) 100% of NH4 was released after 5 h test, whereas only 19.0% of NH4 was released after 5 h for the coating with 11% porosity [216]. 

L.M. Robeson, A. Noshay, M. Matz-NER, C. N. Merriam, Physical property characteristics of polysulfone/poly(di-methylsiloxane) block copolymers. An-geiv. Makromol. Chemie 29/30 (1973) 47. 

All of the highly aromatic polymers are resistant, relative to the nonaromatic polymers, to irradiation with either electron beam or y-rays. When irradiated in a vacuum many of these polymers are very stable and can show no change in physical properties even after high beam doses. For example, Kapton and Vespel aromatic polyimides have been shown to have resistance to both y-rays and electron beams up to doses of 100 MGy of irradiation [184]. In the presence of oxygen, the physical properties of the aromatic polymers can be dramatically changed. For example, an aromatic polysulfone showed no change in the flexural strength after irradiation with y-rays to 6 MGy, in vacuo. On the other hand, when the irradiation is carried out in the... 

Those studies were extended to include the addition of an organic montmoril-lonite nanoscale filler to the polysulfone/dicyanate mixture (Mondragon et al. 2006). The primary reason for the introduction of the filler is the significant improvement in properties that can be obtained at low clay contents. The exfoliated configuration for the clay is of particular interest in that regard because it maximizes the interactions, making the entire surface of the clay layers available for interactions with the polymer matrix. This should lead to dramatic changes in both mechanical and physical properties. 

Sulfolane is used as a polymerization solvent for the production of polysulfones, polysiloxanes, polyphenylene ethers, and other polymers. Sulfolane is said to increase the reaction rates, afford easier polymer purification, and improved thermal stability. Sulfolane is a solvent for dissolving a variety of polymers for use in the fiber-spinning process. Cellulose and cellulose ester polymers can be plasticized with sulfolane to give improved flexibility and other physical property improvements [12,13]. Other application areas that have used sulfolane include electronic and electrical, textile-dye uses, curing of polysulfide sealant, and as a catalyst in certain synthetic reactions. 

The conference included presentations covering polysulfone s chemical structure, physical properties and manufacturing processes followed by a tour of the fabrication and laboratory facilities with accompanying demonstrations. 

In order to prepare advanced molecules of poly(arylene ether sulfones) for fuel cell apphcations without sacrificing their excellent physical properties, Noshay and Robeson developed a mild sulfonation procedure for the commercially available bisphenol-A-based poly(ether sulfone) [62,63]. The sulfonation agents that have been used for this polymer modification are chlorosulfonic acid and a sulfur trioxide-triethyl phosphate complex. Recently, Kerres and co-workers [102] reported an alternative sulfonation process of commercial polysulfone based on a series of steps, including metalation-sulfmation-oxidation reactions. 

No books solely focused on polysulfone polymers or blends of polysulfones are available. A good general source of information on many of the general features of polysulfones is the Society of Plastics Engineers (SPE) encyclopedia. There, information about many of the chemical and physical properties can be found. 

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