Polysulfones and Polysulfides

Polysulfone, PSU Poly(ether sulfone), PES. Applications injection-molded parts, coatings, electronic articles, printed circuits, houseware, medical devices, membranes, lenses, optical devices. 

Polyiphenylene sulfide), PPS. Applications injection-molded parts, sintered parts, foils, fibers, housings, sockets, foams. 

Vicat softening temperature rv50/50 (°C) Thermal conductivity A. (W/(mK)) 

Notched impact strength (Charpy) (kJ/m ) Sound velocity i s (m/s) (longitudinal) 

Melt viscosity-molar-mass relation Viscosity-molar-mass relation 

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Industrially important sulfur-containing polymers are polysulfones and polysulfides. The materials differ considerably in properties and in use. 

Various types of condensation polymers such as aromatic polysulfonates and polysulfides, aromatic polyethers, aliphatic and aromatic polysulfides, and carbon-carbon chain polymers of high molecular weights by the phase-transfer catalyzed polycondensation fi-om combinations of aromatic disulfonyl chlorides, phosphonic dichlorides, activated aromatic dichlorides, and aliphatic dihalides, withbisphenol, aliphatic and aromatic dithiols, and active ethylene compounds. The two-phase polycondensation was generally carried out in a water-immiscible organic solvent-aqueous alkaline solution system at room temperature. The method of polycondensation offers a highly versatile and convenient synthetic method for a variety of condensation polymers. 

Resins for advanced composites can be classified according to their chemistry typical resins are polyaryletherketones, polysulfides, polysulfones, and a very broad class of polyimides containing one or more additional functional groups (Table 2) (see also Engineering plastics). 

A number of plastics are condensation polymers and include polyesters and nylons that are not as highly oriented as the same materials but in fiber form. Other plastics have been developed that have outstanding heat stability, strength, and other properties that allow their wide use. These plastics include polycarbonates, polyimides, polybenzimidazoles, polysulfides, polyethers, polysulfones, and polyketones. 

The presence of sulfur in polysulfides, polysulfones, and in sulfur-vulcanized rubber can be demonstrated by the following somewhat uncertain test. The sample is heated in dry air (pyrolysis) and the gases formed during this process are bubbled through a dilute barium chloride solution. The presence of sulfur is indicated by a white precipitate of barium sulfate. 

Mihtskova, A. M., Artemov, S. V. (1990). Aromatic polysulfones polyester (ester) ketones, polyphenylenoxides and polysulfides of NllTEHIM Review. Moscow, 1 3 [in Russian]. 

Polyethers, polysulfones, polyterephthalamides and polysulfide polymers, and several other high temperature polymers are also part of this group, but they are still produced in low volumes. 

High-temperature thermoplastics such as polyarylate, polyketone, polysulfide, polysulfone, and thermoplastic polyimide have inherently good resistance to thermal-oxidative conditions however, stabilization against UV-light is often required. The principles described earlier for other thermoplastics also apply to the stabilization of these plastics. 

Although inhibitors are deliberately added to the silicone formulation to control cure rate, unwanted cure inhibition can be caused by other species that react to form strong complexes with the platinum catalyst. Most notable of these undesired inhibitors include organotin and other organometallic compounds, sulfur, polysulfides, polysulfones or other sulfur-containing materials, amines, urethanes or amine-containing materials, unsaturated hydrocarbons in plasticizers, and some solder flux residues. 

Few argue that we have much to learn about the Thiokols and other polysulfide elastomers, the polysulfones, which have such interesting properties as the engineering plastics, and the episulfides. The chemistry of pyrites, carbon disulfide, sulfur dioxide, dimethyl sulfoxide, and many other compounds merit separate reviews. 

Recent efforts in the synthesis of sulfonated aromatic polymers are directed to the polymerization of sulfonated monomers (such as (b), (d), (g), (j), (k), and (1) shown in Scheme 3) [14,15,53,54,96-102] or coupling reactions of sulfonated compoimds with fimctional groups attached to a polymer backbone [ 103,104]. In post-sulfonation, attachment of the sulfonic acid group is restricted to the activated position ortho to the aromatic ether bond, as indicated in Scheme 4a, while in direct polymerization of sulfonated monomers, the sulfonic acid groups are attached to the deactivated site on the ring (Scheme 4b). An enhancement of stabUity toward desulfonation and a modestly higher acidity are expected for the structure shown in Scheme 4b. Recently, polymerization of sulfonated monomers was also used to obtain sulfonated polysulfone (m) via oxidation of a sulfonated polysulfide-polysulfone copolymer [105]. 

The pol3miers given in this chapter are divided into polyolefines, vinyl polymers, fiuoropolymers, polyacrylics, polyacetals, polyamides, polyesters, polysulfones, polysulfides, polyimides, polyether ketones, cellulose, polyurethanes, and thermosets. The structural units of the polymers are as follows ... 

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. 

It is clear from these results that the application of phase transfer catalyzed synthesis to polycondensation has high potential value. With the proper choice of conditions, activated dihalides react readily with divalent nucleophiles including bisphenols, dithiols, and active methylene compounds in organic solvent-aqueous alkaline solution system to yield various types of condensation polymers such as polysulfonates, polyphosphonates, polyethers,7 polysulfides,S 10,18,19 and carbon-carbon chain polymers.14,15... 

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