Polyaryl ether sulfone

PEEK-polyaryl ether sulfone blends gave two Tg values corresponding to a PEEK rich blend and a polyaryl ether sulfone rich blend. Binary polylactide-polyvinyl pyrolidone blends also exhibited two Tg values. 

Amoco [7] reported several polyaryl ether-sulfones to be miscible with each other. The miscible blend comprises a 1,4-arylene unit separated by ether oxygen and another resin 1,4 arylene separated by an SO2 radical. The miscible blends showed a single glass transition temperature in between the constituent values. The blend was transparent. These can be used for printing wiring board structures, electrical connectors, and other fabricated articles that require high heat and chemical resistance and good dimensional and hydrolytic stability. 

Several polyaryl ether-sulfones were found to be miscible with each other (Figure 1.2). AMS-AN copolymers have been found to be miscible with PMM A and with PEM A, and the blends exhibit LCST-type behavior. PS forms a miscible blend with polyxylenyl ether and with tetramethyl bisphenol polycarbonate, and PPO and P-sCL (poly-epsilon caprolcatone). SAN forms miscible blends with PMMA and PVC. 

Raman spectra of polyaryl ether ether sulfone and polyaryl ether sulfones. 

Solvent for Displacement Reactions. As the most polar of the common aprotic solvents, DMSO is a favored solvent for displacement reactions because of its high dielectric constant and because anions are less solvated in it (87). Rates for these reactions are sometimes a thousand times faster in DMSO than in alcohols. Suitable nucleophiles include acetyUde ion, alkoxide ion, hydroxide ion, azide ion, carbanions, carboxylate ions, cyanide ion, hahde ions, mercaptide ions, phenoxide ions, nitrite ions, and thiocyanate ions (31). Rates of displacement by amides or amines are also greater in DMSO than in alcohol or aqueous solutions. Dimethyl sulfoxide is used as the reaction solvent in the manufacture of high performance, polyaryl ether polymers by reaction of bis(4,4 -chlorophenyl) sulfone with the disodium salts of dihydroxyphenols, eg, bisphenol A or 4,4 -sulfonylbisphenol (88). These and related reactions are made more economical by efficient recycling of DMSO (89). Nucleophilic displacement of activated aromatic nitro groups with aryloxy anion in DMSO is a versatile and useful reaction for the synthesis of aromatic ethers and polyethers (90). 

STYRENE-ACRYLONITILE AMINOPLASTICS POLYARYL ETHER POLYARYL SULFONE... 

We initiated our work by examining nucleophilic aromatic substitution, a somewhat difficult reaction to effect in other than activated aryl halides as substrates. It occurred to us that if polyhaloaromatics could be made to suffer disubstitution under mild solid-liquid PTC conditions, then they might be used as comonomers with a variety of bisnucliophiles to prepare halogenated polyaryl-ethers, sulfides, sulfone-ethers as well as other interesting polymers which are at present synthesized only with some difficulty. 

Various kinds of engineering thermoplastics such as polyether sulfone, polyether imide, polyaryl ether ketone, and polyphenylene oxide have been studied as toughening agents for... 

Synthesis. Five different polyaryl ethers were made from the condensation product, resulting from the reaction of phenol and levulinic acid, commonly referred to as diphenolic acid, and one or more of the following monomers bisphenol A, dichlorodiphenyl sulfone, 2,6-dichloro-benzonitrile, and 4,4 -difluorobenzophenone. The resulting polymers were subsequently methylated such that the common monomer becomes (1) ... 

Figure 18.18 Map of dielectric properties of engineering plastics. Among engineering plastics, SPS (impact modified and GF-reinforced HB and IR grades) has very low dielectric dissipation factor and dielectric constant following those of fluorocarbon polymers. PSF, polysulfone PPE, poly(phenylene ether) PES, poly(ether sulfone) PAr, polyarylate...

Aromatic copolyester TP Polyaryl ether Polyaryl sulfone (PAS)... 

All commercialized polyether sulfones have aromatic groups, sulfone residues, and ether groups in the main chain. Depending on the company producing them, they are known as polysulfones, polyaryl sulfones, polyether sulfones, or polyaryl ethers. The five commercially available polyether sulfones consist of a polymer with the monomeric unit, I, a polymer with the monomeric unit I in excess over the monomeric unit II, an alternating copolymer of I and II, a copolymer of I and II with II in excess, and a polymer with the repeating unit III ... 

Dynamic-mechanical data for PEI given in Table 13.3 indicates a /3 relaxation at about 340-380 K and a y relaxation at about 160-186 K. These relaxations are comparable to those cited above for Kapton although they occur at slightly lower temperatures. As in the case of Kaptrni, the y-relaxational peak of PEI is reported to increase in intensity with sorbed water [63]. From comparison of the dielectric spectra of PEI, poly(ether sulfone) (PES) (see Section 13.1.6), and polyarylates with their corresponding low-molecular-weight compounds, Schartel and Wendorff [64] have concluded that both intrachain and interchain interactions contribute to the y relaxation in these polymers. 

Parylenes Polyaryl ether Polyaryl sulfone Polycarbonates... 

Fig. 11.10 Water uptake isotherms of various ionomers and sulfuric acid at 80 C. Dowex 50 is an ion-exchange resin made of 4% cross-linked polystyrene divinyl benzene BPSH 40 is a 2-mil 40% randomly sulfonated biphenol sulfone 700 EW PFSA is a 1-mil membrane with a structure similar to Nafion Nafion 112 is a 2-mil extruded membrane and, PAEK triblock is a 1-mil triblock polyaryl ether ketone with a sulfonated middle block (Reproduced from C.K. Mittelsteadt and H. Liu. [30] by permission from John Wiley Sons)...

Dimethyl sulfoxide is used as a reaction solvent in the polymerization of acrylonitrile with a vinyl monomer (e.g., styrene). Reaction of diisocyanates and polyols or polyamines dissolved in DMSO yield solutions of the polyurethanes. Mixtures of DMSO and water are used as a spinning solvent for polymer fibers. Polyaryl ether polymers are formed from DMSO solutions containing the reactants bis(4,4-chlorophenyl sulfone) and the disodium salt of dihydroxyphenol. 

High-temperature thermoplastics, such as polysulfone, polyether sulfone, polyphenylene sulfide, polyether imide, polyaryl ether ketone, and polyphenylene ether are processed at high temperatures (some above 300 °C). Here, the limit of pyrolysis is almost reached. Degradation and cross-linking as well as discoloration can occur thermal-oxidative and thermal-mechanical degradation under processing conditions have not been sufficiently investigated [38]. 

Aromatic polymers have many desirable properties such as good lap shear strength, thermal stabihty, and tensile strength, which make them useful for a wide variety of applications. The term aromatic polymer is used herein to mean a polymer, which has aromatic groups incorporated in the repeat unit of their backbone chain. Such polymers include polyimides (Pis), polyetherimides, polysulfones, polyether sulfones, polyaryl ether ketones, polycarbonates, poly-arylates, and the like [20]. 

Fortunately, the deficiencies of both the classic thermosets and general purpose thermoplastics have been overcome by the commercialization of a series of engineering plastics including polyacetals, polyamides, polycarbonate, polyphenylene oxide, polyaryl esters, polyaryl sulfones, polyphenylene sulfide, polyether ether ketones and polylmides. Many improvements in performance and processing of these new polymers may be anticipated through copolymerization, blending and the use of reinforcements. 

The development of polyaryls, in particular polyetherketones (PEEK), as a substitute of perfluorinated polymers was mainly based on cost and stability considerations [1]. Sulfonated polyetherketones has been found to be durable under fuel cell operation conditions over several thousand hours [185]. Victrex Company is the main producer of PEEK polymer and its sulfonation can be performed directly on the polymer backbone or by polymerization of sulfonated monomers [7]. Hoechst-Aventis and Eumatech commercialize sulfonated PEEK (sPEEK) and sulfonated poly(phtalazinone ether ketone) (sPPEK) membranes for fuel cell applications [3]. 

Polyaryl sulfone consists mainly of phenyl and biphenyl groups linked by thermally stable ether and sulfone groups. It is distinguished from polysulfone polymers by the absence of aUphatic groups, which are subject to oxidative attack. This aromatic structure gives it excellent resistance to oxidative degradation and accounts for its retention of mechanical properties at high temperatures. 

High-performance engineering thermoplastics have recently assumed hicteas-ing importance due to their exceptional properties at elevated tenqioatures. A number of such spedalty polymers has been introduced into the market for higili-temperature applications and examples of some of the outstanding ones are poly phenylene oxide (PPO), poly fdienylene sulfide (PPS), polyetlier sulfone ES), polyaryl sulfone (PAS), polyether ether ketone (PEEIQ, polyetherimide (PEl, and polyarylate (PAr). 

Polyether sulfone (RBS) and polyaryl sulfone (PAS) comprise a class of en-gineeting thermoplas with h thermal, oxidative, and hydrolytic stability and a good resistance to aqueous mineral adds, sdkali, salt solutions, ofls and greases, whereas polyethm ether ketone (PEEK) has attractive properties like good abradon resistance, low flammability and emission of smoke and toxic... 

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