Polyaryl sulfones properties

As shown in Table 15.8, polyaryl sulfones have excellent mechanical properties. The commercial products differ somewhat in properties, but all have high heat deflection temperatures (at least 175 C). These thermoplastic engineering polymers have excellent resistance to nonoxidizing acids, salts, and alkalis, and to polar solvents. They are attacked by nonpolar solvents such as benzene. 

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 increasing importance due to their exceptional properties at elevated temperatures. A number of such specialty polymers have been introduced into the market for high temperature applications and examples of some of the outstanding ones are polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polyether sulfone (PES), polyaryl sulfone (PAS), polyether ketone (PEEK), polyether imide (PEI) 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... 

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 polyesters having an amorphous molecular structure. Compared with other amorphous engineering plastics in terms of heat resistance, polyarylates are generally positioned between polycarbonate on the low side and sulfone and polyether polymers on the high side. Compared with crystalline and semi-crystalline engineering plastics, polyarylate resins offer better resistance to warping, and generally comparable mechanical properties. 

Blends comprising sulfone polymers and other middle- to high-temperature engineering resins with at least a partially aromatic backbone structure are feasible in many cases. Such blends include sulfone polymer blends with polycarbonates, some polyesters, polyarylates, poly-etherimides, and polyaryletherketones. Blends of PPSF with poly-aryletherketones such as PEEK or PEK are particularly interesting as these blends form very finely dispersed systems with synergistic strength, impact, and environmental stress cracking resistance properties [43, 44]. 

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]. 

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