High-temperature polymer polysulfone

Formed multilayer barrier packages, eg, trays, bowls, and cans from coextruded PP/PVDC/ PP, are being developed for soups and entrees that can be stored at ambient temperatures and heated to serving temperature in a microwave oven. Coextrusions of high performance, high temperature polymers, such as polyether-imide and polysulfone, for dual-oven containers capable of withstanding conventional bake-oven temperatures of 204-232°C are being tested. 

Li M, Scott K (2011) A polytetrafluoroethylene/ quatemized polysulfone membrane for high temperature polymer electrolyte membrane fuel cells. J Power Sources 196 1894-1898... 

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. 

Thermal, thermal-oxidative 674 Polystyrene, see Styrene polymers Polysulfone. see High-temperature polymers Polytetrafluoroethylene. see Fluoropolymers Polytrifluorochloroethylene. see Fluoropolymers Polyurethane... 

Polysulfones as a reinforcement in high temperature polymer blends... 

One of the primary rationales for producing blends of polysulfone with other polymers is to use the polysulfone to impart separation and membrane capabilities to the material and for the second polymer to provide higher temperature performance than is possible with the use of the polysulfone alone. For example, in the next section of this chapter, blends of polysulfone with other high temperature polymers such as polyimides (Pis) and polybenzimidazole (PBl) will be discussed. Much of that effort is focused on the production of miscible blends that can be fabricated into both symmetric and asymmetric membranes. Later sections of this chapter will focus on the use of polysulfone in mixtures to modify other properties of polymers, particularly the fracture and impact behaviors. 

Issues in blending polysulfone with other high temperature polymers... 

Polymers are used as inserts for pins and contacts. Important properties of the commonly used insert materials have been compiled (31). Polysulfones are high temperature thermoplastics that have high rigidity, low creep, excellent thermal stabiHty, flame resistance, low loss tangents, and low dielectric constants. The principal weakness of polysulfones is their low chemical resistance. 

Acrylic ESTER POLYMERS Acrylonitrile POLYMERS Cellulose esters). Engineering plastics (qv) such as acetal resins (qv), polyamides (qv), polycarbonate (qv), polyesters (qv), and poly(phenylene sulfide), and advanced materials such as Hquid crystal polymers, polysulfone, and polyetheretherketone are used in high performance appHcations they are processed at higher temperatures than their commodity counterparts (see Polymers containing sulfur). 

Electrical Properties. Polysulfones offer excellent electrical insulative capabiUties and other electrical properties as can be seen from the data in Table 7. The resins exhibit low dielectric constants and dissipation factors even in the GH2 (microwave) frequency range. This performance is retained over a wide temperature range and has permitted appHcations such as printed wiring board substrates, electronic connectors, lighting sockets, business machine components, and automotive fuse housings, to name a few. The desirable electrical properties along with the inherent flame retardancy of polysulfones make these polymers prime candidates in many high temperature electrical and electronic appHcations. 

The presence of aromatic groups in polymers greatly reduces their radiation sensitivity. Aromatic polysulfones are commercially important engineering plastics with high temperature resistance and also show good radiation resistance (16). Development of polymers with improved radiation resistance should be possible by copolymerization of other aromatic structures into the chain. 

Polysulfones are both aliphatic and aromatic polymers that are resistant to high temperatures and are very stable. 

Th-FFF can be applied to almost all kinds of synthetic polymers, like polystyrene, polyolefins, polybutadiene, poly(methyl methacrylate), polyisoprene, polysulfone, polycarbonate, nitrocelluloses and even block copolymers [114,194,220]. For some polymers like polyolefins, with a small thermal diffusion coefficient, high temperature Th-FFF has to be applied [221]. Similarly, hydrophilic polymers in water are rarely characterized by Th-FFF, due to the lack of a significant thermal diffusion (exceptions so far poly(ethylene oxide), poly(vi-nyl pyrrolidone) and poly(styrene sulfonate)) [222]. Thus Th-FFF has evolved as a technique for separating synthetic polymers in organic solvents [194]. More recently, both aqueous and non-aqueous particle suspensions, along with mixtures of polymers and particles, have been shown to be separable [215]. 

Improvement of surface hardness of some polymers by radiation processing at high temperatures — Gamma-ray or electron beam irradiation at high temperature and at a small dose improved the Rockwell hardness and resistance to wear for polycarbonate and polysulfone. The effective temperature during irradiation was the glass transition temperature of respective polymer, and the dose at maximum hardness was only 3-5 kGy [3], The improvement in hardness and wear resistance was supposed to be dense... 

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