High heat deflection temperature

An all aromatic polyetherimide is made by Du Pont from reaction of pyromelUtic dianhydride and 4,4 -oxydianiline and is sold as Kapton. It possesses excellent thermal stabiUty, mechanical characteristics, and electrical properties, as indicated in Table 3. The high heat-deflection temperature of the resin limits its processibiUty. Kapton is available as general-purpose film and used in appHcations such as washers and gaskets. Often the resin is not used directly rather, the more tractable polyamide acid intermediate is appHed in solution to a surface and then is thermally imidi2ed as the solvent evaporates. 

Besides high mechanical strength, polyester LCPs exhibit excellent thermal and chemical resistance, high heat deflection temperature, low mold shrinkage,... 

PCT forms the basis of a family of reinforced, crystalline plastics for injection molding. As mentioned above, the high melting point of the polymer is a key property, as this results in high heat deflection temperatures (HDTs) in glass-fiber-reinforced formulations. Good toughness, flow into the mold, and rapid crystallization are also important in these applications. 

PSU/PC alloys offer a combination of high heat deflection temperature steam and hot-water resistance ability to be autoclaved electrical properties and dimensional stability. Suitable grades can be classified VO in the UL94 fire rating and can be used for food and drinking water contact. 

Glass fibre reinforced PSU/PBT alloys offer good electrical properties combined with high heat deflection temperatures and a VO classification in the UL94 fire rating. 

Allylic plastics, which are produced by the polymerization of diallyl phthalate, have high heat deflection temperatures and high strengths. These cross-linked polyesters have solvent- and corrosion-resistant properties similar to those cited for alkyds. The properties of allylic plastics are shown in Table 15.3. 

Because of the stiffening effects of the phenyl and carbonyl groups, PEEK has a high heat deflection temperature (300 C). This high-performance polymer has high strength and excellent resistance to solvents. 

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. 

POLYARYLATES. These are clear, amorphous thermoplastics that combine clarity, high heat deflection temperatures, high impact strength, good surface hardness, and good electrical properties with inherent ultraviolet stability and flame retardance. No additives or stabilizers are required to provide these properties. Polyarylates are aromatic polyesters that are manufactured from various ratios of iso- and terephthalic acids with bisphenol A.1 The resultant products are free-flowing pellets which can be processed by a variety of thermoplastic techniques in transparent and... 

PPSUs provide excellent toughness, hydrolytic stability, creep resistance, high heat deflection temperature [204C (399F)] at 1.82... 

The purpose of this research is to synthesize a series of thermotropic liquid crystalline PECs consisting of HBA, DHBP, and carbonyl units with good melt processability and high heat deflection temperatures. The carbonate linkage is expected to reduce LCTT without reduction of the chain rigidity and heat resistance. 

The processing properties are improved when polylmides are produced from meta substituted diamines.(— A new amorphous polyether-imide (Ultem) with a high heat deflection temperature has been introduced by the General Electric Co. 

Because of low cost, high heat deflection temperature (HDT (104°C)), notched impact resistance, improved low temperature impact and flexibility, weather resistance, flame retardancy, and impact resistance, the PP/EPDM blend has got a widespread applications. These unique characteristics of this thermoplastic elastomer blend make it an attractive alternative to conventional elastomer in a variety of markets such as automobile industries, wire, cable insulator, automobile bumpers and fascia, hose, gaskets, seals, weather stripping, among others. 

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