Polyether imide properties

Among these methods, incorporation of thermoplastics has been highlighted as a new approach to enhance the toughness of thermosets without significantly lowering the desirable properties. Rigid thermoplastics with high Tg, such as polyethersulfone [11-16], polyether-imide [17-19], and polysulfone [20-23], were frequently used in this approach. 

Polyimide (PI) caps all other polymers in its temperature range of use (-200 to 260 °C in air short-time even up to 500 °C). Because of its high price, it is used in special cases only, such as space vehicles, nuclear reactors and some electronic parts. Newer developments, related to polyimide, are the polyether imides (e.g. Ultem ), polyester imides and polyamide imides (e.g. Torlon ), all with very good mechanical, thermal and electrical properties and self-extinguishing. 

Recently much effort has been made to induce liquid crystallinity in polyimides. Kricheldorf et al., Chen et al., and Sato et al. have suggested that an aromatic im-ide ring may be an excellent mesogen through their studies on thermotropic liquid-crystalline polyimide-esters [41-54] and polyimide-carbonates [55, 56]. Some thermotropic properties of aromatic polyether-imides have also been reported by Asanuma et al. [57]. 

EP 323142 (European) 1989 Ternary polyether ketone blend wire insulations Pirelli General PLC, UK CK Alesbury, RJ Murphy Formulation shows excellent stress craze resistance, flexibility and flame resistance Blends of polyarylene ether ketones, polyether imides and polyfimide siloxanes) were coated onto wire for solvent resistance, O index and abrasion resistance. Blends without siloxane-imide copolymer did not meet these properties... 

In addition to the polybenzimidazole blends with imide-siloxanes, it was also demonstrated that other different polyether imide-siloxane-segmented copolymers of variable composition could be used to modify semi-crystalline polyether ketones (PEEK) by presumably an analogous mechanism. The mechanical properties and transition temperatures of those systems have been reported [124,125], and would appear to be additional suitable candidates for the harsh outer space environment (see Table 4 and Fig. 21). 

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. 

Polyether-imide (PEI) is an amorphous thermoplastic, with an excellent balance of physical properties and dimensional stabilities. PEI can be nsed with the fnll spectrum of sterilisation methods. Surgical probes that are subjected to repeated cleaning and sterilisation are their typical preferred application as a medical plastic. 

S.M.. Zaidi, S. D. Mikhailenko, S. Kaliaguine, Electrical properties of sulfonated poly ether ketone/polyether-imide blend membranes doped with inorganic acids. Journal of Polymer Science Part B Polymer Physics 38 (2000) 1386-1395. 

Synthesis and Study of Properties of Aromatic Polyether-Imides on The Basis of Derivatives of Chloral and DDT With Use of... 

Synthesis and Study of Properties of Aromatie Polyether-Imides... 

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). 

Property Polysul- phone Udel Poly ether sulphone Victrex Poly- phenylene sulphide Ryton Polyether- imide Ultem Ultem +20% glass reinforced... 

In another example,1 1 a problem with poor physical properties of molded fluoroplastics was overcome. Transfer molded material was found to have low modulus of elasticity above 150°C and prone to irreversible cold flow. The solution involved embedding a metal or plastic insert as a core material in the mold. The choice of the core material depended on the end use performance requirements. An engineering plastic core was found preferable examples included polyetherether ketone (PEEK), polyphenylene sulfide (PPS), and polyether imide (PEI). Polytetrafluoroethylene bearers were placed in the mold to keep the core material away from the walls of the mold. No special cavity modifications were required. Any hot-melt fluoroplastic could be molded surrounding the insert examples include PVDF, FEP, ETFE, PFA, ECTFE, and PCTFE. 

Polymer Specimens. The materials used in this work were polyimide (PI),polyamide-imide (PAl), polyether-ether-ketone (PEEK), polyphenylene sulfide (PPS) and polyether sulphone (PES). The chemical formulas and physical properties of the specimen polymers are summarized in Table I. The specimen polymers, except PPS, were unfilled while the PPS specimen was filled with glass fiber of Uo wt. %. PAI and PES are amorphous polymer with considerably high glass temperature. The polymers, except PI, can flow at hi temperatures and allow the use of injection molding. 

The cured or fully imidized polyimide, unlike the poly(amic acid), is insoluble and infusible with high thermooxidative stability and good electrical-insulation properties. Thermoplastic polyimides that can be melt processed at high temperatures or cast in solution are now also available. Through an appropriate choice of the aromatic diamine, phenyl or alkyl pendant groups or main-chain aromatic polyether linkages can be introduced into the polymer. The resulting polyimides are soluble in relatively nonpolar solvents. 

Finally Table 1 summarize some properties of the most widely used matrices to composites including thermosets ( xy and phenolics), amorphous thermoplastics (Poly-ether-imide and poly-amide-imide) and semicrystalline ermoplasdcs (Polyether-ether-ketone, poly-phenylene-sulfide and poly-imide). 

Considerable attention has been devoted to the preparation of fluorine-containing polymers because of their unique properties and high temperature performance (I). Recently we reported the preparation and characterization of novel fluorine-containing polyimides and polyethers which exhibit low moisture absorption and low dielectric constants (2, 3). Fluorinated polyimides absorb 1 wt% water and have dielectric constants of about 2.8 (all dielectric constants reported in this paper were measured at 10 kHz) vtdiereas their non-fluorinated analogs absorb as much as 3 wt% water and have dielectric constants of about 3.2. Fluorinated polyarylethers, which are free of polar groups such as ketones, imides and sulfones, absorb as little as 0.1 wt% water and have dielectric constants less than 2.8. 

In order to improve the mechanical properties and the heat resistance of TPE-A, other links have been investigated. For instance, a poly(ether-6-amide) with an imide link was prepared by reacting polyamide-forming monomers and a diamino polyether together with trimellitic anhydride [61]. Naphthalene-1,2,5-tricarboxylic acid can also be used for this purpose. 

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