Polyimide composite structures

The applications for addition polyimides are for electronic/electrical materials such as printed circuit boards and insulators, as matrix resins for structural composites in aircraft and as thermal insulation materials. Recently the market for polyimide based structural composites has suffered from the termination and reduction of military aircraft programs. However, the possible emergence of the High Speed Civil Transport program (HSCT) may offer an opportunity for addition polyimides (2). 

Matrimid . [Qba-Geigy/Plastics] Thermoplastic polyimides for structural composites and adhesives. 

The preparation of composites prepared by high temperature decomposition reactions have mainly concentrated on polyimides and reactive inorganic additives (e.g., simple salts and complexes). In many cases polymer-metal composites have been unintentionally produced by workers whose primary goal was the modification of polyimide properties by incorporation of metal ions. For example, approximately 30 years ago Angelo briefly reported in a patent the addition of metal ions to several types of polyimides for the purpose of forming particle-containing transparent polyimide shaped structures. Ten years... 

CLASS Polyimides thennoset resins addition polyimides composite matrix resins STRUCTURE O O... 

Where the filter medium is in the form of a needle felt (as found in pulse-jet collectors), some manufacturers have offset the deficiencies found in some of the above fibres by producing composite structures, e.g. polyar-amid, polyimide or PPS fibres on the surface of the felt with a PTFE scrim or base-cloth providing a framework of support. Although under certain physicochemical conditions the surface fibres become degraded, it has been found that the skeleton of support provided by the PTFE base-cloth is often sufficient to enable satisfactory performance to continue. 

K. Tadanaga, Y. Michiwaki, T. Tezuka, A. Hayashi, M. Tatsumisago, Structural change and proton conductivity of phosphosilicate gel-polyimide composite membrane for a fuel cell operated at 180 °C, J. Membr. Sci. 324 (1)... 

Yudin, V. E. and V. M. Svedichnyi. 2010. Effect of the structure and shape of filler nanoparticles on the physical properties of polyimide composites. Russian Journal of General Chemistry 80 (10) (November 26) 2157-2169. doi 10.1134/S1070363210100452. http //www.springerlink.coni/index/10.1134/S1070363210100452. 

Bonding high-performance composite structures, such as those in aerospace, are very different than bonding metal structures in that the matrix polymer, such as epoxy, bismaleimide, or polyimide, can be used as the adhesive as well so that there is excellent chemical compatibility and good adhesion between the substrate and the adhesive (Pate 2002). Therefore, there is much less reliance on mechanical or physical bonding. 

Because of this continued emphasis on adhesive bonding technology development over the years, the airframes of modem front-line aircraft such as the B-2 bomber and the F-117 and F-22 fighters are largely structurally bonded advanced composites. They tend to be comprised of materials that are more advanced (expensive) than commercial aircraft such as carbon and boron fiber reinforcements with cyanate esters, bismaleimides, polyimides or other high-temperature resin matrices and adhesives. 

Molar mass boosting, 89 Molecular composites, polyimide, 269 Molecular structure, of polyurethanes, 209-217... 

Syntactic foams are composites made of micro-balloons or hollow macrospheres bound into a plastic matrix. The polyimide syntactic foams are used in specific electronic equipment for microwave and RF applications. They act as structural, dielectric and heat-barrier materials. Micro-balloons can be made of polyimides for special applications. 

The data indicate that the properties of the lower glass transition temperature metal ion modified polyimides are altered more than the properties of the higher glass transition temperature metal ion modified polyimides. Extraction removes both cobalt and chlorine from the films and slightly increases bulk thermal stability and both surface resistivity and bulk electrical resistivity. Details pertaining to the structure, analysis and properties of these novel gradient composites are discussed. 

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