Temperature polyimides

Table 2. Properties of High Temperature Polyimide Films...

From these results, it may be concluded that the aliphatic polyimides, especially the pyromellitic acid-based polyimides P-XPM with Tm values around 300 °C, are promising candidates as moldable high-temperature polyimide resins useful for industrial applications. 

Edelman R (1985) A new high temperature polyimide adhesive use with kapton film. Natl SAMPE Symp Exhib (Proc) 30 (Adv Technol Mater Processes) 230... 

We report herein LPD titania films deposited on three kinds of polyimides two high-temperature polyimide resins (PMR-15 and Kapton ) and a bismaleimide glass fiber composite (BMI). We have examined different solution conditions and different surface priming strategies. We have also learned to minimize film cracking by carefully controlling the drying process. 

Sacher, E., and Susko, J. R., "Water Permeation of Polymer Films III, High Temperature Polyimides", J. Appl. Polymer Sci., 26,679-686 (1981). 

Sekkat, Z., Knoesen, A., Lee, V. Y., and Miller, R. (1997). Observation of reversible photochemical blow out of the third-order molecular hyperpolarizability of push-pull azo dye in high glass transition temperature polyimides. J. Phys. Chem. B 101, 4733-4739. 

Vespel [Du Pont], TM for fabricated parts, based on polyimide resin and diamond abrasive wheels formulated with a high-temperature polyimide binder. 

From the area of polymer dielectrics, a sample is presented here using a commercially available and (from many microelectronic applications) well-known high-temperature polyimide. The deposition and the subsequent curing process have been described in Section 18.2.3, resulting in a 190 nm thick insulating film that showed a good chemical resistance towards diluted developer solution and acetone, so that the cathode-sputtered Au drain and source contacts can be structured as described in Section 18.2.1. The 30 nm thick pentacene layer is thermally evaporated at a deposition rate of about 0.1 nm/s and a process pressure of 1 x 10 mbar. 

POLYIMIDE DEPOSITION PHOTOLITHOGRAPHY - POLYIMIDE HIGH TEMPERATURE POLYIMIDE BAKE (700°C)... 

Stable at relatively high temperatures. Polyimides, such as polybenzimidazole, etc., are at least in part ladder polymers and are also stable at relatively high temperatures. 

Polyimides have been used up to 100 h at 600°F (315.6°C). They have been used as a transparent head cover for fire fighters and as excellent flame- and high-temperature-resistant foams, which can be used as structurally stable insulation materials at high temperatures. Polyimide/glass fiber composites have many uses in the electronics and aerospace industries and in other high-performance applications. 

Where the traditional high temperature polyimides such as PMR-15 and AMB-21 typically have minimum viscosities of around 2000 cPs at temperatures up to 2IOC, the Foster Miller resin has a viscosity of about 300 cPs at 110-150C, with good pot life. It can be processed by RTM, and flat panels have been molded by conventional techniques without the use of solvents. Foster Miller has linked with Cyclopss Corporation, Salt Lake City, USA to commercialize the system and a joint company, Pyrogonn LLC, will control the process patents and work to extend the system into new markets. 

Scola DA, Simone CD. Low viscosity melt processable high temperature polyimides. US patent 6911519, assigned to University of Connecticut, Earmington, CT 2005. 

According to the results of these combined studies, the incorporation of elastomers into a high-temperature polyimide thermoset, LARC-13, shows much potential for broadening the applicability of this polymer system as an adhesive. 

Sekkat, Z., Wood, J., Aust, E. F, Knoll, W., Volksen, W. and Miller, R. D., Light induced orientation in high glass transition temperature polyimide with polar azo dyes in the side chain, J. Opt. Soc. Am. B, 13, 1713-1724 (1996). 

Back in the mid-70 s when the polyetherimide chemistry and physical properties were under study, considerable skepticism and prejudice existed. Previous failures to melt process high temperature polyimides were at the roots of our concerns. 

High-temperature polyimides are used as an excellent electrical insulator in microelectronic devices. This is due to the fact that the CTCs formed in PI films are classified into a category of weak CT complex, and therefore, have practically no contribution to the charge-separated structure at the ground state. Fainshtein et al. [116] showed that the increases in pressured and temperature cause a decrease in the electrical resistance in the dark for Pis derived from a fixed diamine (ODA) with PMDA, BTDA, and 3,3 4,4 -diphenylsulphonetetracarboxylic dianhydride. These results were explained in terms of an electron conductance mechanism based on interchain CTC formation. 

The most general method for the preparation of high temperature polyimides is based on the reaction between an aromatic diamine and an aromatic dianhydride or tetracarboxylic acid. This proceeds via the formation of the intermediate polyamic acid which in further heating undergoes a ring closure condensation reaction leading to imide formation. The reaction is as follows... 

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