Low dielectric fluorinated poly(phenylene ether ketone) film and coating

The present invention relates to film and coating materials prepared from novel fluorinated poly(phenylene ether ketones). A fluorinated poly(phenylene ether ketone) is prepared by reacting a bisphenol with 1,1,1,3,3,3 hexafluoro-2,2-bis 4-(4-halobenzoyl) phenyl propane (wherein halo is fluoro or chloro), which is a novel monomer formed as the reaction product of halobenzene (wherein halo is fluoro or chloro) and 1,1,1,3,3,3 hexafluoro-2,2-bis (p-chloro formyl phenyl) propane. Especially beneficial results of this invention are that films and coating materials prepared from the novel fluorinated poly(phenylene ether ketone) are essentially optically transparent/colorless and have a lower dielectric constant than otherwise comparable, commercially available poly(phenylene ether ketones). Moreover, unlike the otherwise comparable commercially available materials, the novel fluorinated poly(phenylene ether ketones) of the present invention can be solution cast or sprayed to produce the films and coatings. Furthermore, the long term thermal stability of the polymers of the present invention is superior to that of the commercially available materials

Unexpected Thermal Conversion of Hydroxy-Containing Polyimides to Polybenzoxazoles

An aromatic polyimide containing pendent hydroxyl groups ortho to the heterocyclic imide nitrogen was found to rearrange to a polybenzoxazole, with quantitative loss of carbon dioxide, upon heating above 490 degrees C in an inert atmosphere. A hydroxy-containing polyimide film based on 3,3\u27,4,4\u27-biphenyltetracarboxylic dianhydride (BPDA) and 3,3\u27-dihydroxy-4,4\u27-diaminobiphenyl (HAB) was pre pared and converted to a fully aromatic polybenzoxazole by heating at 500 degrees C for 1 h under nitrogen. The resulting polybenzoxazole film was found to be amorphous by small angle X-ray scattering (SAXS). The film also displayed excellent solvent resistance and good thermal stability by thermogravimetric analysis with 5% weight loss in nitrogen occurring at 625 degrees C. A hydroxy-containing imide model compound was also found to undergo thermal conversion to a bisbenzoxazole when heated above 400 degrees C under nitrogen. (C) 1999 Elsevier Science Ltd, All rights reserved

Soluble Poly(amide-imide)s Prepared by One-Pot Solution Condensation

A new one-pot procedure for imide-acid monomer synthesis and polymerization is reported for four new poly(amide-imide)s. Bisphenol A dianhydride (BPADA) was reacted with twice the molar amount of 3-aminobenzoic acid (3ABA) or 3-amino-methylbenzoic acid (3A4MBA) in 1-methyl-2-pyrrolidinone (NMP) and toluene mixture, and the amic acid intermediates cyclized in solution to give two diimide-containing dicarboxylic acid monomers. Without isolation, the diacid monomers were then polymerized with either 1,3-diaminomesitylene (DAM) or 1,5-diaminonaphthalene (1,5NAPda) using triphenyl phosphite-activation to give a series of four soluble poly(amide-imide)s, PAI. Isolation and purification of the dicarboxylic acid monomers was not necessary for formation of high molecular weight polymers as indicated by intrinsic viscosities of 0.64-1.04 dL/g determined in N,N-dimethylacetamide (DMAc). All of the PAI were soluble in polar aprotic solvents such as NMP, DMAc, and dimethyl sulfoxide (DMSO). Glass transition temperatures ranged from 243 to 279 degrees C by DSC, and 5% weight loss temperatures were above 400 degrees C in both air and nitrogen. Flexible films cast from DMAc were light yellow, transparent, and tough. (C) 1999 John Wiley & Sons, Inc

Thermal Conversion of Hydroxy-Containing Imides to Benzoxazoles: Polymer and Model Compound Study

A series of hydroxy-containing polyimides, containing pendent hydroxyl groups ortho to the heterocyclic imide nitrogen, were prepared via the solution condensation of aromatic dianhydrides with bisaminophenols. The polyimides were found to undergo thermal conversion to polybenzoxazoles upon heating between 350 and 500 degrees C under nitrogen or vacuum. The thermal conversion was accompanied by loss of carbon dioxide. No other volatile byproducts were detected by IR or NMR. Structures were confirmed by IR, solid-state NMR, and elemental analysis. Polybenzoxazole films, obtained by the thermolysis of solvent-cast poly(amic acid) or polyimide solutions, displayed excellent solvent resistance and good thermal stability. Insolubility of the polybenzoxazoles in all solvents tested indicates possible cross-linking. No crystallinity was observed by X-ray diffraction. Due to the insolubility of the resulting polybenzoxazoles, model compound reactions were also investigated. In the vapor phase at 400 degrees C, N-(2-hydroxyphenyl)phthalimide underwent intramolecular thermal conversion to 2-phenylbenzoxazole in 83% yield, emulating the polyimide reactions. Thermal conversion of N-(2-hydroxyphenyl)phthalimide in the melt at 400 degrees C resulted in the formation of intermolecular reaction products. The intermolecular reactions may be a source of possible cross-links, which would explain the insolubility of the polybenzoxazoles

Adamantane-Containing Polymers

Adamantane is a rigid ring system comprised of three fused chair conformation cyclohexane rings. Its excellent thermal stability, bulkiness, and tetrahedral geometry lead to improved physical properties such as stiffness, glass transition temperature (Tg), and solubility. Star polymers include polyaramids and polybenzoxazoles based on adamantane and biadamantane. All hydrocarbon three-dimensional networks use acetylene, phenylacetylene, or diphenylacetylene groups attached at the bridgehead positions with thermal polymerization or nickel catalyzed reactions of iodophenyl groups attached directly to the bridgehead positions. Pendent adamantane groups were incorporated into acrylates, phenolics, poly(phenylenes), and poly(ether ether ketones). Each type shows a large increase in Tg and thermal properties over the linear, unsubstituted polymer