New silicon‐containing heterocyclic polyimides

Abstract

New aromatic polyimides and polyamide‐imides with phenylquinoxaline rings and dimethylsilane units have been synthesized by solution polycondensation reaction of aromatic diamines containing phenylquinoxaline units with bis(3,4‐dicarboxyphenyl)‐dimethylsilane dianhydride, or with a diacid chloride resulting from the reaction of this dianhydride with p‐aminobenzoic acid. These polymers were easily soluble in organic solvents, such as N‐methylpyrrolidinone and dimethylacetamide, and showed high thermal stability with decomposition temperature being above 440°C and glass transition temperature in the range of 245‐285°C. Very thin coatings were deposited from polymer solutions onto silicon wafers and exhibited smooth, pinhole‐free surface in atomic force microscopy investigations. Some of these polymers showed blue fluorescence in solution and films, with a maximum in the range of 415‐425 nm.

Polymers containing phenylquinoxaline rings

“…39 The light emitting ability of poly(phenylquinoxalines) 19a-d containing silicon and imide rings was estimated on the basis of photoluminescence spectra recorded for polymer solutions in N methylpyrrolidone or for spin coated films after irradiation with UV light. 25, 28 The UV absorption spectra of these polymers in solutions showed maxima in the range of 363-374 nm, their behaviors being rather similar, although an aromatic radical (Ar) with a different extent of conjugation had been intro duced between the two phenylquinoxaline units (Table 4). Therefore, the absorption properties of the polymers are mainly determined by the phenylquinoxaline rings.…”

“…33 Simi larly, polycondensations with dianhydride 8 and diacid chlorides 9 and 10 has given silicon containing polymers, poly[(phenylquinoxaline)amides] 16, 34-36 17, 37 and 18, 38 poly[(phenylquinoxaline)imides] 19, 25,28 and poly[phe nylquinoxaline(imide)amides] 20. 28 The polymers with amide groups 11-13, 16-18, and 20 were prepared by low temperature polycondensa tion of di(aminophenyl)quinoxalines 1-3 with diacid chlorides 4, 5, 7, 9, 10. A powdered diacid chloride was…”

Structural symmetry breaking of silicon‐containing poly(amide‐imide) oligomers and its relation to electrical conductivity and Raman‐active vibrations

“…Silicon‐containing aromatic polymers23, 24 have attracted much scientific and technological interest, because of their potential application in the production of optoelectronic materials. Silicon, when it is placed among aromatic neighbors, introduces a σ–π conjugation and therefore favors electron transport along macromolecular chains 25.…”

Polyesters based on two silarylene or germarylene moieties: Synthesis under phase‐transfer conditions

“…Silicon‐containing polymers in which the Si atom is bonded to four organic groups have been described by several authors. In this sense, the properties of polyamides, polyimides, polyesters (PEs), polycarbonates, polythiocarbonates, and others have been described and related to the molecular structure of the polymer chain 1–13. These works have reported a higher electronegativity of the Si atom in front of the C atom; as a result, the CSi bond has an ionic character with an increase in the solubility of polymers with silyl aromatic groups, but high thermal stability is maintained 3, 7.…”

“…In this sense, the properties of polyamides, polyimides, polyesters (PEs), polycarbonates, polythiocarbonates, and others have been described and related to the molecular structure of the polymer chain. [1][2][3][4][5][6][7][8][9][10][11][12][13] These works have reported a higher electronegativity of the Si atom in front of the C atom; as a result, the CASi bond has an ionic character with an increase in the solubility of polymers with silyl aromatic groups, but high thermal stability is maintained. 3,7 In this sense, the replacement of a carbon atom bonded to four organic groups by silicon or germanium leads to an improvement in the ionic character of the polymer chain because of the difference in the electronegativity between these atoms and C atoms, Si and Ge being stronger acceptor atoms.…”