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Yoshiyuki Oishi Masa-Aki Kakimoto Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1991,29(13):1925-1931
The polymerization of N,N′-bis(trimethylsilyl)-substituted aromatic diamines with 4-chloroformylphthalic anhydride in various solvents at a temperature range between 10 and 70°C afforded polyamide-amic acid trimethylsilyl esters having inherent viscosities of 0.8–1.4 dL/g. Transparent and flexible films of the silylated precursor polymers were obtained by casting directly from the polymer solutions. Desilylation of the silylated polymers with methanol resulted in the formation of the corresponding polyamide-amic acids. Subsequent thermal imidization of the silylated precursor polymers with the elimination of trimethylsilanol afforded yellow, transparent, and tough films of the aromatic polyamide-imides. The thermal conversion of the silylated precursor polymer to polyamide-imide proceeded almost as rapidly as that of the corresponding polyamide-amic acid prepared by a conventional method from the parent aromatic diamine and 4-chloroformylphthalic anhydride. 相似文献
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Summary Diethoxymethy][m-(trifluoromethyl)phenyl]silane and triethoxy[m-(trifluoromethyl)phenyl]silane were synthesized. 相似文献
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Several new Poly(ether-amide-imide)s were prepared by direct polycondensation reactions of 1,4-bis-[4-(trimellitimido)phenoxy]butane with various aromatic diamine. Two direct polycondensation techniques were used: direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone/triphenyl phosphite/calcium chloride/pyridine and direct polycondensation in a tosyl chloride/pyridine/N,N-dimethylformamide system. All the monomers and polymers were fully characterized by means of FTIR, 1H-NMR spectroscopy and elemental analyses and properties of the polymers including solution viscosity, thermal behavior and solubility were studied. 相似文献
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M. L. Keshtov A. L. Rusanov N. M. Belomoina A. K. Mikitaev G. B. Sarkisyan M. M. Begretov 《Russian Chemical Bulletin》1996,45(9):2240-2242
A series of new bis[p-(phenylethynyi)phenyl]hetarylenes was obtained by cross-coupling between heteroaromatic dibromides and phenylacetylene catalyzed by phosphine complexes of palladium in the presence of Cul and an organic base. Bis[p-(phenylethynyl)phe-nyl]hetarylenes were oxidized to the corresponding bis[p-(phenylglyoxalyl)phenylihetarylenes using the I2-DMSO system.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2359–2361, September, 1996. 相似文献
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Sheng‐Huei Hsiao Li‐Min Chang 《Journal of polymer science. Part A, Polymer chemistry》2000,38(9):1599-1608
A series of new poly(imide‐hydrazide)s and poly(amide‐imide‐hydrazide)s were obtained by the direct polycondensation of N‐[p‐(or m‐)carboxyphenyl]trimellitimide (p‐ or m‐CPTMI) with terephthalic dihydrazide (TPH), isophthalic dihydrazide (IPH), and p‐aminobenzhydrazide (p‐ABH) by means of diphenyl phosphite and pyridine in the N‐methyl‐2‐pyrrolidone (NMP) solutions containing dissolved CaCl2. The resulting hydrazide‐containing polymers exhibited inherent viscosities in the 0.15–0.96 dL/g range. Except for that derived from p‐CPTMI with TPH or p‐ABH, the other hydrazide copolymers were readily soluble in polar solvents such as NMP and dimethyl sulfoxide (DMSO). As evidenced by X‐ray diffraction patterns, the hydrazide copolymer obtained from TPH showed a moderate level of crystallinity, whereas the others were amorphous in nature. Most of the amorphous hydrazide copolymers formed flexible and tough films by solvent casting. The amorphous hydrazide copolymers had glass‐transition temperatures (Tg) between 187 and 233 °C. All hydrazide copolymers could be thermally converted into the corresponding oxadiazole copolymers approximately in the region of 250–400 °C, as evidenced by the DSC thermograms. The oxadiazole copolymers showed a significantly decreased solubility when compared to their respective hydrazide precursors. They exhibited Tg's of 264–302 °C and did not show dramatic weight loss before 400 °C in air or nitrogen. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1599–1608, 2000 相似文献
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Guey-Sheng Liou Sheng-Huei Hsiao 《Journal of polymer science. Part A, Polymer chemistry》1997,35(11):2273-2280
A new aromatic dicarboxylic acid, 1,4-bis (p-carboxyphenoxy)naphthyl ( 3 ), was synthesized by the reaction of p-fluorobenzonitrile with 1,4-naphthalenediol, followed by hydrolysis. Aromatic polyamides having inherent viscosities of 1.27–2.22 dL/g were prepared by the triphenyl phosphite activated polycondensation of diacid 3 with various aromatic diamines. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents including N,N-dimethyl-acetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and m-cresol. Transparent, tough, and flexible films of these polymers could be cast from the DMAc or NMP solutions. The cast films had tensile strengths ranging from 64–104 MPa, elongations-at-break from 6 to 10%, and initial moduli from 1.52 to 2.14 GPa. These polyamides had glass transition temperatures in the range of 195 to 240°C. Almost all polymers were thermally stable up to 400°C, with 10% weight loss being recorded above 480°C in air and nitrogen atmospheres. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2273–2280, 1997 相似文献
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Chin-Ping Yang Sheng-Huei Hsiao Jiun-Hung Lin 《Journal of polymer science. Part A, Polymer chemistry》1992,30(9):1865-1872
Various dicarboxylic acids with preformed imide rings were readily obtained by the condensation of ω-amino acids and aminobenzoic acids with trimellitic anhydride, and omega;-amino acids with pyromellitic dianhydride. New tetraphenylthiophene-containing poly(amide-imide)s having inherent viscosities of 0.58-1.54 dL/g were prepared by the direct polycondensation reaction of 2,5-bis(4-aminophenyl)-3,4-diphenylthiophene with the imide-containing dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. These polymers were amorphous and readily soluble in a variety of solvents such as dimethylacetamide (DMAc), dimethylformamide (DMF), and N-methyl–2-pyrrolidone (NMP), and could be easily solution cast into transparent, flexible, and tough films. Most of the poly(amide-imide)s showed clear glass transition on the heating traces of differential scanning calorimetry (DSC) in the range of 146–244°C. Almost all the poly(amide-imide)s exhibited no appreciable decomposition below 400°C, with 10% weight loss being recorded above 420°C in nitrogen. © 1992 John Wiley & Sons, Inc. 相似文献
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Synthesis and characterization of novel polyimides derived from pyridine-bridged aromatic dianhydride and various diamines 总被引:2,自引:0,他引:2
A new kind of pyridine-bridged aromatic dianhydride monomer, 4-phenyl-2,6-bis[4-(3,4-dicarboxyphenoxy)phenyl]-pyridine dianhydride (PPDA), was successfully synthesized by modified Chichibabin reaction of benzaldehyde and substituted acetophenone, 4-(3,4-dicyanophenoxy)-acetophenone (DCAP), followed by acidic hydrolysis of the intermediate tetranitrile and cyclodehydration of the resulting tetraacid. The pyridine-bridged aromatic dianhydride was employed to synthesized a series of new pyridine-containing polyimides by polycondensation with various aromatic diamines in N-methyl-2-pyrrolidone (NMP) via the conventional two-step method, i.e. ring-opening polycondensation forming the poly(amic acid)s and further thermal or chemical imidization forming polyimides. The inherent viscosities of the resulting polyimides were in the range of 0.49-0.63 dL/g, and most of them were soluble in aprotic amide solvents and cresols, such as N,N-dimethylacetamide (DMAc), NMP, and m-cresol, etc. Meanwhile, strong and flexible polyimide films were obtained, which have good thermal stability with the glass transition temperatures (Tg) of 223-256 °C, the temperature at 5% weight loss of 523-569 °C, and the residue at 700 °C of 52.1-62.7% in nitrogen, as well as have outstanding mechanical properties with the tensile strengths of 70.7-97.6 MPa and elongations at breakage of 7.9-9.7%. Wide-angle X-ray diffraction measurements revealed that these polyimides were predominantly amorphous. 相似文献
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New aromatic poly(amide-imide)s with high inherent viscosities were prepared by direct polycondensation reaction of diimide-diacid (I) and aromatic diamines using triphenyl phosphite in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved CaCl2. The bis(3-trimellitimidophenyl) phenyl phosphine oxide (I) was readily obtained by the condensation reaction of bis(3-aminophenyl) phenyl phosphine oxide (BAPPO) with trimellitic anhydride. The resulting poly(amide-imide)s showed high thermostability. Their decomposition temperatures at 10% weight loss in nitrogen atmosphere were above 532 °C and the anaerobic char yield at 800 °C ranged from 56% to 74%. Almost all the poly(amide-imide)s showed high glass transition temperature above 233 °C by differential scanning calorimetry (DSC) measurements. These polymers were readily soluble in various organic solvents and by their casting into transparent, tough and flexible films can be easily achieved. 相似文献
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A. Yu. Nikonov I. V. Sterkhova N. F. Lazareva 《Russian Journal of General Chemistry》2014,84(5):883-887
A series of N-[chloro(diorganyl)silyl]anilines RR′Si(NR″Ph)Cl (R, R′ = Me, Ph, CH2=CH, ClCH2, Cl(CH2)3; R″ = H, Me) was prepared via the reaction of diorganyldichlorosilanes with aniline or N-ethylaniline in the presence of triethylamine. 相似文献
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Teplý F Stará IG Starý I Kollárovic A Saman D Rulísek L Fiedler P 《Journal of the American Chemical Society》2002,124(31):9175-9180
An original approach to helicene frameworks exploiting atom economic isomerization of appropriate energy-rich aromatic cis,cis-dienetriynes has been developed. The new paradigm provides nonphotochemical syntheses of helicenes based on the easy, convergent, and modular assembly of key cis,cis-dienetriynes and their nickel(0)-catalyzed [2+2+2] cycloisomerization. The potential of the methodology is underlined by the syntheses of the parent [5]helicene (2), 7,8-dibutyl[5]helicene (23), [6]helicene (24), and [7]helicene (25). The approach can be adapted to prepare functionalized helicenes as exemplified by the eight-step synthesis of 7,8-dibutyl-2,3-dimethoxy[6]helicene (34). Density functional theory (DFT) calculations showed that bis[2-((1Z)-1-buten-3-ynyl)phenyl]acetylene (1) and isomeric [5]helicene (2) differ enormously in the Gibbs energy content (DeltaG = -136.6 kcal x mol(-1)) to favor highly the devised intramolecular simultaneous construction of three aromatic rings. 相似文献
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A series of N-[omega-[N-alkyl-N-(phenylmethyl)amino]alkyl]-3-arylpropenamides was prepared and tested for its inhibitory activities on acetylcholinesterase. Some in the series were found to be potent inhibitors. The structure-activity relationships were discussed in detail. 相似文献