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1.
Devendra Kumar 《Journal of polymer science. Part A, Polymer chemistry》1984,22(11):3439-3446
Three new thermally stable polypyromellitimide films were made by the thermal cyclodehydration of the corresponding polyamic acids obtained by the polymerization of pyromellitic dianhydride with 4,4′-bis{N2-[4-(4-aminobenzyl)phenyl]aspartimido} diphenylmethane, 4,4′-bis{N2-[4-(4-aminophenoxy)phenyl]aspartimido} diphenylether, and bis(4-aminophenoxy)tetrakis (4-phthalamic acid phenoxy)cyclotriphosphazene. The bis(4-aminophenoxy)tetrakis (4-phthalamic acid phenoxy)cyclotriphosphazene was obtained from hexakis(4-aminophenoxy)cyclotriphosphazene involving its reaction with phthalic anhydride. The structure of these materials and precursors were characterized by using Fourier-transform-infrared (FT–IR) and proton nuclear magnetic resonance spectroscopy. The thermal stabilities of the films were evaluated by the thermogravimetric analysis, showing char yields at 800°C ranging from 68% to 58% in a nitrogen atmosphere and 24% in air atmosphere. 相似文献
2.
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
3.
Qianqian BuShujiang Zhang Hui LiYanfeng Li Chenliang GongFengchun Yang 《Polymer Degradation and Stability》2011,96(10):1911-1918
A novel method for the preparation of an asymmetric fluorinated aromatic diamine, 3,4′-bis(4-amino-2-trifluoromethylphenoxy)-benzophenone was investigated. This new diamine containing trifluoromethyl side group was synthesized from the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride and 3,4′-dihydroxybenzo phenone in the presence of potassium carbonate, followed by catalytic reduction with SnCl2·6H2O and concentrated hydrochloric acid. This novel diamine was used to react with different commercially available aromatic tetracarboxylic dianhydrides to prepare polyimides via thermal or chemical imidization. The polyimide properties such as inherent viscosity, solubility, thermal and surface properties were investigated to illustrate the contribution of the trifluoromethyl group and the asymmetry structure of the polyimide. The polyimides obtained had good thermal stability and the glass transition temperature values ranged from 225 to 267 °C. All of these novel polyimides held 10% weight loss at the temperature above 543 °C in air and left more than 47% residue even at 800 °C in nitrogen. The inherent viscosities of the obtained polyimides were above 0.73 dL/g and were easily dissolved in both polar, aprotic solvents and some low-boiling-point solvents. Moreover, these PI films had dielectric constants of 2.94-3.53 (1 kHz), with moisture absorption in the range of 0.07-0.34 wt%. In comparison of the PIs (5) series with the analogous symmetric PIs (6) series based on 4,4′-bis(4-amino-2-trifluoromethylphenoxy)-benzophenone, the (5) series revealed better solubility, low dielectric constant and moisture absorption. 相似文献
4.
New polyazomethines have been synthesized based on polynuclear dihydroxy quinones (5,8-dihydroxy-1,4-naphthoquinone and 1,4-dihydroxyanthraquinone) and siloxane diamines differing by the siloxane sequence length (1,3-bis(3-aminopropyl)tetramethyldisiloxane and α,ω-bis(3-aminopropyl)oligodimethylsiloxane having about 12 siloxane units/sequence). The structures were verified by spectral analyses. Solubility tests, GPC and viscosity measurements were performed. Some properties of the resulted polymers were investigated by thermal (TGA and DSC), electrical, spectral (UV-Vis) and electrochemical (differential pulse voltammetry) methods. 相似文献
5.
A. Rodríguez-Galn J. J. Bou S. Muoz-Guerra 《Journal of polymer science. Part A, Polymer chemistry》1992,30(5):713-721
Stereoregular polyamides containing two chiral backbone carbons in the repeating unit were prepared by polycondensation of bis(pentachlorophenyl) 2,3-O-methylene-L -tartrate with 1,9 and 1,12-alcanediamines activated as N,N′-bis(trimethylsilyl) derivatives. The polymers were characterized by elemental analysis, IR, and 1H-NMR spectroscopy, and differential scanning calorimetry. Both viscosimetry and GPC were used to estimate the molecular weights which ranged between 6000 and 44000. These polytartaramides were readily soluble in chloroform, displayed moderate optical activity in solution, and formed highly crystalline films. 相似文献
6.
Synthesis of benzylidene-pendant polyphthalimidines from flexible bisphthalides and various diamines
Yoshio Imai Takeyoshi Takahashi Renzhi Nan Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》1983,21(5):1241-1249
New polyphthalimidine-forming monomers, 5,5′-(oxydi-p-phenylenedicarbonyl)bis(3-benzylidenephthalide) and the 6,6′-derivative, were synthesized by the Friedel–Crafts reaction of diphenyl ether with 5- and 6-chloroformyl-3-benzylidenephthalide, respectively. The direct polycondensation of these bisphthalides with both aliphatic and aromatic diamines in o-phenylphenol at 200–250°C afforded polyphthalimidines having inherent viscosities of 0.2–1.2 dL/g in almost quantitative yields. Syntheses of aliphatic polyphthalimidines with higher inherent viscosities were also achieved by a two-step procedure involving ring-opening polyaddition and subsequent thermal cyclodehydration. All the polymers were amorphous and readily soluble in N-methyl-2-pyrrolidone (NMP), m-cresol, nitrobenzene, pyridine, and chloroform. Tough and flexible films could be cast from NMP solutions of the polymers. Glass transition temperatures of the polyphthalimidines were in the range of 158–246°C. The thermogravimetry of the aromatic polymers showed 10% weight loss in air and nitrogen at 445–515 and 500–520°C, respectively. The crosslinking reaction of some benzylidenependant polyphthalimidines took place at 300°C through double-bond addition to afford cured polymers with improved thermal stability. 相似文献
7.
Lin Cheng Xi Gao Jian Shi Zhen Mao 《Journal of polymer science. Part A, Polymer chemistry》2002,40(20):3489-3496
Two unsymmetrical and kink non‐coplanar heterocyclic diamines, 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)phenyl](2H)phthalazin‐1‐one and 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐3,5‐dimethylphenyl](2H) phthalazin‐1‐one, were successfully synthesized by readily available heterocyclic bisphenol‐like monomers through two steps in high yields. A series of novel poly(arylene ether amides)s containing the phthalazinone moiety with inherent viscosities of 1.16–1.67 dL/g were prepared by the direct polymerization of novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. The polymers were readily soluble in a variety of solvents such as N,N‐dimethylformamide, N,N‐dimethylacctamide, dimethyl sulfoxide, N‐methyl‐2‐pyrrolidone, and even in pyridine, chloroform and m‐cresol. The glass‐transition temperatures were in the range of 291–329 °C, and the temperatures for 5% weight loss in nitrogen were above 490 °C. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3489–3496, 2002 相似文献
8.
Matthias Tacke Lorcan T. Allen William M. Gallagher Oscar Mendoza Franz-Josef K. Rehmann 《Journal of organometallic chemistry》2004,689(13):2242-2249
Starting from 6-(p−N,N-dimethylanilinyl)fulvene (1a) or 6-(pentamethylphenyl)fulvene (1b) [1,2-di(cyclopentadienyl)-1,2-di(p−N,N-dimethylaminophenyl)ethanediyl] titanium dichloride (2a) and [1,2-di(cyclopentadienyl)-1,2-bis(pentamethylphenyl)ethanediyl] titanium dichloride (2b) and their corresponding dithiocyanato complexes (3a, 3b) were synthesized. Titanocene 2b did not show a cytotoxic effect, but when 2a was tested against pig kidney carcinoma cells (LLC-PK) or human ovarian carcinoma cells (A2780/cp70) inhibitory concentrations (IC50) of 2.7 × 10−4 and 1.9 × 10−4 M, respectively, were observed. 相似文献
9.
J. G. Liu M. H. He H. W. Zhou Z. G. Qian F. S. Wang S. Y. Yang 《Journal of polymer science. Part A, Polymer chemistry》2002,40(1):110-119
Organosoluble polyimides were synthesized with the alicyclic dianhydride 1,8‐dimethylbicyclo[2,2,2]oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride and aromatic diamines. The polyimides possessed good solubility both in strong dipolar solvents and in common solvents; the thermal decomposition temperature of the polyimides exceeded 420 °C. Strong and flexible films of the polyimides, with the cutoff of ultraviolet–visible absorption lower than 310–320 nm, exhibited good features as the alignment layers for nematic liquid crystals with pretilt angles of 1.5–2.9°. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 110–119, 2002 相似文献
10.
Yoshio Imai Mitsuru Ueda Takeyoshi Takahashi 《Journal of polymer science. Part A, Polymer chemistry》1976,14(10):2391-2397
Aromatic and aliphatic polybenzodipyrrolediones have been synthesized directly by the solution cyclopolycondensation of two dibenzylidenebenzodifurandiones with four different diamines in refluxing m-cresol or o-phenylphenol in the presence of boric acid. The polymerizations proceeded smoothly in a homogeneous solution and afforded the heterocyclic polymers having inherent viscosities as high as 1.0 almost quantitatively. All the polymers were readily soluble in a wide range of solvents, including N-methyl-2-pyrrolidone (NMP), hot m-cresol, and hot pyridine. Tough, transparent, yellow films could be cast from NMP solutions of the polymers. Thermogravimetric analysis of the aromatic polybenzodipyrrolediones showed a 10% weight loss temperature of 460–500°C under nitrogen. The results also indicated that the aromatic polymers were somewhat less thermally stable than wholly aromatic polypyromellitimides. 相似文献
11.
Yu. N. Lazareva M. N. Vidyakin A. Yu. Alentiev M. Yu. Yablokova A. A. Kuznetsov I. A. Ronova 《Polymer Science Series A》2009,51(10):1068-1074
Gas-separating membrane characteristics of polyimide films composed of the common fragment of benzophenone-3,3′,4,4′-tetracarboxylic
dianhydride and diamines of varying structure were studied. Permeability coefficient P, diffusion coefficient D, and solubility coefficient S for H2, CO, CO2, and CH4 were determined. The polyimide derived from m-phenylenediamine exhibited the best gas-separating properties. A relationship between the chain rigidity, free volume, and
transport parameters (P, D, S, and selectivity) of polyimide was established on the basis of the data. It was shown that there is an optimal chain rigidity
for the studied polyimides that results in polymer structurization during film preparation and corresponds to high separation
selectivity. 相似文献
12.
Two kinds of aromatic, unsymmetrical diamines with ether-ketone group, 3-amino-4′-(4-amino-2-trifluoromethylphenoxy)-benzophenone and 4-amino-4′-(4-amino-2-trifluoromethylphenoxy)-benzophenone, were successfully synthesized with two different synthetic routes. Then, they were polymerized with 4,4′-oxydiphthalic anhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, and 2,2′-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride to form a series of fluorinated polyimides via a conventional two-step thermal or chemical imidization method. The resulting polyimides were characterized by measuring their solubility, viscosity, mechanical properties, IR-FT, and thermal analysis. The results showed that the polyimides had inherent viscosities of 0.48-0.68 dl/g and were easily dissolved in bipolarity solvents and common, low-boiling point solvents. Meanwhile, the resulting strong and flexible polyimide films exhibited excellent thermal stability, e.g., decomposition temperatures (at 10% weight loss) are above 575 °C and glass-transition temperatures in the range of 218-242 °C. The polymer films also showed outstanding mechanical properties, such as tensile strengths of 86.5-132.8 MPa, elongations at break of 8-14%, and initial moduli of 1.32-1.97 GPa. These outstanding combined features ensure that the polymers are desirable candidate materials for advanced applications. 相似文献
13.
《Journal of Coordination Chemistry》2012,65(1):156-162
Some neutral tetradentate N2O2 type complexes of Co(II) have been synthesized using Schiff bases formed by condensation of 5-nitro-salicylaldehyde with various diamines in alcohol. The nature of the ligands and complexes was established by spectroscopic techniques. The Schiff bases are bivalent anions with tetradentate ONNO donors derived from phenolic oxygen and azomethine nitrogen. IR and UV-Vis spectral data suggest that all the complexes are square-planar. 相似文献
14.
Keisuke Kurita Hiroshi Itoh Yoshio Iwakura 《Journal of polymer science. Part A, Polymer chemistry》1979,17(4):1187-1198
Compounds in the N-methylolimide group reacted smoothly with amines in the presence of water to yield the corresponding condensation products. Polycondensations of bismethylolimides, N,N′-bismethylolpyromellitic diimide, and N,N′-bismethylolbenzophenonetetracarboxylic diimide, with amines such as aromatic diamines, piperazine, and n-butylamine, were carried out in DMAc that contained 1% water to produce linear polyamine-imides. The polyamine-imides assumed various colors, from very pale yellow to deep purple, and had inherent viscosities in the 0.07–0.37-dl/g range. Most of these polymers were soluble in polar solvents such as DMAc and DMSO. The thermal stability of the polymers was examined by thermogravimetric analysis; decomposition started at 210–350°C and weight residue at 500°C was 22–85% in air. 相似文献
15.
Alan R. Katritzky Roland T. Langthorne Ranjan C. Patel Gerard Lhommet 《Tetrahedron》1981,37(13):2383-2390
Pyridiniums derived from amino alcohols cyclise to ethers or rearrange to aldehydes on heating. Monopyridiniums from diamines can be acylated or converted into ureas or thioureas: these products cyclise on heating in solution to give dihydro-thiazoles, -4H-thiazines, -oxazoles, -4H-oxazines, or tetrahydro-3H-thiazepines. 相似文献
16.
Ana Paula M. Alves André Leonardo P. Silva Oberto G. da Silva Maria G. da Fonseca Luiza N. H. Arakaki J. G. P. Espínola 《Journal of Thermal Analysis and Calorimetry》2007,87(3):771-774
Silylation of vermiculite surface with organosilane (H3CO)3SiR,
being R is the corresponding organic moieties
–CH2CH2CH2Cl,
were carried out to yield organofunctionalized nanomaterial, named as VCl.
The product reacted subsequently with three aliphatic diamines H2N
(CH2)nNH2
(n=2, 4 and 6). The new hybrids were characterized
by elemental analysis, infrared spectroscopy, X-ray diffraction and thermogravimetry.
The grafting chloro derivates onto surface amounted to 2.1 mmol g–1.
The incorporation of alkyl amines was more effective for butyl>ethylene>hexyldiamines.
The sequence is in agreement with thermogravimetry and elemental analysis
data. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(18):2884-2895
New macrocyclic complexes were synthesized by template reaction of 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane, 1,4-bis(2-carboxyaldehydephenoxy)butane or 1,3-bis(2-carboxyaldehydephenoxy)propane with 1,4-bis(2-aminophenoxy)butane, 1,3-bis(2-aminophenoxy)butane, 1,4-bis(4-chloro-2-aminophenoxy)butane or 1,3-bis(4-chloro-2-aminophenoxy)butane and Cu(NO3)2 ·?3H2O or Cu(ClO4)2 ·?6H2O, respectively. The complexes have been characterized by elemental analysis, IR, 1H and 13C NMR, UV–Vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. All complexes are diamagnetic and binuclear. 相似文献
18.
19.
Two diamines were synthesized as new aromatic monomers. A series of novel aromatic polyamides (aramids) were also synthesized by direct and indirect polycondensation of these diamines with various aromatic dicarboxylic acids. These aramids have inherent viscosities of 0.43-0.84 dl/g and were obtained in quantitative yield. 相似文献
20.
Shou-Ri Sheng Xue-Liang Pei Zhen-Zhong Huang Xiao-Ling Liu Cai-Sheng Song 《European Polymer Journal》2009,45(1):230-236
A series of novel fluorinated aromatic polyamides derived from a new monomer, 2-(4-trifluoromethylphenoxy)terephthaloyl chloride (TFTPC), with various aromatic diamines were synthesized and characterized. The polyamides were obtained in high yields and moderately high inherent viscosities ranging from 1.07 to 1.16 dL/g. All the polyamides were amorphous and readily soluble in many organic solvents, such as N-methyl-2-pyrrolidinone (NMP), N,N′-dimethylacetamide (DMAc), N,N′-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and could afford flexible and tough films via solution casting. The cast films exhibited good mechanical properties with tensile strengths of 82.8-107.3 MPa, elongation at break of 4.1-7.2%, and tensile modulus of 2.26-3.95 GPa. These polyamide films also exhibited good thermal stability with the glass transition temperature of 222-294 °C, the temperature at 5% weight loss of 442-472 °C in nitrogen. They exhibited low dielectric constants ranging from 3.25 to 3.39 (1 MHz), low moisture absorption in the range of 1.32-2.45%, high transparency with an ultraviolet-visible absorption cut-off wavelength in the 330-371 nm range, and excellent electrical properties. 相似文献