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Metal phthalocyanine oligomers that possess peripheral carboxylic acid groups were prepared by the reaction of pyromellitic dianhydride, a metal salt, urea, and a catalyst. These materials have blue to purple colors with a metallic luster and are soluble in sulfuric acid, dimethylsulfoxide, dimethylformamide, and dimethylacetamide. Their thermal stability is high in an anaerobic atmosphere with char yields of 80–85% at 800°C. Elemental, spectral, and titrimetric analyses and thermal studies were carried out to characterize them.  相似文献   

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In this paper, we introduce a novel high-performance polymer, poly(imino imino ether ether ketone ketone), which has been synthesized by the palladium-catalyzed C-N cross coupling reaction of 1,4-bis-(4-bromobenzoyl) benzene and 1,3-bis-(4-aminophenoxy) benzene. The structure of the polymer is characterized by means of 1H NMR spectroscopy and elemental analysis, and the results show a good agreement with the proposed structure. Compared with traditional poly(ether ether ketone)s, the solubility of the synthesized polymer in common organic solvents was higher; it also exhibited high glass transition temperature (T g = 176°C) and good thermal stability with high decomposition temperature (T 5 = 400°C).  相似文献   

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Poly(dimethylsilylene) higher polymers prepared by alkali metal coupling of purified dimethyldichlorosilane were found to be high melting, largely crystalline polymers, soluble in solvents at temperatures above 200°C.  相似文献   

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Poly(p-phenylene sulfide) (PPS) is a melt- and solution-processible polymer which on treatment with AsF5 forms a blue-black material with a conductivity of 1–10 Ω?1 cm?1. Thermopower measurements indicate that the resulting polymer is p type, consistent with partial oxidation of the PPS by the AsF5. The rate and extent of this doping process prove to be particularly sensitive to the degree of crystallinity of the starting polymer. There is also evidence of crosslinking of the polymer chains during the reaction with AsF5. The details of both the chemistry and physics of the doping of PPS and several of its derivatives are presented.  相似文献   

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Poly(organophosphazenes)--unusual new high polymers.   总被引:5,自引:0,他引:5  
An inorganic-backbone high polymer system based on alternating phosphorus and nitrogen atoms promises to solve many of the problems hitherto associated with conventional organic polymers. The chemistry, structure, biomedical, and technological aspects of these polymers are reviewed.  相似文献   

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Bergbreiter DE  Li C 《Organic letters》2003,5(14):2445-2447
[reaction: see text] Use of soluble poly(4-tert-butylstyrene) (PtBS) as a support in synthesis is demonstrated. These soluble polymers supported catalysts that were used in a monophasic medium. Subsequent separation of the catalysts after reaction was effected either by cooling- or by water-induced liquid/liquid-phase separation. Specific catalysts studied included both phosphine and DMAP nucleophilic catalysts. Low loadings of an azo dye quantified the efficiency of separation and recovery of these catalysts through multiple reaction cycles.  相似文献   

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New poly(metal phthalocyanine) pyromellitimides of copper, cobalt, nickel, and zinc were synthesized and elemental, IR, TGA, and inherent viscosity measurement studies were done to characterize these polymers. They showed exceptional thermal and thermo-oxidative stability with char yields at 800°C ranging from 75 to 87% in a nitrogen atmosphere. The ratio of the polymer decomposition temperatures in air and nitrogen (PDT) (air)/PDT (N2) varied from 0.91 to 0.97, which indicated that the onset of degradation of these polymers is greatly affected by the presence of an oxidizing atmosphere. Isothermal studies were done to evaluate the long-term thermal stability of these polymers.  相似文献   

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The in situ polymerization of 1,1,3,3-tetraphenyl-1,3-disilacyclobutane with or without a catalyst in flexible organo-silicon polymers was demonstrated to provide poly(silmethylene)-based polymer blends. An alternative route, which implies preparation of blends via synthesis of a flexible polymer in the presence of a rigid polymer, was also promising. The resulting polymer blends were characterized by DSC, dynamic mechanical analysis, and solvent extraction. No chemical interaction is observed between component polymers of blends prepared by the in situ bulk polymerization method while formation of block or graft copolymers comprising poly(diphenylsilmethylene) and flexible polymers is suggested when in situ copper-catalyzed polymerization was employed. A morphological difference between samples synthesized by the different methods was suggested by microscopic observation. © 1997 John Wiley & Sons, Inc.  相似文献   

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Two coordination polymers, namely [Ni(L1)-(ndc)(H2O)] n (1) and [Cu(L2)0.5(ndc)] n (2) (L1 = 1,3-bis(2-methylbenzimidazol-1-ylmethyl)benzene, L2 = 1,4-bis(2-methylbenzimidazole)butane, H2ndc = 2,6-naphthalenedicarboxylic acid) have been synthesized and characterized by single-crystal and powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and elemental analysis. Complex 1 features a 2D 3-connected hcb network with 63 topology, which is further extended into a 3D supramolecular framework by O–H···O hydrogen bonding interactions. Complex 2 possesses a 3D threefold interpenetrating (4,5)-connected xah topological network, and its Schläfli symbol is (42.62.82)(46.64). Both complexes exhibit intense luminescence emissions in the solid state and promising catalytic activities for the degradation of Congo red azo dye in a Fenton-like process.  相似文献   

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Crystalline poly(n-nonaldehyde) (PNA) was prepared by anionic polymerization of n-nonaldehyde (NA) in methylcyclohexane (MCH) with lithium tertiary butoxide (LTB) as the initiator. Normal low-temperature conditions did not give polymer reprodusibly; however, when the polymerization was carried out with a gradual temperature decrease to ?60°C holding at this temperature followed by completion at ?78°C, a moderate yield of PNA was obtained. The polymer was acetate capped and characterized. Infrared and PMR spectroscopy, as well as degradation of the polymer in the presence of 2,4-dinitrophenylhydrazine to the hydrazone, conclusively proved the chemical structure of the polymer. VPO measurements and measurement of the inherent viscosity showed the polymer to be of moderate molecular weight. PNA is highly crystalline and shows two transition regions, one corresponding to the melting of the main chain at temperatures above 120°C and one region between 50 and 80°C, which is related to the crystallization of the aliphatic side chains. PNA, although inherently brittle, can be extruded through an orifice at a temperature near the side-chain melting temperature to give an extrudate whose x-ray patterns show the characteristics of a fiber diagram. It is suggested that the crystal structure of the PNA is similar to that of poly(n-heptaldehyde) but with a larger a spacing, which is expected from a longer aliphatic side chain.  相似文献   

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Polydimethylsilylene is a largely crystalline, high-melting polymer that is soluble only above 200°C and does not thermoform below its decomposition temperature. Introduction of ethyl and propyl substituents into the linear silylene system by random copolymerization of dimethylsilylene with ethylmethyl- and methylpropylsilylenes leads to tractable polymers that are soluble in common solvents at normal ambient temperatures.  相似文献   

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A series of polymers, {Cr(OH)(OPRR′O)[OOC(CF2)nCF(CF3)2]}x has been prepared and studied. The polymers with R = R′ = C6H5 are soluble in CCl2FCClF2, whereas those with R = CH3 and R′ = C6H5 and with R = R′ = C8H17 are insoluble in all solvents. Attempts to prepare similar materials without hydroxyl groups gave the polymers {Cr(OH)r(OPRR′O)p[OOC(CF2)nCF(CF3)2]q}x with 0 < r < 1. The latter polymers are much more tractable than the former; however they are also less thermally stable. The perfluoro-carboxylate groups in these materials can either be chelating or bridging, depending on the other ligands present.  相似文献   

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Poly(metal phthalocyanine)imides of copper, cobalt, nickel, and zinc were synthesized by the reaction of metal phthalocyanino tetramines with benzophenone tetracarboxylic dianhydride. These polymers were characterized by elemental analyses and IR, TGA, and inherent viscosity studies. Noteworthy features of these phthalocyanine polymers are their remarkable thermal and thermooxidative stabilities with char yields at 800°C that range from 78 to 83% in a nitrogen atmosphere. The relative thermal stabilities of these polymers have been evaluated by activation energy measurements.  相似文献   

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A new monomer, 1,8-diaminocarbazole (DACz), has been synthesized as a missing link between two classes of electropolymerizable compounds – aromatic amines and carbazoles to combine some attractive features of both. Electropolymerization of DACz on Pt substrate carried out by cyclic voltammetry from acetonitrile and aqueous (neutral and acidic) solutions leads to formation of compact and very well adherent conducting films, electroactive in both media. In aqueous solutions poly(1,8-diaminocarbazole) (PDACz) exhibits a linear dependence of redox potential on pH. Morphology of the polymer films was studied by AFM using a tapping mode. Ability of amino groups of PDACz for post-functionalization was studied by covalent bonding of tyrosinase.  相似文献   

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