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1.
Cíntia Salomão Pinto Zarth Andreas Koschella Annett Pfeifer Susann Dorn Thomas Heinze 《Cellulose (London, England)》2011,18(5):1315-1325
The homogeneous conversion of cellulose dissolved in N-methyl-2-pyrrolidone/LiCl and 1-N-butyl-3-methylimidazolium chloride with N-methyl-2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam, and N-methyl-2-piperidone in the presence of p-toluenesulphonic acid chloride was studied. Depending on the reaction conditions, novel cellulose esters with degree of substitution
(DS) values ranging from 0.12 to 1.17 could be prepared. The structure of the amino group containing cellulose esters was
elucidated by elemental analysis, FTIR- and NMR spectroscopy. NMR spectroscopy revealed an almost complete esterification
of position 6 of the anhydroglucose unit at DS of 1. The conversion can be conducted between room temperature and 40 °C, while
side-reactions became predominant at 60 °C. Starting with DS of 0.24, the samples were soluble both in water and dimethyl
sulphoxide. The derivatives described are capable of forming polyelectrolyte complexes. The samples were stable at room temperature
in aqueous solution at pH 2 and 7. Lower viscosities were found for samples with higher DS in aqueous solution at comparable
molar mass. 相似文献
2.
Synthesis, characterization and thermal properties of novel epoxy containing silicon and phosphorus nanocomposites by sol-gel method 总被引:3,自引:0,他引:3
Organic-inorganic hybrids were prepared using diglycidyl ether of bisphenol A (DGEBA) type epoxy and tetraethoxysilane via the sol-gel process. The DGEBA type epoxy was modified by a coupling agent to improve the compatibility of the organic and inorganic phases. The sol-gel technique was used successfully to incorporate silicon and phosphorus into the network of hybrids increasing flame retardance.Fourier transform infrared spectroscopy and 29Si nuclear magnetic resonance spectroscopy were used to characterize the structure of the hybrids. In condensed siloxane species for TEOS, silicon atoms through mono-, di-, tri-, and tetra-substituted siloxane bonds are designated as Q1, Q2, Q3, Q4, respectively. For 3-isocyanatopropyltriethoxysilane and diethylphosphatoethyltriethoxysilane, mono-, di-, tri-, tetra-substituted siloxane bonds are designated as T1, T2, T3. Results revealed that Q4, Q3, T3 are the major environments forming a network structure. The morphology of the ceramer was examined by scanning electron microscopy and Si mapping. Particle sizes were below 100 nm. The hybrids were nanocomposites. The char yield of pure epoxy resin was 14.8 wt.% and that of modified epoxy nanocomposite was 31 wt.% at 800 °C. A higher char yield enhances the flame retardance. Values of limiting oxygen index of pure epoxy and modified epoxy nanocomposites are 24 and 32, respectively, indicating that modified epoxy nanocomposites possess better flame retardance than the pure epoxy resin. 相似文献
3.
4.
Akhtaruzzaman M Kamata N Nishida J Ando S Tada H Tomura M Yamashita Y 《Chemical communications (Cambridge, England)》2005,(25):3183-3185
Dithiazolylbenzothiadiazoles easily obtained have high electron affinity and the FET device of a trifluoromethylphenyl derivative exhibited a good n-type performance with high electron mobility. 相似文献
5.
Ching Hsuan Lin Kai Zhi Yang Tsu Shang Leu Chun Hung Lin Jhao Wei Sie 《Journal of polymer science. Part A, Polymer chemistry》2006,44(11):3487-3502
We synthesized a novel epoxy (dopotep) and cyanate ester (dopotcy) based on a phosphorus‐containing triphenol (dopotriol). The proposed structures were confirmed by IR, mass spectra, NMR spectra, and epoxy‐equivalent‐weight titration. The synthesized dopotep or dopotcy was copolymerized with diglycidyl ether of bisphenol A (DGEBA), 6′,6‐bis(3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazineyl)methane (F‐a), or dicyanate ester of bisphenol A (BADCY). Thus, copolymers based on DGEBA/dopotep/diphenylmethane (ddm), F‐a/dopotep, BADCY/dopotcy, and DGEBA/dopotcy were developed. The thermal properties, dielectric properties, and flame retardancy of these copolymers were investigated. The curing kinetics of dopotep/ddm and dopotep/diamino diphenylsulfone were studied with differential scanning calorimetry. The microstructure of DGEBA/dopotcy was studied with IR. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3487–3502, 2006 相似文献
6.
This letter describes the first example of the synthesis of isocyanide derivatives of α-aminoalkylphosphonate diphenyl esters. This method produces the title compounds in high purity and in very good yields. It also permits the generation of an α-aminophosphonate-based library of biologically active phosphonopeptides. Preliminary experiments demonstrate their application as substrates for the Ugi-type multicomponent condensation. 相似文献
7.
In the work discussed in this paper, a series of novel benzaldehyde derivatives containing 1,3,4-thiadiazole were prepared in high yield from 4-fluorobenzaldehyde and 2-amino-5-substituted-1,3,4-thiadiazole. The products were characterized by determination of melting point, elemental analysis, and UV–visible, IR, 1H NMR, and 13C NMR spectroscopy. The fluorescence properties of the compounds were also studied by recording their fluorescence emission spectra. 相似文献
8.
Two novel nonaheteroacene derivatives: 24,27,30,33-tetra-tert-butyl-6,8,10,17,19,21-hexaaza-1.22,4.5,11.12,15.16-tetrabenzono-nonaacene (1) and 24,27,30,33-tetra-tert-butyl-6,10,17,21-tetraaza-8,19-benzodioxin-1.22,4.5,11.12,15.16-tetrabenzono-nonaacene (2), have been successfully synthesized through cyclocondensation reactions. The studies on UV–vis and cyclic voltammogram suggest that compound 1 has a smaller bandgap comparing to that of compound 2, indicating that oxygen atoms can destroy the conjugation in compound 2. The results are further confirmed by theoretical simulation. 相似文献
9.
A series of new pyrazolopyrimidine derivatives containing sulfur atom 5 has been designed and synthesized by treatment of carbodiimide 3 , which came from iminophosphorane 2 undergoing a aza‐Wittig reaction with phenyl ioscyanate, with alkylamine. The structures of compounds 5 were confirmed by 1H NMR, IR, EI‐mass spectroscopy, and elemental analysis. The results of preliminary bioassay indicate that most compounds 5 exhibit an inhibition effect against Cercospora beticola, Botryosphaeria berengeriana, and Pellicularia sasakii, and compound 5g shows 91.2% inhibitory rate to root of rape and the other less than 50% at 100 mg/l. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:333–337, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20024 相似文献
10.
N. V. Myagkova G. R. Rakhmonberdiev Z. G. Sagdieva A. S. Sidikov 《Chemistry of Natural Compounds》1997,33(1):76-79
The thermodynamics of the mixing of water-soluble mixed cellulose esters with water has been studied. A dependence of the affinity of a water-soluble cellulose acetate for water on the nature of a new radical introduced into the macromolecule and the competing interaction of molecules of the same and different types has been shown. Thermodynamic analysis has demonstrated the dominating role of solvation among the various factors determining the interaction of cellulose acetomaleate and acetophthalate with a solvent. A fall in affinity in the cellulose aminoacetate-water system is due to the contribution of entropy effects, leading to an increase in the Flory-Huggins parameter.Tashkent Institute of Chemical Technology. Translated from Khimiya Prirodnykh Soedinenii, Vol. 33, No. 1, pp. 97–101, January–February, 1997. 相似文献
11.
Rita Meyer Constance E.J. van Rensburg Helmar Görls 《Journal of organometallic chemistry》2005,690(1):117-125
The titanocene complexes [TiCp2(Cl)R] (1), [TiCp2(Cl)SR] (2), [TiCp2(SR)2] (3) with R = benzothienyl (BT) A and dibenzothienyl (DBT) B, were synthesized and the molecular structures of [TiCp2(Cl)DBT] (1B) and [TiCp2(Cl)SDBT] (2B) confirmed by single crystal X-ray diffraction studies. The dibenzothiophene rings are planar and for 1B in the plane of the titanium and chloro ligand. The chloro ligand is in a trans position to the sulfur atom with respect to the titanium-carbon bond. The complexes were studied for their electronic and structural features and preliminary tests were conducted for their tumor inhibiting properties against HeLa and COLO 320M tumor cell lines. These antitumor activities were compared against those observed for titanocene dichloride (S-01) under similar conditions and the highest antitumor activity was recorded for 2B. 相似文献
12.
Qing-He Liu Jin Yang Ji-Cheng Ma Wei-Li Li Xue Wang 《Journal of Molecular Structure》2010,963(1):41-44
Peripherally tetraimido-substituted phthalocyaninato zinc compounds 1-3 were synthesized through the reaction of tetraamino-substituted phthalocyaninato zinc with 4-Br-1,8-naphthalic anhydride, 4-hexahydropyridine-1,8-naphthalic anhydride and 4-morpholine-1,8-naphthalic anhydride, respectively. The compounds were characterized by MS, 1H NMR, UV-vis, IR and elemental analysis, the results of which were consistent with the proposed structures. The effects of substitutes, acid/base and solvents on the UV-vis spectra of the new complexes were discussed in detail. 相似文献
13.
The novel benzoxazine monomer containing phosphorus has been synthesized based on multifunctional amine route from bis(4-aminophenyl)phenylphosphate,p-cresol and formaldehyde.Subsequently,the benzoxazine monomer was thermo-cured into polybenzoxazine containing phosphorus.The chemical structures were identified by nuclear magnetic resonance(NMR),Fourier transform infrared spectroscopy(FT-IR).The curing reaction was monitored by differential scanning calorimetry(DSC) and FT-IR.The thermal and flame-retardant properties of obtained polybenzoxazine were evaluated by dynamic mechanical thermal analysis(DMA),thermal gravimetric analysis(TGA) and oxygen index meter, respectively.The results show that the novel polybenzoxazine has high limiting oxygen index(38.1) and glass transition temperature(232℃). 相似文献
14.
Isabel S. Gonçalves Cláudia C.L. Pereira Alan Hazell 《Journal of organometallic chemistry》2007,692(7):1593-1600
Reaction of NaBH4 with [IndCpMo(dppe)](BF4)2 (1) in acetone yields [IndMo(η4-C5H6)(dppe)]BF4 (2) quantitatively. The hydride addition takes place at the external face of the Cp ring. Dissolution of 2 in dichloromethane gives [IndMo(η4-C5H5-exo-CH2Cl)(dppe)]BF4, as confirmed by elemental analysis, IR and 1H NMR spectroscopy. The similar dication [IndCpMo{P(OMe)3}2](BF4)2 (4) reacts with NaBH4, in a solvent dependent manner. In acetonitrile, [IndMo(η4-C5H6){P(OMe)3}2]BF4 (5) is obtained and in acetone a P(OMe)3 ligand is lost resulting in the asymmetric phosphite-hydride, [IndCpMoH{P(OMe)3}]+ (6). The molecular structures of [IndMo(η4-C5H6){P(OMe)3}2]PF6 and [IndCpMoH{P(OMe)3}]PF6 were characterized by single-crystal X-ray diffraction. 相似文献
15.
Chin‐Lung Chiang Chen‐Chi M. Ma 《Journal of polymer science. Part A, Polymer chemistry》2003,41(9):1371-1379
Novel ladderlike polysilsesquioxanes that contain phosphorus were successfully synthesized by the sol–gel method. The polysilsesquioxanes were characterized by Fourier transform infrared spectroscopy, 29Si NMR, and X‐ray diffraction. The characterizations demonstrated that the polymer possesses a typical ladderlike structure. The thermogravimetric and differential scanning calorimetric data revealed that the polysilsesquioxanes possess excellent thermal stability. A kinetic analysis of thermal degradation showed that the activation energy of thermal degradation is 187 kJ/mol, according to Kissinger's method. The activation energy of thermal degradation normally increases with conversion (from 171 to 309 kJ/mol) according to Ozawa's method. The average activation energy, calculated by Ozawa's method, was 209 kJ/mol. The scanning electron microscopic photograph and Si and P mappings of ladderlike polysilsesquioxanes showed that the particles were uniformly dispersed at the molecular level and that the sizes of the polysilsesquioxane particles were less than 100 nm. The ultraviolet–visible spectra of the ladderlike polysilsesquioxanes revealed no absorbance in the range of 400–800 nm. Ladderlike polysilsesquioxanes possess excellent optical transparency and excellent flame retardance. This transmittance may be used as a criterion for identifying the formation of a homogeneous phase. These polymers have great potential in waveguide applications. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1371–1379, 2003 相似文献
16.
Guohua Ding Zhaowu Xu Gaoyu Zhong Shuping Jing Fuyou Li Weihong Zhu 《Research on Chemical Intermediates》2008,34(2-3):299-308
A series of naphthalimide derivatives containing a benzoazole unit (benzothiazole, benzoxazole or benzimidazole) as electron-transporting unit was designed and synthesized, and their photophysical and electroluminescent properties were investigated. The key design of molecular structures included the use of carrier-transporting fragments, together with twisted molecular conformation that could eliminate the recrystallization tendency and favour the formation of a stable amorphous state. ITO/NPB/emissive layer/Mg∶Ag/Ag bilayer electroluminescent devices were fabricated. Green or yellow-green electroluminescence was obtained successfully with peak emission in the range 530–560 nm. 相似文献
17.
K. Kishore P. Kannan K. Iyanar 《Journal of polymer science. Part A, Polymer chemistry》1991,29(7):1039-1044
Polyphosphate esters containing ferrocene structures were synthesized from 1,1′-bis (p-hydroxyphenylamido) ferrocene and 1,1′-bis (p-hydroxyphenoxycarbonyl) ferrocene with aryl phosphorodichloridates by interfacial polycondensation using a phase transfer catalyst. The polymers were characterized by infrared, 1H-, 13C-, and 31-NMR spectroscopy. The molecular weights were determined by end group analysis using 31P-NMR spectral data. The thermal stability and fire retardancy were respectively determined by thermogravimetry and limiting oxygen index (LOI) measurements. The polyamide-phosphate esters showed better thermal stability and higher LOI values than the polyester-phosphate esters. 相似文献
18.
A series of bisthienylethenes containing imidazole and imidazolium derivatives have been prepared and the products have been characterized by means of NMR and MS.Their photochromic and fluorescent switch properties have been investigated by UV–vis absorption spectra and fluorescence spectra.The fluorescent emissions of these kinds of photochromic compounds can be simply modulated by varying the imidazole groups,which shows that these compounds may have potential application in the design of fluorescent photochromic materials. 相似文献
19.
Synthesis and characterization of ferrocene‐containing main‐chain polyamides are reported in this article. A new, interesting type of organometallic monomer (FDADO) based on ferrocene was prepared by interfacial condensation of 1,1′‐dichlorocarbonyl ferrocene with 2 mol 1,8‐diamino‐3,6‐dioxaoctane (DADO). A series of ferrocene‐based polyamides was prepared via polycondensation of the ferrocenyl diamine (FDADO) with different diacid chlorides using two different methods. The monomer and polymers were characterized by elemental analysis, infrared and NMR spectroscopy. The thermal stability and behavior of the synthesized polymers were evaluated by thermal gravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC). The crystallinity of polymers was examined by X‐ray diffraction analysis. Inherent viscosity, solubility and flame‐retardancy of the polymers were also studied. The obtained polymers showed good heat‐resistance and flame‐retardancy, and improved solubility vs generally reported polyamides in some common organic solvents. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献