Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

Study of Model Copper-Based Catalysts by Simultaneous Differential Scanning Calorimetry, X-Ray Diffraction and Mass Spectrometry

1987 ◽  
Vol 111 ◽  
Author(s):  
Robert A. Newman ◽  
Joseph A. Blazy ◽  
Timothy G. Fawcett ◽  
Larry F. Whiting ◽  
Robert A. Stowe
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Copper Oxide ◽  
Cuprous Oxide ◽  
Copper Surface ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Simultaneous Generation ◽  
X Ray

AbstractRecently, a new materials characterization instrument and technique employing simultaneous differential scanning calorimetry/X-ray diffraction/mass spectrometry (DSC/XRD/MS) have been developed at Dow. Use of this technology can be illlustrated by the study of various materials such as polymers, organics/pharmaceuticals, inorganics, and catalysts.Presented here is the use of the DSC/XRD/MS instrument to study the thermostructural behavior of four model copper-based catalyst systems during activation and regeneration. The instrument allows simultaneous generation of thermal, structural and chemical data in real-time during temperature programmed analysis and provides useful insights into the chemical and physical processes occurring. In addition, the calorimetry data yield qualititative information on the magnitude and rate of heat flow, while the diffraction data provide structural dynamics of reduction, oxidation and crystallite growth.The results of this study conclusively show cuprous oxide as an intermediate in the reduction of the copper oxide portion of each of the model catalysts. However, such features as the onset temperature and copper surface area varied widely among the four catalysts in response to the same chemical event conducted under similar experimental conditions. On the other hand, oxidation runs on the reduced catalysts were all similar to each other, first producing cuprous oxide from copper metal over a broad range of temperature, followed by the oxidation of cuprous oxide to copper oxide at even higher temperatures.

scholarly journals Solvate Formation of Bis(demethoxy)curcumin: Screening and Characterization

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 407 ◽  
Author(s):  
Lina Yuan ◽  
Heike Lorenz
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Mass Loss ◽  
Storage Conditions ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
X Ray ◽  
Ambient Storage

Solvate formation of bis(demethoxy)curcumin (BDMC) was screened. Six solvates were obtained out of the nineteen solvents investigated. In the present work, three solvates, i.e., BDMC-tetrahydrofuran (THF), BDMC-1,4-dioxane (DIO) and BDMC-dimethyl sulfoxide (DMSO), were thoroughly studied. Their desolvation processes were characterized by temperature-resolved powder X-ray diffraction (TR-PXRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and hot-stage microscopy (HSM). TR-PXRD shows that all the solvates desolvate as the mother BDMC form and no new polymorph could be obtained. The stoichiometric ratio of solvates was calculated via the mass loss of solvents determined by TGA. The thermal stabilities of the solvates were obtained from DSC data and followed the order: BDMC-DMSO > -THF > -DIO. Moreover, stability performances at ambient storage conditions recorded by PXRD show that BDMC-DMSO was stable over three months.

scholarly journals Original Macromolecular Architectures Based on poly(ε-caprolactone) and poly(ε-thiocaprolactone) Grafted onto Chitosan Backbone

2018 ◽  
Vol 19 (12) ◽  
pp. 3799 ◽  
Author(s):  
Cüneyt Ünlü ◽  
Eric Pollet ◽  
Luc Avérous
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Hexamethylene Diisocyanate ◽  
Proton Nuclear Magnetic Resonance ◽  
High Yield ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Molar Ratios ◽  
Grafting Onto

Polyester and/or polythioester grafted chitosan copolymers were synthesized. For that, poly(ε-caprolactone) (PCL), poly(ε-thiocaprolactone) (PTCL), and their copolymers were first synthesized by ring opening polymerization. Copolymers with caprolactone:thiocaprolactone (CL:TCL) molar ratios of 2:1, 1:1, 1:2 were synthesized. All of the synthesized macromolecular architectures were characterized using different spectral (Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H-NMR), X-Ray diffraction (XRD)) and thermal (Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA)) methods. Grafting was then performed according two distinct routes: (i) using a blend of both homopolymers (PCL and PTCL) or (ii) using pre-synthesized copolymers with controlled CL:TCL ratios. Hexamethylene diisocyanate was used as a grafting/coupling agent through urethane bonds with high yield. Grafting preferentially occurred at sulfur sites. The results indicated that PTCL is more reactive and favorable than PCL for grafting onto chitosan. With the homopolymers blend grafting route, the corresponding materials mostly had a higher PTCL portion than expected. To obtain polyester grafted chitosan with a determined CL:TCL ratio, the copolymer grafting route would yield better results.

Synthesis and properties of polyimides from 1,4-bis(4-amino-2-phenylphenoxy) benzene and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl

2012 ◽  
Vol 24 (8) ◽  
pp. 783-792 ◽  
Author(s):  
Atsushi Morikawa ◽  
Fumi Miyata ◽  
Jun Nishimura
Keyword(s):  
Ring Opening ◽  
Mechanical Analysis ◽  
Ring Opening Polymerization ◽  
Dielectric Constants ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Property Relationships ◽  
Step Procedure

Diamines, namely, 1,4-bis(4-amino-2-phenylphenoxy) benzene (1) and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl (2), were synthesized from 4-fluoro-3-phenyl nitrobenzene. Two series of polyimides were synthesized from these diamines with nine types of dianhydrides by a conventional two-step procedure that included ring-opening polymerization in N-methyl-2-pyrrolidone and subsequent thermal cyclic dehydration. The polyimides were characterized by x-ray diffraction, differential scanning calorimetry, thermogravimetry and dynamic mechanical analysis. The polyimides from 1 and 2 had a glass transition temperature in the range of 221–254°C and 222–271°C, respectively, and all the polymers were amorphous. The structure–property relationships of these polyimides were examined and compared with those of the previously prepared analogous polyimides from the bis(4-amino-2-biphenyl)ether (3). Water absorption and dielectric constants ( ∊) of the polyimides were compared and discussed on the basis of imide content per repeating unit.

Studies on the synthesis and properties of 1,1,1-trinitroprop-2-yl urea, carbamate and nitrocarbamate

2016 ◽  
Vol 71 (7) ◽  
pp. 811-820
Author(s):  
Quirin J. Axthammer ◽  
Thomas M. Klapötke ◽  
Burkhard Krumm
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Sulfuric Acid ◽  
Electrostatic Discharge ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Propulsion Performance ◽  
Chlorosulfonyl Isocyanate ◽  
Velocity Of Detonation

AbstractPotential high energetic dense oxidizers with the 1,1,1-trinitropropan-2-yl moiety are described in this study. The urea, N,N′-bis(1,1,1-trinitropropan-2-yl)urea (1), is synthesized by the reaction of urea with acetaldehyde and trinitromethane. The reaction of 1,1,1-trinitropropan-2-ol (2) with the reagent chlorosulfonyl isocyanate results in the formation of 1,1,1-trinitroprop-2-yl carbamate (3). The nitration of 3 with anhydrous nitric and sulfuric acid yields the nitrocarbamate (4). All compounds were fully characterized by multinuclear NMR (1H, 13C, 14/15N) and vibrational spectroscopy, mass spectrometry and elemental analysis (C,H,N). For analysis of the thermostability differential scanning calorimetry (DSC) was used. Energetic properties, the sensitivities towards impact, friction and electrostatic discharge were tested and compared with the corresponding 2,2,2-trinitroethyl and 3,3,3-trinitropropyl derivatives. The crystal structures of two compounds with that of the 1,1,1-trinitroprop-2-yl moiety have been determined by low temperature X-ray diffraction and discussed. The energies of formation were evaluated and several detonation parameters such as the velocity of detonation and the propulsion performance were calculated with the program package explo5.

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