A Study of the Interactions Between Oligoamidephosphate (OAPh) and Curatives in a Sulphenamide-Accelerated Sulphur Vulcanizing System

1999 ◽  
Vol 19 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Todorka G. Vladkova ◽  
Alexander Chr. Alaminov ◽  
Milka G. Pankova

Abstract The possible interactions between oligoamidephosphate (OAPli) and the curatives of a sulphenamide-accelerated sulphur vulcanizing system were studied by differential scanning calorimetry, IR-spectroscopy, and X-ray analysis. The interactions in double mixtures were between OAPh and zinc oxide (ZnO) and OAPh and sulphur. The OAPh/ZnO interaction that starts at room temperature seems to be the key for understanding the peculiarities of sulphenamide-accelerated sulphur vulcanization in the presence of OAPh.

2012 ◽  
Vol 535-537 ◽  
pp. 950-953
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Zhi Jian Duan ◽  
Jian Jun Zhang

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It is Observed through the experiment: the addition of Gd enhances martensite transition temperature;X-ray diffraction analysis of experimental alloys is revealed that to the mixture is martensite and austenite at room temperature; content of Gd is not proportional to the improvement of magnetic property.


2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.


1998 ◽  
Vol 76 (11) ◽  
pp. 1520-1523
Author(s):  
Jennifer F Caplan ◽  
Christopher A Murphy ◽  
Susan Swansburg ◽  
Robert P Lemieux ◽  
T Stanley Cameron ◽  
...  

The synthesis of Ru2(μ-O2CR)4(μ´-O2CR) (1), R = -CH2(CH2)6CH=CH(CH2)5CH3, has been achieved and characterization using elemental analysis and FTIR and UV-Vis spectroscopies undertaken. Strong evidence for a hexagonal discotic mesophase has been found using differential scanning calorimetry, variable-temperature polarizing optical microscopy, and X-ray powder diffraction. A solid to liquid crystal transition was found upon heating at 128°C and the mesophase is found to persist to room temperature upon cooling from 150°C. This is the first report of room temperature mesomorphism in a mixed-valent metallomesogen. Key words: ruthenium carboxylate, liquid crystal, metallomesogen, mixed valence, polymer.


2019 ◽  
Vol 72 (2) ◽  
pp. 87 ◽  
Author(s):  
Hiroshi Abe ◽  
Takahiro Takekiyo ◽  
Yukihiro Yoshimura ◽  
Nozomu Hamaya ◽  
Shinichiro Ozawa

Crystal polymorphs and multiple crystallization pathways of a room-temperature ionic liquid (RTIL) were observed only under high pressure (HP). The RTIL was 1-ethyl-3-methylimidazolium nitrate, [C2mim][NO3]. The HP-crystal polymorphs were related to conformations of the C2mim+ cation, and the HP-crystal pathways determined by the presence or absence of the planar′ (P′) conformation of the C2mim+ cation were switched at the bifurcation pressure (PB). Above PB, modulated crystal structures derived from the HP-inherent P′ conformer. Simultaneous X-ray diffraction and differential scanning calorimetry measurements, accompanied by optical microscope observations, confirmed the normal low-temperature crystallization of [C2mim][NO3] under ambient pressure.


Author(s):  
Nehemiah Harris ◽  
Jubilee Benedict ◽  
Diane A. Dickie ◽  
Silvina Pagola

Quinine (an antimalarial) and aspirin (a nonsteroidal anti-inflammatory drug) were combined into a new drug–drug salt, quininium aspirinate, C20H25N2O2 +·C9H7O4 −, by liquid-assisted grinding using stoichiometric amounts of the reactants in a 1:1 molar ratio, and water, EtOH, toluene, or heptane as additives. A tetrahydrofuran (THF) solution of the mechanochemical product prepared using EtOH as additive led to a single crystal of the same material obtained by mechanochemistry, which was used for crystal structure determination at 100 K. Powder X-ray diffraction ruled out crystallographic phase transitions in the 100–295 K interval. Neat mechanical treatment (in a mortar and pestle, or in a ball mill at 20 or 30 Hz milling frequencies) gave rise to an amorphous phase, as shown by powder X-ray diffraction; however, FT–IR spectroscopy unambiguously indicates that a mechanochemical reaction has occurred. Neat milling the reactants at 10 and 15 Hz led to incomplete reactions. Thermogravimetry and differential scanning calorimetry indicate that the amorphous and crystalline mechanochemical products form glasses/supercooled liquids before melting, and do not recrystallize upon cooling. However, the amorphous material obtained by neat grinding crystallizes upon storage into the salt reported. The mechanochemical synthesis, crystal structure analysis, Hirshfeld surfaces, powder X-ray diffraction, thermogravimetry, differential scanning calorimetry, FT–IR spectroscopy, and aqueous solubility of quininium aspirinate are herein reported.


2012 ◽  
Vol 535-537 ◽  
pp. 959-963
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Jing Xin ◽  
Jian Jun Zhang

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It shows that addition of Gd enhances martensite transition temperature and that X-ray diffraction analysis of experimental alloys is revealed which the mixture is martensite and austenite at room temperature. These alloys show promise as a metamagnetic shape memory alloy with magnetic-field-induced shape memory effect.


1997 ◽  
Vol 12 (2) ◽  
pp. 402-406 ◽  
Author(s):  
X. Cao ◽  
R. Prozorov ◽  
Yu. Koltypin ◽  
G. Kataby ◽  
I. Felner ◽  
...  

A method for the preparation of pure amorphous Fe2O3 powder with particle size of 25 nm is reported in this article. Pure amorphous Fe2O3 can be simply synthesized by the sonication of neat Fe(CO)5 or its solution in decalin under an air atmosphere. The Fe2O3 nanoparticles are converted to crystalline Fe3O4 nanoparticles when heated to 420 °C under vacuum or when heated to the same temperature under a nitrogen atmosphere. The crystalline Fe3O4 nanoparticles were characterized by x-ray diffraction and M¨ossbauer spectroscopy. The Fe2O3 amorphous nanoparticles were examined by Transmission Electron Micrography (TEM), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and Quantum Design SQUID magnetization measurements. The magnetization of pure amorphous Fe2O3 at room temperature is very low (<1.5 emu/g) and it crystallizes at 268 °C.


2019 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Takanori Fukami ◽  
Shuta Tahara ◽  
Arbi Dimyati

Manganese L-tartrate dihydrate, L-MnC4H4O6&middot;2H2O, and manganese DL-tartrate dihydrate, DL-MnC4H4O6&middot;2H2O, crystals were grown at room temperature by the gel method using silica gels as the growth medium. Differential scanning calorimetry, thermogravimetric-differential thermal analysis, and X-ray diffraction measurements were performed on both crystals. The space group symmetries (monoclinic P21 and P2/c) and structural parameters of the crystals were determined at room temperature. Both structures consisted of slightly distorted MnO6 octahedra, C4H4O6 and H2O molecules, and O&ndash;H&middot;&middot;&middot;O hydrogen-bonding frameworks between adjacent molecules. Weight losses due to thermal decomposition of the crystals were found to occur in the temperature range of 300&ndash;1150 K. We inferred that the weight losses were caused by the evaporation of bound 2H2O molecules, and the evolutions of gases from C4H4O4 and of (1/2)O2 gas from MnO2, and that the residual black substance left in the vessels after decomposition was manganese oxide (MnO).


Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3936 ◽  
Author(s):  
Huahui Zeng ◽  
Jing Xiong ◽  
Zhuang Zhao ◽  
Jingyi Qiao ◽  
Duanjie Xu ◽  
...  

Three co-formers of 2-chloro-4-nitroaniline (CNA), 2,5-dihydroxybenzoic acid (DHB), and 4,4′-biphenol (DOD) were selected to prepare the co-crystal of progesterone (PROG) based on crystal engineering strategies. These co-crystals were successfully obtained via slow evaporation from different solutions and were characterized by single-crystal X-ray diffraction spectroscopy, powder X-ray diffraction, IR spectroscopy, and differential scanning calorimetry. Different binding networks were observed in the co-crystal structures of PROG. The PROG-CNA co-crystal had the fastest rates and highest concentrations of PROG in PBS solution compared with PROG or other co-crystals in the dissolution experiments. This might be attributable to more stable and abundant interactions between the PROG and CNA molecules. Our investigations provide positive support for the selection of suitable co-formers using crystal engineering strategies.


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7319
Author(s):  
Fu-Qiang Bi ◽  
Yi-Fen Luo ◽  
Jun-Lin Zhang ◽  
Huan Huo ◽  
Bo-Zhou Wang

Rearrangement reactions are efficient strategies in organic synthesis and contribute enormously to the development of energetic materials. Here, we report on the preparation of a fused energetic structure of 7-nitro-3,5-dihydro-4H-pyrazolo[4,3-d][1,2,3]triazin-4-one (NPTO) based on a novel Hofmann-type rearrangement. The 1,2,3-triazine unit was introduced into the fused bicyclic skeleton from a pyrazole unit for the first time. The new compound of NPTO was fully characterized using multinuclear NMR and IR spectroscopy, elemental analysis as well as X-ray diffraction studies. The thermal behaviors and detonation properties of NPTO were investigated through a differential scanning calorimetry (DSC-TG) approach and EXPLO5 program-based calculations, respectively. The calculation results showed similar detonation performances between NPTO and the energetic materials of DNPP and ANPP, indicating that NPTO has a good application perspective in insensitive explosives and propellants.


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