Study on Mechanical Properties of PP Modified by β Nucleating Agent under the Low Temperature

2013 ◽  
Vol 710 ◽  
pp. 97-101
Author(s):  
Jiang Zhu ◽  
Xiang Liu ◽  
Qiang Xu ◽  
Liang Cao
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Room Temperature ◽  
Bending Strength ◽  
Nucleating Agent ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
X Ray ◽  
The Impact

The ethylene-propylene polymer (PP) was modified by using a rare earth β-nucleating agent (WBG-II). The crystallization characteristics of PP induced by WBG-II were investigated through the wide-angle X-ray diffraction (WAXD). The effect of β-nucleating agent on the mechanical property of PP under low temperature was also researched. The results confirmed that β-nucleating agent WBG-II can change the crystal structure of PP and induce the β-form crystals in the PP to develop. Moreover, under the room temperature, with the increment of WBG-II, the tensile strength, bending strength and modulus of the modified PP increase, but the impact strength and elongation at break decrease; and especially at-10 °C, this tendency is more obvious.

Low-temperature crystal structure of RS-thiocamphor

2004 ◽  
Vol 219 (9) ◽  
Author(s):  
E. Louise R. Robins ◽  
Michela Brunelli ◽  
Asiloé J. Mora ◽  
Andrew N. Fitch
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Low Temperature ◽  
Room Temperature ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Two Phase ◽  
X Ray ◽  
Low Temperature Crystal Structure

AbstractDSC and high-resolution powder X-ray diffraction measurements in the range 295 K–100 K show that RS-thiocamphor undergoes two phase transitions. The first, at around 260 K on cooling, is from the room-temperature body-centred-cubic phase to a short-lived intermediate. At 258 K the low-temperature form starts to appear. The crystal structure of the latter is orthorhombic, space group

Effect of Molybdenum and Ruthenium on the Crystallization Tendency of a New Nuclear Glass Containing High Rare-earth Concentration

2010 ◽  
Vol 1265 ◽  
Author(s):  
Daniel Caurant ◽  
Nolwenn Chouard ◽  
Odile Majerus ◽  
Jean-Luc Dussossoy ◽  
Aurelien Ledieu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Nucleating Agent ◽  
High Level Waste ◽  
Optical Absorption Spectroscopy ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Level ◽  
The Impact ◽  
Crystallization Tendency

AbstractThe impact of Nd2O3, MoO3 and RuO2 addition on the competition between the crystallization of apatite Ca2Nd8(SiO4)6O2 and powellite CaMoO4 phases which both may appear in High Level Waste nuclear glass (under certain specific conditions of cooling and glass composition) has been studied on a simplified composition belonging to the system SiO2-Na2O-CaO-Al2O3-B2O3. X-ray diffraction (at room temperature and high temperature) and scanning electron microscopy measurements have been performed on five glasses under two different thermal treatments. We show that RuO2 acts as a nucleating agent for apatite. Moreover, neodymium and molybdenum cations seem to be very close in the glassy network as Nd2O3 addition stops the phase separation of molybdates and inhibits the crystallization of CaMoO4. On the contrary, MoO3 seems to favor the crystallization of apatite. For several samples, the evolution of the distribution of Nd3+ cations after crystallization was followed by optical absorption spectroscopy.

The crystal structure and temperature dependence of the elpasolite Tl2LiYCl6

2021 ◽  
Vol 54 (2) ◽  
Author(s):  
Drew R. Onken ◽  
Didier Perrodin ◽  
Edith D. Bourret ◽  
Sven C. Vogel
Keyword(s):  
Crystal Structure ◽  
Gamma Rays ◽  
Room Temperature ◽  
Structural Transition ◽  
Radiation Detection ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Industry Standard ◽  
The Impact

Tl2LiYCl6 (TLYC) is an analog to Cs2LiYCl6, which is currently an industry-standard inorganic scintillator for radiation detection with good gamma–neutron discrimination. The presence of thallium (Z = 81) instead of cesium (Z = 55) in the elpasolite structure increases the density of the compound and its stopping power for gamma rays. This work investigates the impact of the Tl atom on the elpasolite structure. Single-crystal X-ray diffraction at room temperature and powder neutron diffraction with temperature control were used to characterize the crystal structure of TLYC between 296 and 725 K. The presence of Tl leads to a distortion of the cubic elpasolite structure at room temperature: a tetragonal P42 crystal structure (space group 77, a = 10.223, c = 10.338 Å) is identified for TLYC at 296 K. A structural transition to the cubic elpasolite Fm 3 m phase (space group 225) is observed at 464 K. The thermal expansion of the material for each crystal direction is well described by a linear relationship, except for the region between 400 and 464 K where the lattice parameters converge.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

scholarly journals c-Perpendicular Orientation of Poly(ʟ-lactide) Films

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1572
Author(s):  
Baku Nagendra ◽  
Paola Rizzo ◽  
Christophe Daniel ◽  
Lucia Baldino ◽  
Gaetano Guerra
Keyword(s):  
Low Temperature ◽  
Film Plane ◽  
Wide Angle ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Amorphous Films ◽  
High Transparency ◽  
X Ray ◽  
Crystalline Forms ◽  
Induced Crystallization

Poly(ʟ-lactide) (PLLA) films, even of high thickness, exhibiting co-crystalline and crystalline α phases with their chain axes preferentially perpendicular to the film plane (c⊥ orientation) have been obtained. This c⊥ orientation, unprecedented for PLLA films, can be achieved by the crystallization of amorphous films as induced by low-temperature sorption of molecules being suitable as guests of PLLA co-crystalline forms, such as N,N-dimethylformamide, cyclopentanone or 1,3-dioxolane. This kind of orientation is shown and quantified by two-dimensional wide-angle X-ray diffraction (2D-WAXD) patterns, as taken with the X-ray beam parallel to the film plane (EDGE patterns), which present all the hk0 arcs centered on the meridian. PLLA α-form films, as obtained by low-temperature guest-induced crystallization, also exhibit high transparency, being not far from those of the starting amorphous films.

Evolution of crystal structure of dual layered molecular conductor (ET)4ZnBr4(C6H4Cl2) with temperature

CrystEngComm ◽  
2021 ◽  
Author(s):  
Gennady V. Shilov ◽  
Elena I. Zhilyaeva ◽  
Sergey M. Aldoshin ◽  
Alexandra M Flakina ◽  
Rustem B. Lyubovskii ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Resistivity ◽  
Single Crystal ◽  
Room Temperature ◽  
Organic Conductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Molecular Conductor ◽  
Abrupt Changes

Electrical resistivity measurements of a dual layered organic conductor (ET)4ZnBr4(1,2-C6H4Cl2) above room temperature show abrupt changes in resistivity at 320 K. Single-crystal X-ray diffraction studies in the 100-350 K range...

CRYSTAL STRUCTURE OF ZIRCONIUM TRICHLORIDE

1964 ◽  
Vol 42 (10) ◽  
pp. 1886-1889 ◽  
Author(s):  
B. Swaroop ◽  
S. N. Flengas
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Main Cell ◽  
Diffraction Patterns

The crystal structure of zirconium trichloride was determined from X-ray diffraction patterns. Zirconium trichloride belongs to the [Formula: see text]space group. The dimensions of the main cell at room temperature are: a = 5.961 ± 0.005 Å and c = 9.669 ± 0.005 Å.The density of zirconium trichloride was measured and gave the value of 2.281 ± 0.075 g/cm3 while, from the X-ray calculations, the value was found to be 2.205 g/cm3.

Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermal Effects ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Scanning Calorimetry ◽  
X Ray

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.

Ein tricyclisches Tetraboradisiladodecan aus Dimethyl-di-1-propinylsilan und Ethyldiboranen(6) / A Tricyclic Tetraboradisiladodecane from Dimethyl-di-1-propynylsilane and Ethyldiboranes(6)

1995 ◽  
Vol 50 (3) ◽  
pp. 439-447 ◽  
Author(s):  
Roland Köster ◽  
Günter Seidel ◽  
Roland Boese ◽  
Bernd Wrackmeyer
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Thermal Elimination

The exhaustive hydroboration of the (C ≡ C )-groups in Me2Si(C ≡ CMe)2 (A ) by adding ethyldiboranes(6) at room temperature is presumed to lead initially to the formation of a mixture of the threo- and erythro-3,3,5,6-tetrakis(diethylboryl)-4,4-dimethyl-4-silaheptanes (1a , b). The threo-1a reacts further by borane catalysed intermolecular condensation to the substituted disilatetraboratricyclo[6.2.1.16.9]dodecane 2 with the formula , whose crystal structure [space group C2/c, a = 19.696(2), b = 10.371(1), c = 16.580(2) Å; β = 125.90(1)°; at 122 K] has been established by X -ray diffraction. In contrast, the erythro-1b undergoes intramolecular, thermal elimination of Et3B to give the 1,2-diethyl-2,4-bis(diethylboryl)- 3,3,5-trim ethyl-3-silaborolane (4). If A is added to an excess of undiluted B (“hydridebath”), then the two substituted diastereomers of the 1-carba-arachno-pentaboranes(10) (endo/exo-Et,SiH Me2) (3a, b), are formed preferentially as the result of an initial Si-C ≡-c le a v e d hydroboration.

X-ray Diffraction Studies of Solid Solutions of Pentaglycerine-Neopentylglycol

1988 ◽  
Vol 32 ◽  
pp. 609-616 ◽  
Author(s):  
D. Chandra ◽  
C. S. Barrett ◽  
D. K. Benson
Keyword(s):  
Crystal Structure ◽  
Energy Storage ◽  
Hydrogen Bonds ◽  
Solid Solutions ◽  
Room Temperature ◽  
Energy Storage Materials ◽  
Anisotropic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cubic Structure

AbstractAn array of molecules that is anisotropic in the extreme has been discovered in certain thermal-energy storage materials and is reported here: neopentylglycol (NPG) and NPG-rich solid solutions with pentaglycerine (PG) have a crystal structure, stable at room temperature, that consists of bimolecular chains of molecules that are all unidirectionally aligned throughout a crystal. There are hydrogen bonds between every molecule in one chain and its neighbors in that chain, but none between molecules of one chain and any molecules of the neighboring parallel chains. Thus there are strong intermolecular bonds along each chain and only weaker bonds between the chains. The structure has been determined by using modern single crystal techniques with 529 independent reflections from a crystal of NPG (C5H12O2). The structure is monoclinic with space group P21/c - C2h5. This anisotropic structure transforms to a cubic structure at higher temperatures.

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