scholarly journals Processing of Polypropylene-Organic Montmorillonite Nanocomposite by Equal Channel Multiangular Extrusion

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
V. A. Beloshenko ◽  
A. V. Voznyak ◽  
Yu. V. Voznyak ◽  
L. A. Novokshonova ◽  
V. G. Grinyov ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Structure Analysis ◽  
Lamellar Thickness ◽  
Polymeric Nanocomposites ◽  
X Ray ◽  
Organic Montmorillonite ◽  
Heat Distortion Temperature ◽  
Crystallite Thickness

By the example of polypropylene-organic montmorillonite composite (PP-OMMT), the abilities of the method of equal channel multiangular extrusion have been studied with respect to the modification of the structure and the properties of polymeric nanocomposites. With using X-ray structure analysis, TEM, DSC, and dilatometry, it has been demonstrated that this kind of processing provides an additional intercalation of the polymer into OMMT tactoids with the succeeding exfoliation and facilitates an increase in the aspect ratio, the degree of platelet orientation, the crystalline lamellar thickness, and a decrease in the dispersion of the crystallite thickness, as well as the formation of biaxial orientation of the OMMT and PP crystals. The observed structure rearrangements determine enhanced microhardness, ductility, and the heat distortion temperature of the PP-OMMT composite.

Absolute Stereochemistry of (-)-Wieland-Miescher Ketone as Established by the X-ray Crystallographic and CD Exciton Chirality Methods

1992 ◽  
Vol 57 (7) ◽  
pp. 1459-1465 ◽  
Author(s):  
Nobuyuki Harada ◽  
Tatsuo Sugioka ◽  
Hisashi Uda ◽  
Takeo Kuriki
Keyword(s):  
Structure Analysis ◽  
Absolute Configuration ◽  
X Ray ◽  
The Absolute ◽  
Absolute Stereochemistry

The 8aR absolute stereochemistry of Wieland-Miescher ketone (-)-I was established by the X-ray structure analysis of its bis(4-bromobenzoate) derivatives (1R,6R,8aR)-(+)-IV and (1R,6S,8aR)-(-)-V. The absolute configuration of (-)-I was corroborated further by the application of the CD exciton chirality method to bis(4-bromobenzoates) (+)-IV and (-)-V.

scholarly journals Preparative-scale HPLC Resolution of Metallacyclic η3-Allyltricarbonyliron Complexes and Determination of the Absolute Configuration by X-Ray Crystal Structure Analysis

1999 ◽  
Vol 23 (9) ◽  
pp. 578-579
Author(s):  
Rainer Schobert ◽  
Hermann Pfab ◽  
Jutta Böhmer ◽  
Frank Hampel ◽  
Andreas Werner
Keyword(s):  
Crystal Structure ◽  
Silica Gel ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
Preparative Scale ◽  
X Ray ◽  
The Absolute

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.

scholarly journals NMR, X-Ray and MS Investigations of Ethyl 2-Aroyl-and Ethyl 2-Arylcarbamoyl-4,5- dimethyl-1,2,3,6-tetrahydropyridazine-1- carboxylates: Flexible Multidentate Ligands

1999 ◽  
Vol 23 (3) ◽  
pp. 186-187
Author(s):  
Erkki Kolehmainen ◽  
Katri Laihia ◽  
Maija Nissinen ◽  
Kalevi Pihlaja ◽  
Alexander Perjéssy ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Multidentate Ligands ◽  
X Ray ◽  
C Nmr

The 1H and 13C NMR spectral assignments of ethyl 2-aroyl-4,5-dimethyl-1,2,3,6-tetrahydropyridazine-1-carboxylates (1a-1h) and ethyl 2-arylcarbamoyl-4,5-dimethyl-1,2,3,6-tetrahydropyridazine-1-carboxylates (2a-2k) are given based on DQF COSY, 1H,13C HMQC and 1H,13C HMBC-measurements; the dynamics of the tetrahydropyridazine ring has been studied by 1H, 1H EXSY-technique and the structure of one congener (4′-methylphenyl-derivative, 2a) has been confirmed by X-ray structure analysis.

Second-Generation Inhibitors for the Metalloprotease Neprilysin Based on Bicyclic Heteroaromatic Scaffolds: Synthesis, Biological Activity, and X-Ray Crystal-Structure Analysis

2005 ◽  
Vol 88 (4) ◽  
pp. 731-750 ◽  
Author(s):  
Stefan Sahli ◽  
Brian Frank ◽  
W. Bernd Schweizer ◽  
François Diederich ◽  
Denise Blum-Kaelin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biological Activity ◽  
Structure Analysis ◽  
Second Generation ◽  
Crystal Structure Analysis ◽  
X Ray

High length-to-width aspect ratio lead bromide microwires via perovskite-induced local concentration gradient for X-ray detection

CrystEngComm ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 2215-2221
Author(s):  
Emma Dennis ◽  
Soumya Kundu ◽  
Deepak Thrithamarassery Gangadharan ◽  
Jingjun Huang ◽  
Victor M. Burlakov ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Concentration Gradient ◽  
Width Ratio ◽  
Local Concentration ◽  
X Ray ◽  
Lead Bromide ◽  
High Length

Well-oriented PbBr2 microwires with a length-to-width ratio of up to 5000 were grown using a concentration gradient in co-crystallization with perovskite. Planar-integrated microwires showed a response to X-ray photons.

Regiospezifische Insertion von [SCN]- und [SeCN]- in die S – C- bzw. Se– C-Bindung Übergangsmetall-koordinierter Thietane und SelenetaneRegiospecific Insertion of [SCN]- and [SeCN]- in the S–C- and Se–C-Bond of Transition-Metal-Coordinated Thietanes and Selenetanes

1993 ◽  
Vol 48 (11) ◽  
pp. 1613-1620 ◽  
Author(s):  
Helmut Fischer ◽  
Claudia Kalbas ◽  
Carsten Troll ◽  
Klaus H. Fluck
Keyword(s):  
Nitrogen Atom ◽  
Transition Metal ◽  
Structure Analysis ◽  
Trans Isomer ◽  
X Ray ◽  
Tungsten Complexes ◽  
Membered Heterocycle

Pentacarbonyl(thietane)tungsten complexes react with thiocyanate, [SCN]-, and SiO2/H2O by insertion of the CN group into a S—C bond of the four-membered heterocycle, 1,3-migration of the pentacarbonyltungsten fragment and protonation of the nitrogen atom to give tungsten-coordinated thiazinthione complexes. Analogously, the reactions of a thietane tungsten complex with [SeCN]- and SiO2/H2O affords a thiazinselone complex. A selenazinthione complex is obtained from a selenetane complex and [SCN]- (+ SiO2/H2O). The insertions are regiospecific and stereoselective. The structure of the trans-isomer of a pentacarbonyl-(thiazinthione) complex has been established by X-ray structure analysis.

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