High Yield Polyborosilazane Precursor for SiBN Ceramics

2014 ◽  
Vol 1004-1005 ◽  
pp. 409-414 ◽  
Author(s):  
Shuai Yong Jin ◽  
Kang Kang Guo ◽  
Hui Min Qi ◽  
Ya Ping Zhu ◽  
Fan Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Yield ◽  
Cross Linking ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Ceramic Yield ◽  
X Ray ◽  
Amorphous Structures

The processible and high yield polyborosilazane (PBSZ) precursor for SiBN ceramics was prepared by coammonolysis reaction of dichlorosilane and trichloroborazine. The synthesized PBSZ precursor was characterized by Fourier Transform Infrared spectroscopy (FTIR),1H,11B, and29Si Nuclear Magnetic Resonance (NMR), and its ceramic conversion chemistry was investigated by differential scanning calorimetric (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA). The PBSZ precursor is a viscous liquid and changes to an insoluble solid via a cross-linking reaction between the N-H group and Si-H group as post-heated from 60 to 180°C. The insoluble solid is transformed to Si3N4and BN amorphous structures with an approximately 95% ceramic yield after being pyrolyzed to 1000°C.

High-yield, regiospecific bis-functionalization of C70 using a Diels–Alder reaction in molten anthracene

2014 ◽  
Vol 50 (73) ◽  
pp. 10584-10587 ◽  
Author(s):  
Venkata S. Pavan K. Neti ◽  
Maira R. Cerón ◽  
A. Duarte-Ruiz ◽  
Marilyn M. Olmstead ◽  
Alan L. Balch ◽  
...  
Keyword(s):  
Single Crystal ◽  
Thermal Gravimetric Analysis ◽  
Alder Reaction ◽  
Diels Alder ◽  
High Yield ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diels Alder Reaction

A regiospecific bis-adduct of C70 with anthracene was prepared with unusually high yield (68%) by the Diels–Alder reaction in the absence of solvent (melt). The structure of the bis-adduct was an unexpected 12 o'clock isomer, as determined by single crystal X-ray diffraction, thermal gravimetric analysis (TGA) and spectroscopy.

scholarly journals Synergistic interaction of renewable nipagin and eugenol for high performance aromatic copoly(ether ester) materials

2021 ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao
Keyword(s):  
High Performance ◽  
Synergistic Interaction ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Naturally Occurring ◽  
Ether Ester

Abstract Naturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) materials. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11-xE1x and PHN11-xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggest that properties of such kind of poly(ether ester)s can be finely tuned by the relative content of two components. Synergistic interaction of two structurally distinctive parts endows the materials with high performance.

Synthesis of Novel Carbon Spheres and Study on Graphitization Process

2013 ◽  
Vol 634-638 ◽  
pp. 2293-2296
Author(s):  
Ai Li Ma ◽  
Cheng Qian Li ◽  
Wu Qing Du ◽  
Jie Chang
Keyword(s):  
High Temperature ◽  
Microwave Plasma ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Carbon Spheres ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cvd Method ◽  
Graphitization Degree ◽  
Scanning Electron

In this paper, carbon spheres were synthesized by CVD method. These carbon spheres exhibit diameters of about 200 nm. Thermal gravimetric analysis indicated the good stability in high temperature of the carbon spheres. The products were treated by microwave plasma and high temperature vacuum heat treatments respectively. The products were characterized by X-ray diffraction, Raman spectroscopy and Field Emission Scanning Electron Microscope. The study indicated that the original products, with perfect morphology and low graphitization degree, were converted to crystal. The different techniques were considered for the influence on the graphitization degree.

Study on the Preparation and Properties of EVA-G-PU/OMMT Nanocomposites

2010 ◽  
Vol 123-125 ◽  
pp. 247-250
Author(s):  
Yu Qing Zhang ◽  
Yu Xin He ◽  
Li Zhang ◽  
Jun Xian Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Clay Nanocomposites ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Thermal Stabilities ◽  
X Ray ◽  
Transmission Electron ◽  
New Type

A new type of EVA-g-PU/OMMT nanocomposites was synthesized through the method of chemical modification and melt intercalation. FTIR testing showed that the PU prepolymer was grafted on EVA main chains successfully. The structures of EVA-g-PU/OMMT nanocomposites were characterized by X-ray diffraction (XRD) and by high-resolution transmission electron microscopy (HRTEM). The enhanced storage modulus of EVA-g-PU/OMMT nanocomposites was characterized by dynamic mechanical analysis (DMA). The thermal stabilities of EVA/clay nanocomposites were also studied by thermal gravimetric analysis (TGA). Mechanical testing showed that the tensile strength and tear strength of EVA-g-PU/OMMT nanocomposites were far superior to pure EVA.

scholarly journals High Active Co/Mg1-xCex3+O Catalyst: Effects of Metal-Support Promoter Interactions on CO2 Reforming of CH4 Reaction

2021 ◽  
Vol 16 (1) ◽  
pp. 97-110
Author(s):  
Faris A. Jassim Al-Doghachi ◽  
Diyar M. A. Murad ◽  
Huda S. Al-Niaeem ◽  
Salam H. H. Al-Jaberi ◽  
Surahim Mohamad ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Dry Reforming Of Methane ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co2 Reforming Of Ch4 ◽  
Temperature Programmed

Co/Mg1−XCe3+XO (x = 0, 0.03, 0.07, 0.15; 1 wt% cobalt each) catalysts for the dry reforming of methane (DRM) reaction were prepared using the co-precipitation method with K2CO3 as precipitant. Characterization of the catalysts was achieved by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H2-TPR), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The role of several reactant and catalyst concentrations, and reaction temperatures (700–900 °C) on the catalytic performance of the DRM reaction was measured in a tubular fixed-bed reactor under atmospheric pressure at various CH4/CO2 concentration ratios (1:1 to 2:1). Using X-ray diffraction, a surface area of 19.2 m2.g−1 was exhibited by the Co/Mg0.85Ce3+0.15O catalyst and MgO phase (average crystallite size of 61.4 nm) was detected on the surface of the catalyst. H2 temperature programmed reaction revealed a reduction of CoO particles to metallic Co0 phase. The catalytic stability of the Co/Mg0.85Ce3+0.15O catalyst was achieved for 200 h on-stream at 900 °C for the 1:1 CH4:CO2 ratio with an H2/CO ratio of 1.0 and a CH4, CO2 conversions of 75% and 86%, respectively. In the present study, the conversion of CH4 was improved (75%–84%) when conducting the experiment at a lower flow of oxygen (1.25%). Finally, the deposition of carbon on the spent catalysts was analyzed using TEM and Temperature programmed oxidation-mass spectroscopy (TPO-MS) following 200 h under an oxygen stream. Better anti-coking activity of the reduced catalyst was observed by both, TEM, and TPO-MS analysis. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals Utilization of cajuput (Melaleuca leucadendron) twigs and sugarcane (Saccharum officinarum) bagasse agricultural waste for cellulose acetate production by environmentally friendly approach

2021 ◽  
Author(s):  
Roni Maryana ◽  
Muryanto Muryanto ◽  
Eka Triwahyuni ◽  
Oktaviani Oktaviani ◽  
Hafiizh Prasetia ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Thermal Gravimetric Analysis ◽  
Agricultural Waste ◽  
Environmentally Friendly ◽  
Saccharum Officinarum ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray

Abstract This study was carried out to investigate the extraction of cellulose acetate (CA) from cajuput (Melaleuca leucadendron) twigs and sugarcane (Saccharum officinarum) bagasse using an environmentally friendly method. At first, cellulose was extracted from cajuput twigs (CT) and sugarcane bagasse (SB) through prehydrolysis followed by soda (NaOH) pulping and elementary chlorine-free (ECF) bleaching. Later, the extracted cellulose was acetylated using iodine (I) as a catalyst. The obtained CA was characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), thermal gravimetric analysis (TGA), scanning electron microscope (SEM) and X-ray diffraction. FTIR and NMR analysis proved the replacement of free OH (hydroxyl) groups by acetyl groups. The degree of substitution (DS) showed the acetylation capability of cellulose extracted from CT and SB as well. The cellulose diameter and its crystallinity index were measured by SEM and X-ray diffraction, respectively. Furthermore, the thermal gravimetric analysis showed that CA extracted from CT and SB was thermal resistance. Therefore, CT and SB could be potential alternative resources for CA production using the mentioned method.

Arc Discharge Synthesis of Oxides and Carbides of Tungsten and Aluminum

2013 ◽  
Vol 8 (2) ◽  
pp. 95-101
Author(s):  
Alexey Zaikovsky ◽  
Aleksandr Fedoseev ◽  
Salavat Sakhapov ◽  
Anton Evtushenko ◽  
Marina Serebriakova ◽  
...  
Keyword(s):  
Arc Discharge ◽  
Experimental Investigations ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Of Nanoparticles ◽  
Synthesized Materials ◽  
Discharge Method

Experimental investigations of the possibility of arc discharge method for synthesis of nanoparticles of oxides and carbides of tungsten and aluminum have been presented. The method is based on anode atomization of composed graphite – aluminum and graphite – WO3 electrodes. The transmitted electron microscopy, thermal gravimetric analysis and X-ray diffraction were applied for the characterization of morphology and properties of synthesized materials. It was experimentally shown the arc discharge method allows to syntheses the nanoparticles of oxides and carbides of tungsten and aluminum

Evaluation on Microstructure Stability and Thermal Resistant Ability at High Temperature of Ternary-Blended Geopolymer

2021 ◽  
Vol 321 ◽  
pp. 73-79
Author(s):  
Hoc Thang Nguyen
Keyword(s):  
High Temperature ◽  
Rice Husk Ash ◽  
High Thermal Stability ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Stability ◽  
Before And After ◽  
Materials Used

Stability of microstructure and heat resistant ability at high temperature is one of the important properties in ceramics or silicate materials which are normally exposed with fire such as refractories and insulation or other materials used in furnaces. This study used a ternary-blended geopolymer which was synthesized from an optimized mixture of red mud (RM), rice husk ash (RHA), diatomaceous earth (DE), and water glass solution (WGS) with silica modulus of 2.5. The geopolymer samples were tested thermal properties of heat resistance (%), volumetric shrinkage (%), mass loss (%) at 1000°C to evaluate thermal resistant ability. Changes of microstructure of the ternary-blended geopolymer samples were also characterized before and after exposed at high temperature using methods of X-ray diffraction (XRD), Thermogravimetric analysis or thermal gravimetric analysis (DTA-TGA), and Scanning electron microscope (SEM). The experimental results showed the ternary-blended geopolymer has high thermal stability and unchanged microstructure even at high temperatures. Hence, the geopolymer in this study is suggested to apply as an insolation with the upper limit of temperature to work at 1000°C.

Crystal structure and physical properties of a new two-dimensional zinc coordination polymer based on 1,4-bis(4-(imidazole-1-yl)benzyl)piperazine and benzophenone-2,4′-dicarboxylate ligands

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xin-Yue Zhang ◽  
Chen Zhang ◽  
Jun Wang ◽  
Xiao-Juan Xu
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Catalytic Properties ◽  
Gravimetric Analysis ◽  
Two Dimensional ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zinc Coordination ◽  
Oriented Parallel

Abstract A new 2-dimensional (2D) zinc(II) coordination polymer based on a flexible bis(imidazole) ligand, namely, [Zn2(BIBP)(BPDC)2·DMF] n (1) BIBP is 1,4-bis(4-(imidazole-1-yl)benzyl)piperazine and H2BPDC is benzophenone-2,4′-dicarboxylic acid), has been synthesized and characterized through single-crystal X-ray diffraction, infrared (IR) spectroscopy, and elemental and thermal gravimetric analysis. Complex 1 exhibits a 2D framework oriented parallel to [0 2 1] based on [Zn(BPDC)] n chains. The fluorescence and catalytic properties of complex 1 for the photodegradation of methylene blue were investigated.

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