Thermal Conversion of Preceramic Polysilazanes to Si3N4: Characterization of Pyrolysis Prooucts

1986 ◽  
Vol 73 ◽  
Author(s):  
Kenneth B. Schwartz ◽  
David J. Rowcliffe ◽  
Yigal D. Blum ◽  
Richard M. Laine
Keyword(s):  
Ceramic Material ◽  
Spectroscopic Analysis ◽  
Thermal Conversion ◽  
Dense Material ◽  
Gas Evolution ◽  
Pyrolysis Products ◽  
Polymeric Precursors ◽  
Viscous Liquids ◽  
Sem Investigation

ABSTRACTCharacterization of the pyrolysis products of preceramic polysilazanes synthesized by reactions of the oligomer-[H2SiNMe]x in the presence of Ru3 (CO)12 catalyst has demonstrated that these polymers have great potential as precursors of Si3N4 for several applications. The polysilazanes studied are viscous liquids that can be converted to ceramic material with a yield of >65 wt %. The vitreous product contains regions of fully dense material and large cavities that indicate of considerable gas evolution. A preliminary pyrolysis sequence has been constructed based on a combination of TGA of the polymer, SEM investigation of the product, and mass spectroscopic analysis of the gases and heavy fragments released during conversion of the polysilazanes to ceramic material. This understanding of pyrolysis mechanisms will aid in developing even more effective polymeric precursors to Si3N4 and in optimizing pyrolysis procedures for a variety of useful appl ications.

Preparation and Characterization of Sic From Alkoxide-Derived Polymeric Precursors

1991 ◽  
Vol 249 ◽  
Author(s):  
Zhiping Jiang ◽  
Wendell E. Rhine
Keyword(s):  
Carbothermic Reduction ◽  
Pyrolysis Products ◽  
Polymeric Precursors ◽  
Polyfurfuryl Alcohol ◽  
Elemental Analyses ◽  
Molecular Source

ABSTRACTCrystalline SiC was prepared by carbothermic reduction of alkoxide-derived polymeric precursors under a flow of argon at 1400-1600°C. The pyrolysis products from the precursors with a molecular source of carbon, i.e., (R1)x(R2)ySiO1.5(Rl=phenyl; R2=propyl, vinyl), showed different morphologies from those of the precursors derived from TEOS and a polymeric source of carbon (polyfurfuryl alcohol). Furthermore, the pyrolysis chemistry of theses precursors and the microstructure of their corresponding pyrolysis products were studied by means of FTIR, TGA, XRD, SEM, BET, elemental analyses, etc.

Energia da Biomassa: termoconversão e seus produtos

2020 ◽  
Author(s):  
Lisiane dos Santos Freitas ◽  
Roberta Menezes Santos ◽  
Diego Fonseca Bispo ◽  
Thainara Bovo Massa ◽  
Thiago Vinícius Barros ◽  
...  
Keyword(s):  
Economic Value ◽  
Thermal Conversion ◽  
Chemical Characteristics ◽  
Pyrolysis Process ◽  
New Techniques ◽  
Pyrolysis Products ◽  
Critical Knowledge ◽  
Thermochemical Process ◽  
Bio Oil

In this book, the authors briefly present a description of the main pyrolysis process, the pretreatment of biomass, the characteristics of biomass, and pyrolysis products through an upgraded methods and its application. The book is divided into ten chapters dedicated to showing the potential of the thermochemical process to convert biomass into biogas, bio-oil, pyrolysis water, and biochar, which are products that can be used as intermediates in the chemical industry, in agriculture, or as biofuels. The critical knowledge of the characteristics of the biomass and possible pretreatment methods before pyrolysis can be used to help determine the routes to obtain products with superior economic value. The main types of thermal conversion, the technologies, reactors, and catalyst used to upgrade the bio-oil into biofuels, is presented is a didactic form. The characterization of classic and new techniques is addressed in order to clarify the main information obtained about the chemical characteristics of biomass and pyrolysis products. The content also shows the importance and main applications of pyrolysis products for the economy and the environment.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

Characterization of Vacuum Pyrolysis Products from Phenolic Resin Laminate Substrate

2010 ◽  
Vol 38 (1) ◽  
pp. 72-76
Author(s):  
Wen-Biao WU ◽  
Ke-Qiang QIU ◽  
Cheng-Long LI ◽  
Xiao-Qun XU
Keyword(s):  
Phenolic Resin ◽  
Pyrolysis Products ◽  
Vacuum Pyrolysis

scholarly journals Colored cotton wastes valuation through thermal and catalytic reforming of pyrolysis vapors (Py-GC/MS)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Janduir Egito da Silva ◽  
Guilherme Quintela Calixto ◽  
Rodolfo Luiz Bezerra de Araújo Medeiros ◽  
Marcus Antônio de Freitas Melo ◽  
Dulce Maria de Araújo Melo ◽  
...  
Keyword(s):  
Lignin Content ◽  
Proximate Analysis ◽  
Catalytic Reforming ◽  
Pyrolysis Products ◽  
Heating Value ◽  
Colored Cotton ◽  
Benzene Toluene ◽  
Naturally Colored Cotton ◽  
Main Influence

AbstractThis study aims to analyze the products of the catalytic pyrolysis of naturally colored cotton residues, type BRS (seeds from Brazil), called BRS-Verde, BRS-Rubi, BRS-Topázio and BRS-Jade. The energy characterization of biomass was evaluated through ultimate and proximate analysis, higher heating value, cellulose, hemicellulose and lignin content, thermogravimetric analysis and apparent density. Analytical pyrolysis was performed at 500 °C in an analytical pyrolyzer from CDS Analytical connected to a gas chromatograph coupled to the mass spectrometer (GC/MS). The pyrolysis vapors were reformed at 300 and 500 °C through thermal and catalytic cracking with zeolites (ZSM-5 and HZSM-5). It has been noticed that pyrolysis vapor reforming at 500 °C promoted partial deoxygenation and cracking reactions, while the catalytic reforming showed better results for the product deoxygenation. The catalyst reforming of pyrolysis products, especially using HZSM-5 at 500 °C, promoted the formation of monoaromatics such as benzene, toluene, xylene and styrene, which are important precursors of polymers, solvents and biofuels. The main influence on the yields of these aromatic products is due to the catalytic activity of ZSM-5 favored by increased temperature that promotes cracking reactions due expanded zeolites channels.

scholarly journals Characterization of pyrolysis products of oil palm empty fruit bunch

2021 ◽  
Vol 749 (1) ◽  
pp. 012041
Author(s):  
Slamet Handoko ◽  
N. Nurhadi ◽  
Sri mujiati ◽  
Rachma Fitriani
Keyword(s):  
Oil Palm ◽  
Empty Fruit Bunch ◽  
Pyrolysis Products

Co-combustion behavior of dyeing sludge and rice husk by using TG-MS: Thermal conversion, gas evolution, and kinetic analyses

2020 ◽  
Vol 311 ◽  
pp. 123527 ◽  
Author(s):  
Teng Wang ◽  
Tianming Fu ◽  
Kai Chen ◽  
Runshi Cheng ◽  
Si Chen ◽  
...  
Keyword(s):  
Rice Husk ◽  
Thermal Conversion ◽  
Gas Evolution ◽  
Combustion Behavior

Efficiency of sequential elution solvent chromatography-extrography technique for the characterization of hydroliquefaction and pyrolysis products

Fuel ◽  
1989 ◽  
Vol 68 (10) ◽  
pp. 1330-1335 ◽  
Author(s):  
M. Alula ◽  
M. Diack ◽  
R. Gruber ◽  
G. Kirsch ◽  
J.C. Wilhelm ◽  
...  
Keyword(s):  
Pyrolysis Products
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