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.

In-Situ Preparation of TiC/Al2O3, TiN/Al2O3 and TiN/AIN Composites From Alkoxide-Derived Precursors

1991 ◽  
Vol 249 ◽  
Author(s):  
Zhiping Jiang ◽  
Wendell E. Rhine
Keyword(s):  
Furfuryl Alcohol ◽  
Hydrolysis Product ◽  
Pyrolysis Products ◽  
Polymeric Precursors ◽  
In Situ Preparation ◽  
Elemental Analyses ◽  
Fine Microstructure

ABSTRACTThe reaction between furfuryl alcohol (FuOH) and the hydrolysis product of a mixture of Ti(O-n-Bu)4 and Al(O-sec-Bu)3 (AI:Ti=1:1) resulted in the formation of soluble polymeric solids. Pyrolysis of these polymers in argon yielded TiC/A2O3 composite at 1250 °C. When these polymers were pyrolyzed in ammonia, TiN/AI2O3 or TiN/AIN composite was formed. All these composites showed fine microstructure and excellent homogeneity. Furthermore, the structure and pyrolysis chemistry of these polymeric precursors as well as the microstructure of the pyrolysis products were studied by means of FTIR, TGA, XRD, SEM, TEM, STEM, Auger, elemental analyses etc.

Preparation and Characterization of Y3Al5O12 (YAG) from An Alkoxide-Derived Polymer

1992 ◽  
Vol 286 ◽  
Author(s):  
Zhiping Jiang ◽  
Wendell E. Rhine
Keyword(s):  
Infrared Spectroscopy ◽  
Yttrium Aluminum Garnet ◽  
Polymeric Materials ◽  
Pyrolysis Products ◽  
Elemental Analyses ◽  
Yttrium Aluminum ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis

ABSTRACTThe controlled hydrolysis of Al(O-sec-Bu)3 and Y(O-iso-Pr)3 or the reaction of Y(OOCCH)3 with partially hydrolyzed Al(O-sec-Bu)3 [AlO0.75(O-sec-Bu)1.5] resulted in the formation of soluble polymeric materials. Pyrolysis of these materials under a flow of oxygen led to the formation of yttrium aluminum garnet (YAG) at 650-1500°C. YAG was the only crystalline phase observed during pyrolysis, and the Al/Y ratio of the pyrolysis products and the starting material was identical. However, infrared spectroscopy indicated that carbonate groups and entrained CO2 existed in the products at temperatures up to 1250°C. The pyrolysis chemistry of the precursors and the microstructure of the products were studied by FT-IR, TGA, XRD, SEM and elemental analyses.

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.

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

scholarly journals Microwave-assisted synthesis and characterization of some optically active poly(ester-imide) thermoplastic elastomers

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeed Zahmatkesh ◽  
Abdol Reza Hajipour
Keyword(s):  
Thermal Analyses ◽  
Specific Rotation ◽  
Thermoplastic Elastomers ◽  
Optically Active ◽  
Microwave Assisted Synthesis ◽  
H Nmr ◽  
Microwave Assisted ◽  
Diacid Chloride ◽  
Elemental Analyses

AbstractPyromellitic dianhydride (1) was reacted with L-leucine (2) to result in [N,N'-(pyromellitoyl)-bis-L-leucine diacid] (3). This compound (3) was converted to N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacid chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic bisphenols furnish a series of new PEIs and Co-PEIs in a laboratory microwave oven (Milestone). The resulting polymers and copolymers have inherent viscosities in the range of 0.31- 0.53 dl g-1. These polymers are optically active, thermally stable and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc and sulfuric acid. All of the above polymers were fully characterized by IR spectroscopy, 1H NMR spectroscopy, elemental analyses, specific rotation and thermal analyses. Some structural characterizations and physical properties of these optically active PEIs and Co-PEIs are reported.

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

scholarly journals Synthesis characterization of Cr(III), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of 2,12-dimethyl-3-13-di-n-propyl-l,4,ll,14-tetraazacycloeicosa-1,13,l1,13-tetraene

2002 ◽  
Vol 67 (12) ◽  
pp. 825-832 ◽  
Author(s):  
Raghu Prasad ◽  
Mala Mathur
Keyword(s):  
Metal Ions ◽  
Metal Complexes ◽  
Electronic Spectra ◽  
Magnetic Measurements ◽  
Elemental Analyses

Metal complexes of a 20-membered tetraazamacrocycle 2,12-dimethyl-3,13-di-n-propyl 1,4,11,14-tetraazacycloeicosa-1,3,11,13-tetraene(L) of the type [MLX2]X(M=Cr(III), Fe(III); X=NO3)[CoLNO3]NO3, [NiL(NO3)2], [CuL]Cl2 and [ZnLCl2]have been prepared by 2+2 cyclocondensation of 2,3-hexanedione with 1,6-diaminohexane in the presence of metal ions as templates. These complexes were characterized by elemental analyses, conductances, IR and electronic spectra and magnetic measurements.

scholarly journals Characterization of selected pyrolysis products of diseased orange wood

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 7118-7126
Author(s):  
Carolina Kravetz ◽  
Carlos Leca ◽  
José Otávio Brito ◽  
Daniel Saloni ◽  
David C. Tilotta
Keyword(s):  
Value Added ◽  
Chemical Compounds ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Products ◽  
Bio Oil ◽  
Potential Applications ◽  
Domestic Use ◽  
Immediate Analysis ◽  
Orange Trees

Orange trees in Brazil are often burned as a means of eradication when they become infected with Huanglongbing disease. Rather than destroying them, which is a low-value proposition, one potential option is to utilize the biomass through pyrolysis. In this preliminary work, orange trees (Citrus sinensis) otherwise selected for purging, were sampled and pyrolyzed at 500 °C, and the charcoal and bio-oil were evaluated for potential value-added use. The results showed that the pyrolysis process resulted in 26.3% charcoal, 57.6% bio-oil, and 16.0% non-condensable gases. Qualitative analysis of the bio-oil by gas chromatography/mass spectrometry found 178 chemical compounds; however, only 25% of those compounds could be reliably identified. Potential applications of the compounds identified in the bio-oil were determined by examining the published literature, and it was found that at least 73% of them showed promise. Finally, initial studies on the immediate analysis of the pyrolysis charcoal showed that it potentially meets the standards set forth for Brazilian domestic use.

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