Enhancement of thermal stability and chemical reactivity of phenolic resin ameliorated by nanoSiO2

2017 ◽  
Vol 35 (1) ◽  
pp. 298-302 ◽  
Author(s):  
Yajun Guo ◽  
Lihong Hu ◽  
Puyou Jia ◽  
Baofang Zhang ◽  
Yonghong Zhou
Keyword(s):  
Thermal Stability ◽  
Phenolic Resin ◽  
Chemical Reactivity

An Addition-Curable Hybrid Phenolic Resin Containing Silicon and Boron with Improved Thermal Stability

2021 ◽  
pp. 109599
Author(s):  
Youpei Du ◽  
Yu Xia ◽  
Zhenhua Luo ◽  
Wenjie Yuan ◽  
Kongli Xu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phenolic Resin

Self-Assembled Monolayer Coatings on Amorphous Iron and Iron Oxide Nanoparticles:  Thermal Stability and Chemical Reactivity Studies

Langmuir ◽  
1997 ◽  
Vol 13 (23) ◽  
pp. 6151-6158 ◽  
Author(s):  
G. Kataby ◽  
T. Prozorov ◽  
Yu. Koltypin ◽  
H. Cohen ◽  
Chaim N. Sukenik ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Chemical Reactivity ◽  
Oxide Nanoparticles ◽  
Self Assembled Monolayer ◽  
Amorphous Iron ◽  
Self Assembled

Formation of dense silicon carbide by liquid silicon infiltration of carbon with engineered structure

2008 ◽  
Vol 23 (5) ◽  
pp. 1237-1248 ◽  
Author(s):  
Jesse C. Margiotta ◽  
Dajie Zhang ◽  
Dennis C. Nagle ◽  
Caitlin E. Feeser
Keyword(s):  
Silicon Carbide ◽  
Bulk Density ◽  
Phenolic Resin ◽  
Pore Diameter ◽  
Chemical Reactivity ◽  
Liquid Silicon ◽  
Crystalline Cellulose ◽  
Carbon Preform ◽  
Median Pore ◽  
The Ideal

Fully dense and net-shaped silicon carbide monoliths were produced by liquid silicon infiltration of carbon preforms with engineered bulk density, median pore diameter, and chemical reactivity derived from carbonization of crystalline cellulose and phenolic resin blends. The ideal carbon bulk density and minimum median pore diameter for successful formation of fully dense silicon carbide by liquid silicon infiltration are 0.964 g cm−3 and approximately 1 μm. By blending crystalline cellulose and phenolic resin in various mass ratios as carbon precursors, we were able to adjust the bulk density, median pore diameter, and overall chemical reactivity of the carbon preforms produced. The liquid silicon infiltration reactions were performed in a graphite element furnace at temperatures between 1414 and 1900 °C and under argon pressures of 1550, 760, and 0.5 Torr for periods of 10, 15, 30, 60, 120, and 300 min. Examination of the results indicated that the ideal carbon preform was produced from the crystalline cellulose and phenolic resin blend of 6:4 mass ratio. This carbon preform has a bulk density of 0.7910 g cm−3, an actual density of 2.1911 g cm−3, median pore diameter of 1.45 μm, and specific surface area of 644.75 m2 g−1. The ideal liquid silicon infiltration reaction conditions were identified as 1800 °C, 0.5 Torr, and 120 min. The optimum reaction product has a bulk density of 2.9566 g cm−3, greater than 91% of that of pure β–SiC, with a β–SiC volume fraction of approximately 82.5%.

Bio-Crude by Acidic Phenolation and Carbamation for the Preparation of Phenolic Thermosetting Resin and Its Application in Thermoresistant Laminates

2019 ◽  
Vol 17 (4) ◽  
Author(s):  
Huan Wang ◽  
Zhuo Wang ◽  
Penggang Ren ◽  
Mingcun Wang
Keyword(s):  
High Performance ◽  
Phenolic Resin ◽  
Mechanical Test ◽  
Chemical Reactivity ◽  
Cost Effective ◽  
Mechanical Analysis ◽  
Thermosetting Resin ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Mechanical Performances

Abstract Fir sawdust was liquefied in phenol solvent under acidic catalyst at 135, 150 and 165 °C, respectively; after neutralization, bio-crude was obtained where contained oil-like liquid and tiny powder-like residue. The bio-crude was chemically modified with urea at high temperature (e. g. > 130 °C) to form carbamate so as to improve chemical reactivity of bio-crude in phenolic resin synthesis. The carbamate-containing bio-crude was condensed with paraformaldehyde into thermosetting phenolic resin. Finally, this biomass-derived phenolic resin matrixed silica fabric laminates were processed. The uncured and thermally cured bio-based resins were characterized by the techniques of Differential Scanning Calorimetry (DSC), Fourier Transform Infrared spectrum (FT-IR), rheology and Thermogravimetric Analysis (TGA), and the laminates’ structure and mechanical performances were studied using the methods of Scanning Electron Microscopy (SEM), three point bending mechanical test and Dynamic Mechanical Analysis (DMA). The results showed: (1) the chemical reactivity of bio-crude was highly improved by carbamation; (2) biomass-derived thermosetting phenolic resin was thermally curable at 150–250 °C (with two exothermic peaks at 185 °C and 220 °C); (3) the char yield was about 47 %, which was not in apparent relationship with sawdust liquefaction temperatures; (4) flexural strength of silica fabric laminates at room temperature was around 357 MPa (similar with that of conventional phenolic laminate); (5) glass transition temperature of silica fabric laminate was above 270 °C (much higher than Tg of conventional phenolic resin laminate, which is normally at 215 °C). The biomass-derived phenolic resin is expected to be widely used as cost-effective and environment-friendly thermosetting resin in the application of high-performance composites.

Raman spectra of single walled carbon nanotubes at high temperatures: pretreating samples in a nitrogen atmosphere improves their thermal stability in air

2017 ◽  
Vol 19 (10) ◽  
pp. 7215-7227 ◽  
Author(s):  
J. Molina-Duarte ◽  
L. I. Espinosa-Vega ◽  
A. G. Rodríguez ◽  
R. A. Guirado-López
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Raman Spectra ◽  
Temperature Interval ◽  
Theoretical Study ◽  
Chemical Reactivity ◽  
Single Walled Carbon Nanotubes ◽  
Nitrogen Atmosphere ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

We present a combined experimental and theoretical study dedicated to analyzing the structural stability and chemical reactivity of single walled carbon nanotubes (SWCNTs) in the presence of air and nitrogen atmospheres in the temperature interval of 300–1000 K.

Chemical reactivity and thermal stability of nanometric alkali metal hydrides

2006 ◽  
Vol 8 (6) ◽  
pp. 935-942 ◽  
Author(s):  
Yinheng Fan ◽  
Weina Li ◽  
Yunling Zou ◽  
Shijian Liao ◽  
Jie Xu
Keyword(s):  
Thermal Stability ◽  
Alkali Metal ◽  
Chemical Reactivity ◽  
Metal Hydrides ◽  
Thermal Stability Of
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