scholarly journals Thermal Decomposition and Ceramifying Process of Ceramifiable Silicone Rubber Composite with Hydrated Zinc Borate

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1591
Author(s):  
Jiuqiang Song ◽  
Zhixiong Huang ◽  
Yan Qin ◽  
Xinyi Li
Keyword(s):  
Thermal Decomposition ◽  
Compressive Strength ◽  
Network Structure ◽  
Silicone Rubber ◽  
Bending Strength ◽  
Linear Shrinkage ◽  
Decomposition Temperature ◽  
Zinc Borate ◽  
Air Atmosphere ◽  
Rubber Composite

The ceramifiable silicone rubber composite was prepared using hydrated zinc borate and kaolin as ceramifiable fillers. Effects of the hydrated zinc borate content and the combustion temperature on the properties of the ceramifiable silicone rubber composite were investigated. Thermal decomposition and ceramifying processes of the composite in a muffle furnace under air were also studied. The results showed that the density and the hardness of the composites increased as the content of the hydrated zinc borate increased from 0 to 30 phr. The tensile strength and elongation at break decreased. In addition, hydrated zinc borate decreased the decomposition temperature of the composite, whereas the residue weight under air atmosphere was increased. In the process of decomposition and oxidation of the ceramifiable silicone rubber composite in air, B2O3 was generated by the decomposition of zinc borate and participated in the formation of the residue network structure, which decreased the temperature of the ceramifying transition. The new phases, zinc aluminate (ZnO·Al2O3) and aluminum-rich mullite (9Al2O3·2SiO2), appeared after high-temperature thermochemical reactions. Microscopy images revealed that different structures were formed at different temperatures. The network structure of the ceramic residue became increasingly compact, and the compressive strength increased from 0.31 to 1.82 MPa with the increase of temperature from 800 to 1400 °C, which had a better protective effect on heat transfer and mass loss. The weight loss and the linear shrinkage of the ceramic residue was 37.6% and 21.9%, respectively, with the 30 phr content of hydrated zinc borate. The bending strength was improved from 0.11 to 11.58 MPa, and the compressive strength also increased from 0.03 to 1.14 MPa.

Studies on the Properties of Epoxy Resins Modified with Novel Liquid Crystalline Polyurethane

2010 ◽  
Vol 150-151 ◽  
pp. 727-731 ◽  
Author(s):  
Zhi Yi Huang ◽  
Shao Rong Lu ◽  
Zhi You Yang ◽  
Chun He Yu ◽  
Dong Guo
Keyword(s):  
Thermal Decomposition ◽  
Tensile Strength ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Liquid Crystalline ◽  
Bending Strength ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
The Impact ◽  
Unmodified Epoxy

Liquid crystal polyurethane (LCPBI) containing biphenylnate and imide units was synthesized and characterized and used to modify the conventional epoxy resin (E-51). Experimental results revealed that the impact strength of the epoxy resin modified with LCPBI was 2.5 times higher than that of unmodified epoxy resin, and the tensile strength as well as the bending strength was also improved. The thermal decomposition temperature of modified systems was also 15-20oC higher than that of the unmodified system, and the fracture structures of the blends was investigated by SEM.

scholarly journals Preparation of Bamboo-Like Carbon Nanotube Loaded Piezoresistive Polyurethane-Silicone Rubber Composite

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2144
Author(s):  
Mohammed Nabeel ◽  
Miklós Varga ◽  
László Kuzsela ◽  
Ádám Filep ◽  
Béla Fiser ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Silicone Rubber ◽  
Dip Coating ◽  
Nitrogen Doped ◽  
Novel Technology ◽  
Pu Foam ◽  
Rubber Composite ◽  
Finger Touch ◽  
Human Monitoring ◽  
Strength And Durability

In this study, a novel technology is reported to prepare a piezoresistive polyurethane-silicone rubber nanocomposite. Polyurethane (PU) foam was loaded with a nitrogen-doped bamboo-shaped carbon nanotube (N-BCNT) by using dip-coating, and then, impregnated with silicone rubber. PU was used as a supporting substrate for N-BCNT, while silicone rubber was applied to fill the pores of the foam to improve recoverability, compressive strength, and durability. The composite displays good electrical conductivity, short response time, and excellent repeatability. The resistance was reduced when the amount of N-BCNT (0.43 wt %) was increased due to the expanded conductive path for electron transport. The piezoresistive composite has been successfully tested in many applications, such as human monitoring and finger touch detection.

scholarly journals Isothermal Kinetic Analysis of the Thermal Decomposition of Wood Chips from an Apple Tree

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 195
Author(s):  
Ivan Vitázek ◽  
Martin Šotnar ◽  
Stella Hrehová ◽  
Kristína Darnadyová ◽  
Jan Mareček
Keyword(s):  
Thermal Decomposition ◽  
Apple Tree ◽  
Combustion Process ◽  
Reaction Model ◽  
Wood Chips ◽  
Small Scale ◽  
Exponential Factor ◽  
Air Atmosphere ◽  
First Order Chemical Reaction ◽  
Isothermal Kinetic

The thermal decomposition of wood chips from an apple tree is studied in a static air atmosphere under isothermal conditions. Based on the thermogravimetric analysis, the values of the apparent activation energy and pre-exponential factor are 34 ± 3 kJ mol−1 and 391 ± 2 min−1, respectively. These results have also shown that this process can be described by the rate of the first-order chemical reaction. This reaction model is valid only for a temperature range of 250–290 °C, mainly due to the lignin decomposition. The obtained results are used for kinetic prediction, which is compared with the measurement. The results show that the reaction is slower at higher values of degree of conversion, which is caused by the influence of the experimental condition. Nevertheless, the obtained kinetic parameters could be used for the optimization of the combustion process of wood chips in small-scale biomass boilers.

scholarly journals Production of ceramics from coal fly ash

2012 ◽  
Vol 18 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Biljana Angjusheva ◽  
Emilija Fidancevska ◽  
Vojo Jovanov
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Solid State ◽  
Liquid Phase ◽  
Bending Strength ◽  
Coal Fly Ash ◽  
Liquid Phase Sintering ◽  
Heating Rates ◽  
Republic Of Macedonia ◽  
The Subject

Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa) and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min). Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al)(Si,Al)2O6] was formed. Ceramics with optimal properties (porosity 2.96?0.5%, bending strength - 47.01?2 MPa, compressive strength - 170 ?5 MPa) was produced at 1100?C using the heating rate of 10?C/min.

Kinetic Modeling of Coal Thermal Decomposition under Air Atmosphere

2016 ◽  
Vol 30 (6) ◽  
pp. 5158-5166 ◽  
Author(s):  
Peng Chen ◽  
Lang Zhang ◽  
Kai Huang
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Modeling ◽  
Air Atmosphere

scholarly journals The effect of microstructural features on the mechanical properties of LZSA glass-ceramic matrix composites

Cerâmica ◽  
2013 ◽  
Vol 59 (351) ◽  
pp. 351-359 ◽  
Author(s):  
F. M. Bertan ◽  
A. P. Novaes de Oliveira ◽  
O. R. K. Montedo ◽  
D. Hotza ◽  
C. R. Rambo
Keyword(s):  
Glass Ceramic ◽  
Bending Strength ◽  
Chemical Properties ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Linear Shrinkage ◽  
Matrix Composites ◽  
Particulate Reinforced ◽  
And Chemical Properties

This work reports on the characterization of ZrSiO4 particulate-reinforced Li2O-ZrO2-SiO2-Al2O3 (LZSA) glass-ceramic matrix composites. The typical physical/mechanical and chemical properties of the glass batches and the composites were measured. A composition with 60 wt.% ZrSiO4 was preliminarily selected because it demonstrated the highest values of bending strength (190 MPa) and deep abrasion resistance (51 mm³). To this same composition was given a 7 wt.% bentonite addition in order to obtain plasticity behavior suitable for extrusion. The sintered samples (1150 ºC for 10 min) presented a thermal linear shrinkage of 14% and bending strength values of 220 MPa.

scholarly journals Structures and Properties of Self - crosslinking Silicone Resin

2018 ◽  
Vol 38 ◽  
pp. 02019
Author(s):  
Yong-xin Zhao ◽  
Ying-qiang Zhang
Keyword(s):  
Thermal Decomposition ◽  
Raw Materials ◽  
Decomposition Temperature ◽  
Light Transmittance ◽  
Silicone Resin ◽  
Structures And Properties ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Good Heat Resistance ◽  
Good Heat

Highly transparent silicone resin with self-crosslinking structure was prepared using phenyltrimethoxysilane, diphenyldimethoxysilane, 1,3,5,7-cyclotetra(methyl siloxane) and bisvinyltetramethyldisiloxane as main raw materials. The structure of silicone resin was determined by Fourier Transform Infrared Spectroscopy (FT-IR). The light transmittance was measured by UV-Vis spectroscopy. Thermogravimetric analysis (TGA) was used to study the thermal decomposition process. The microstructure of cured self-crosslinking silicone resin is more uniform, resulting in better light transmittance up to 100% in the range of 400nm ~ 800nm. The cured has relatively good heat resistance, the initial thermal decomposition temperature of the cured could be up to 315.8 °C. SEM observations show that the self-crosslinking silicone has a uniform, textured structure, higher transparency compared with the existing condensation silicone material, and can be used as advanced architectural translucent materials and optics packaging materials.

Size-dependent thermal decomposition and kinetics of ultrafine alkali metal styphnates

RSC Advances ◽  
2014 ◽  
Vol 4 (74) ◽  
pp. 39463-39471 ◽  
Author(s):  
Rui Liu ◽  
Wenyuan Zhao ◽  
Tonglai Zhang ◽  
Li Yang ◽  
Zunning Zhou ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Alkali Metal ◽  
Decomposition Temperature ◽  
Size Dependent ◽  
Kinetics Of

The styphnate of smaller size possesses lower decomposition temperature and higher reactivity.

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