Interfacial characteristics between mineral fillers and phenolic resin in friction materials

2020 ◽  
Vol 10 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Xiaoguang Zhao ◽  
Jing Ouyang ◽  
Qi Tan ◽  
Xiumin Tan ◽  
Huaming Yang
Keyword(s):  
Thermal Conductivity ◽  
Phenolic Resin ◽  
Special Functions ◽  
Structural Characteristics ◽  
Scanning Calorimetry ◽  
Friction Materials ◽  
Brake Application ◽  
Reducing Costs ◽  
Mineral Fillers ◽  
Interfacial Characteristics

Mineral fillers are indispensable constituent part of friction materials, which are capable of improving and stabilizing coefficient of friction, decreasing wear, enhancing thermal conductivity and reducing costs of friction materials, in addition, decreasing the noise in brake application. Based on their roles in the friction materials, mineral fillers are classified into abrasives, lubricants, functional fillers, and space fillers. Herein, four typical commercial mineral fillers, namely quartz, graphite, expanded vermiculite, and barite were studied for revealing their effects on the performance of friction materials. The composition, thermal stability, structural characteristics such as surface area, pore volume, and distribution of the pore size, and thermal conductivity of these mineral fillers were researched mainly by X-ray diffraction (XRD), differential scanning calorimetry and thermogravimetry (DSC-TG), N2 adsorption–desorption isotherms, and thermal conductivity tester. Moreover, in order to illustrate the interfacial characteristics of mineral-based in friction materials, four ideal brake pads only consisting of mineral filler, BaSO4 and phenolic resin were prepared. Microstructure and combination of mineral fillers and phenolic resin were investigated by scanning electron microscopy (SEM), polarizing microscope, and Fourier transformation infrared spectroscopy (FTIR). The results showed that different types of material fillers had special functions for friction materials, and they combined with phenolic resin mainly in a physical way.

scholarly journals Improved high-temperature damping performance of nitrile-butadiene rubber/phenolic resin composites by introducing different hindered amine molecules

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 482-490
Author(s):  
Meng Song ◽  
Xiulin Yue ◽  
Xiujuan Wang ◽  
Mengjie Huang ◽  
Mingxing Ma ◽  
...  
Keyword(s):  
High Temperature ◽  
Phenolic Resin ◽  
Thermomechanical Analysis ◽  
Butadiene Rubber ◽  
Scanning Calorimetry ◽  
Nitrile Butadiene Rubber ◽  
Theoretical Support ◽  
Higher Temperature ◽  
Damping Materials ◽  
Hybrid Damping

AbstractBy introducing hindered amine GW-622 or GW-944 into nitrile-butadiene rubber/phenolic resin (NBR/PR, abbreviated as NBPR) matrix, we have prepared different hindered amine/NBR/PR ternary hybrid damping materials with high-temperature damping performance, respectively. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and dynamic thermomechanical analysis (DMA) were used to research the microstructure, compatibility, and damping properties of the hindered amine/NBPR composites. FTIR results indicate that hydrogen bonds are formed between the hindered amine and the NBPR matrix. Both DSC and SEM results show that hindered amine has partial compatibility with the NBPR matrix. DMA results show that two loss peaks appear in the hindered amine/NBPR composite. Thereby, the composites show better damping performance at a higher temperature, and the temperature domain of high-temperature damping becomes wider with the increase in the addition of hindered amine. This study provides a theoretical support for the preparation of high-temperature damping materials.

A study on the kinetics and thermal properties of polystyrene/diatomite nanocomposites prepared via in situ ATRP

2018 ◽  
Vol 33 (2) ◽  
pp. 180-197 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli
Keyword(s):  
Molecular Weight ◽  
In Situ Polymerization ◽  
Structural Characteristics ◽  
Nitrogen Adsorption ◽  
Linear Increase ◽  
Size Exclusion ◽  
Scanning Calorimetry ◽  
Morphological Studies ◽  
Exclusion Chromatography

Pristine mesoporous diatomite was employed to prepare polystyrene/diatomite composites. Diatomite platelets were used for in situ polymerization of styrene by atom transfer radical polymerization to synthesize tailor-made polystyrene nanocomposites. X-Ray fluorescence spectrometer analysis and thermogravimetric analysis (TGA) were employed for evaluating some inherent properties of pristine diatomite platelets. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite platelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Linear increase of ln ( M0/M) with time for all the samples shows that polymerization proceeds in a living manner. Addition of 3 wt% pristine mesoporous diatomite leads to an increase of conversion from 72% to 89%. Molecular weight of polystyrene chains increases from 11,326 g mol−1 to 14134 g mol−1 with the addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.13 to 1.38. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 81.9°C to 87.1°C by adding 3 wt% of mesoporous diatomite platelets.

Preparation and Properties of SiC/Phenolic Resin for the Heat of LED

2016 ◽  
Vol 848 ◽  
pp. 454-459
Author(s):  
Cong Wu ◽  
Kang Zhao ◽  
Yu Fei Tang ◽  
Ji Yuan Ma
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Powder Metallurgy ◽  
Phenolic Resin ◽  
Bending Strength ◽  
Experimental Results ◽  
Low Thermal Conductivity ◽  
Industry Standard ◽  
Insulation Performance

In order to solve the problem that low thermal conductivity of the plastics for the heat of LED, SiC/Phenolic resin for the heat of LED were fabricated combining powder metallurgy. The effects of particles diameters, content and adding nanoparticles on thermal conductivity of the fabricated composites were investigated, the mechanical properties were also characterized. The experimental results showed that the materials were obtained, and the insulation performance of the fabricated SiC/Phenolic resin was higher than the industry standard one, the thermal conductivity reached 4.1W/(m·k)-1. And the bending strength of the fabricated composites was up to 68.11MPa. The problem of low thermal conductivity of the material is expected to be solved. In addition, it is meaningful for improving LED life.

scholarly journals Effects of pressure and temperature on thermal contact resistance between different materials

2015 ◽  
Vol 19 (4) ◽  
pp. 1369-1372 ◽  
Author(s):  
Zhe Zhao ◽  
Hai-Ming Huang ◽  
Qing Wang ◽  
Song Ji
Keyword(s):  
Thermal Conductivity ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Experimental Approach ◽  
Phenolic Resin ◽  
Thermal Conductivity Coefficient ◽  
Thermal Contact ◽  
Carbon Composites ◽  
Interfacial Temperature ◽  
Temperature And Pressure

To explore whether pressure and temperature can affect thermal contact resistance, we have proposed a new experimental approach for measurement of the thermal contact resistance. Taking the thermal contact resistance between phenolic resin and carbon-carbon composites, cuprum, and aluminum as the examples, the influence of the thermal contact resistance between specimens under pressure is tested by experiment. Two groups of experiments are performed and then an analysis on influencing factors of the thermal contact resistance is presented in this paper. The experimental results reveal that the thermal contact resistance depends not only on the thermal conductivity coefficient of materials, but on the interfacial temperature and pressure. Furthermore, the thermal contact resistance between cuprum and aluminum is more sensitive to pressure and temperature than that between phenolic resin and carbon-carbon composites.

The Synthesis and Characterization of the Graphene Oxide Covalent Modified Phenolic Resin Nanocomposites

2011 ◽  
Vol 327 ◽  
pp. 115-119 ◽  
Author(s):  
Duo Wang ◽  
Jie Gao ◽  
Wei Fang Xu ◽  
Feng Bao ◽  
Rui Ma ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Phenolic Resin ◽  
Synthesis And Characterization ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Hummers Method ◽  
Modified Hummers Method ◽  
Thermal Stability Of

Graphene oxide (GO) was made by a modified Hummers method. Graphene oxide modified phenolic resin nanocomposites (GO/PF) were prepared by Steglich esterification, catalyzed by dicyclohexyl carbodiimide and 4-dimethylaminopyridine. The composites were characterized by Fourier transform infrared spectrometry, differential scanning calorimetry, X-ray powder diffraction, and scanning electron microscopy. The result revealed that the graphene oxide was absolutely exfoliated and covalent linked GO/PF composite was obtained. The thermal stability of PF is remarkably improved by modification with GO.

Design and development of submerged arc welding fluxes using TiO2-SiO2-CaO and SiO2-CaO-Al2O3 flux system

2018 ◽  
Vol 233 (4) ◽  
pp. 739-762 ◽  
Author(s):  
Lochan Sharma ◽  
Rahul Chhibber
Keyword(s):  
Thermal Conductivity ◽  
Differential Scanning Calorimetry ◽  
Binary Mixture ◽  
Arc Welding ◽  
Ternary Mixture ◽  
Submerged Arc Welding ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Welding Fluxes ◽  
Submerged Arc

Submerged arc welding is widely used in pipeline manufacturing due to higher efficiency as compared to the other welding processes. In present study, TiO2-SiO2-CaO and SiO2-CaO-Al2O3–based submerged arc welding fluxes were developed for joining of linepipe steel. Twenty-one fluxes were formulated based on mixture design methodology. Fluxes were analysed using X-ray florescence (XRF), thermogravimetric, differential-scanning calorimetry, Hot-disc and X-ray diffraction (XRD) techniques. The structural behaviour of rutile basic fluxes were analysed using Fourier transformed infrared spectroscopy (FTIR). Thermo-gravimetric analysis and differential scanning calorimetry were performed from 25 ℃ to 900 ℃ in order to determine the thermal stability and change in enthalpy of fluxes. Thermal conductivity, thermal diffusivity and specific heat of each flux were evaluated by hot disc technique. The density and grain fineness number for flux particles was evaluated at room temperature. Multi objective optimisation was performed to derive the optimised flux formulations. Individual effect of all the mixture constituents is rarely observed on the physicochemical properties of fluxes as compared to the binary and ternary mixture effects. The binary compositions significantly affect the density. TiO2-CaO is the most effective binary mixture which has increasing effect on density while all remaining binary mixture constituents have decreasing effect. The weight loss of fluxes observed during thermogravimetric analysis is affected by binary and ternary mixture constituents. Both binary and ternary flux mixtures affect change in enthalpy observed during differential scanning calorimetry. SiO2.Al2O3 is the only most effective binary mixture constituent of flux having increasing effect on thermal conductivity. Binary mixture constituents TiO2.CaF2, SiO2.Al2O3 and CaO.Al2O3 are the most effective and having synergistic effect on thermal diffusivity.

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