Tribiological behavior of modified phenolic resin composites for braking applications

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fikrat Yusubov
Keyword(s):  
Thermal Properties ◽  
Phenolic Resin ◽  
Degradation Mechanism ◽  
Mechanical And Thermal Properties ◽  
Content Type ◽  
Dry Conditions ◽  
Powder Metallurgy Methods ◽  
Thermal Stability Of

Purpose The purpose of this paper is to investigate the influence of binder effect on tribological behavior of brake friction composite materials: a case study of phenolic resin modified by N-Methylaniline. Design/methodology/approach Four different friction materials have been fabricated by varying modified phenolic resin content. The samples were prepared by the conventional powder metallurgy methods following ball milling, mixing, pre-forming, hot pressing and post-curing processes. Thermogravimetric analysis was used to determination of the degradation mechanism of organic components and study of thermal stability of the samples. A friction test was carried out in dry conditions using a vertical tribometer. Analysis of worn surfaces was performed using a scanning electron microscope. Findings The experimental results revealed that the sample containing 25 Wt.% phenolic resin has good mechanical and thermal properties with stable friction characteristics. Originality/value This paper presents the effect of N-methylaniline modified phenolic resin on friction composites to improve tribological performance by its thermal properties.

Thermal behavior of N-Methylaniline modified phenolic friction composites

2021 ◽  
pp. 096739112110207
Author(s):  
Yusubov Fikrat Fakhraddin
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Composite Materials ◽  
Phenolic Resin ◽  
Degradation Mechanism ◽  
Thermal Characteristics ◽  
Friction Materials ◽  
Binder Material ◽  
Thermal Stability Of ◽  
Decomposition Properties

This article discusses observations on thermal stability, decomposition properties and degradation of organic components of friction composite materials fabricated by powder metallurgy techniques. N-Methylaniline modified phenolic resin used as a binder material in the preparation of composite materials. Thermogravimetry method was used to study the thermal properties of the samples. The experiments were performed on a TGA Q50 (TA Instrument) in an oxygen atmosphere. In order to better assess the thermal characteristics of the composites, the analyses were carried out by separating thermographs into three parts according to the degradation mechanism. The obtained results helped to assess the thermal stability of the friction materials. The degradation of phenolic resin was observed in the temperature range of 312–362°C. It was found that barite and copper-graphite particles improve the thermal characteristics of the samples.

Mechanical and thermal characterization of grafted PP-NCC nanocomposites

2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik
Keyword(s):  
Thermal Properties ◽  
Interfacial Adhesion ◽  
Thermal Characterization ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Twin Screw ◽  
Thermal Stability Of

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.

Verifying the sustainability factors of mega transportation infrastructure: Sydney Metro’s commissioning through the “significance matrix” methodology

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Koorosh Gharehbaghi ◽  
Kerry McManus ◽  
Maged Georgy ◽  
Ken Farnes ◽  
Francesca Pagliara ◽  
...  
Keyword(s):  
Best Practice ◽  
Transportation Infrastructure ◽  
Content Type ◽  
Ecological Zones ◽  
Key Stakeholders ◽  
Comprehensive Determination ◽  
Transportation Infrastructures ◽  
Sustainability Challenges

Purpose Through the significance matrix, this paper aims to investigate and explore the main sustainability factors of mega transportation infrastructure projects. Sydney’s Metro mega transportation infrastructure is used as a case study. Sydney’s Metro was selected because of its sustainability challenges faced because of the areas’ diverse ecological zones. Sydney’s Metro is thus examined as the basis of best practice for the determination of the sustainability factors of transportation infrastructures. Design/methodology/approach Using the significance matrix as a methodology, this research evaluates the environmental impact assessment and environmental assessment processes, to alleviate the problems of the mega transportation infrastructure. Findings This research found that a more comprehensive determination is needed to further analyse the sustainability factors of mega transportation infrastructures, use of a significance matrix would further assess the environmental complexities of mega transportation infrastructures and the sustainability factors of mega transportation infrastructures should include a nonlinear and asymmetrical scheme highlighting its components and carefully outlining its integration and consolidation. Originality/value Although there is concurrent research into sustainability factors of mega transportation, this paper undertakes a new methodology for such infrastructure. While the significance matrix is not a new concept, it has never been used specifically for mega transportation infrastructure. Subsequently, using the significance matrix as a methodology, this research undertakes such environmental analysis and assessment and thus produces a qualitative risk analysis matrix. The findings from this research will ultimately assist the key stakeholders of mega transportation infrastructures to better plan, monitor and support similar projects.

Morphology, Mechanical and Thermal Properties of Poly(Lactic Acid)/Propylene-Ethylene Copolymer/Cellulose Composites

2019 ◽  
Vol 972 ◽  
pp. 172-177
Author(s):  
Sirirat Wacharawichanant ◽  
Patteera Opasakornwong ◽  
Ratchadakorn Poohoi ◽  
Manop Phankokkruad
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Tensile Stress ◽  
Cellulose Fibers ◽  
Phase Morphology ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Ethylene Copolymer ◽  
Thermal Stability Of

This work studied the effects of various types of cellulose fibers on the morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) (90/10 w/w) blends. The PLA/PEC blends before and after adding cellulose fibers were prepared by melt blending method in the internal mixer and molded by compression method. The morphological analysis observed that the presence of cellulose in PLA did not change the phase morphology of PLA, and PLA/cellulose composite surfaces were observed the cellulose fibers inserted in PLA matrix and fiber pull-out. The phase morphology of PLA/PEC blends was changed from brittle fracture to ductile fracture behavior and showed the phase separation between PLA and PEC phases. The presence of celluloses did not improve the compatibility between PLA and PEC phases. The tensile stress and strain curves found that the tensile stress of PLA was the highest value. The addition of all celluloses increased Young’s modulus of PLA. The PEC presence increased the tensile strain of PLA over two times when compared with neat PLA and PLA was toughened by PEC. The incorporation of cellulose fibers in PLA/PEC blends could improve Young’s modulus, tensile strength, and stress at break of the blends. The thermal stability showed that the degradation temperatures of all types of cellulose were less than the degradation temperatures of PLA. Thus, the incorporation of cellulose in PLA could not enhance the thermal stability of PLA composites and PLA/PEC composites. The degradation temperature of PEC was the highest value, but it could not improve the thermal stability of PLA. The incorporation of cellulose fibers had no effect on the melting temperature of the PLA blend and composites.

scholarly journals Investigation on the modification to solvent-containing two-component polyurethane coating by carbon nanotubes

2015 ◽  
Vol 44 (5) ◽  
pp. 300-305 ◽  
Author(s):  
X. Jiang ◽  
L. Lin ◽  
X. Bai ◽  
S. Wang ◽  
C. Wang
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Properties ◽  
Composite Coating ◽  
Acid Treatment ◽  
Mechanical And Thermal Properties ◽  
Colour Properties ◽  
Content Type ◽  
Two Component ◽  
Appearance Properties

Purpose – The purpose of this paper is to investigate the effects of carbon nanotubes (CNTs) on the mechanical, thermal and colour properties of solvent-containing two-component polyurethane (PU) coating. Design/methodology/approach – Fourier transform infrared spectroscopy and observation of dispersion stability were used to assess the effects of acid treatment on CNTs. The CNTs and PU composite coating was synthesised by in situ polymerisation and bending polymerisation, and the mechanical, thermal and colour appearance properties of coating were characterised. Findings – It was found that desirable modifications to CNTs occurred after acid treatment; thus, mainly carboxylic acid groups were introduced onto the surface of CNTs. And the acid-treated CNTs could improve the mechanical and thermal properties of PU coating, and the properties of composite coating was improved more successfully by in situ polymerisation than by blending polymerisation. Practical implications – The investigation established a method to synthesise CNTs and PU composite coating. The mechanical and thermal properties of PU coating could be improved by the inclusion of CNTs. Originality/value – This study established a method to synthesise CNTs and PU composite coating by in situ polymerisation and blending polymerisation; the effects of CNTs on modifying mechanical, thermal and colour properties of PU coating were investigated and compared in detail.

Researching ethnicity in the Pacific region

2014 ◽  
Vol 26 (3) ◽  
pp. 302-323 ◽  
Author(s):  
Rachel F. Baskerville ◽  
Katharine Wynn-Williams ◽  
Elaine Evans ◽  
Shirley Gillett
Keyword(s):  
Financial Reporting ◽  
First Language ◽  
Accounting Education ◽  
Pacific Region ◽  
Content Type ◽  
Learning And Teaching ◽  
Accounting Research ◽  
The Pacific

Purpose – The purpose of this paper is to examine how the construct of ethnicity can best be determined for empirical analysis in accounting research, particularly in the Pacific region. Design/methodology/approach – This paper reviews relevant sociological and accounting literature. In addition, it presents the results of a case study where “first language” was used as a proxy for ethnicity. Findings – The results of the literature review present six different research approaches towards determining ethnicity. Furthermore, it is found that “first language” was a justifiable determinant of ethnicity in an accounting education study. Research limitations/implications – The determination of reliable and valid proxies for ethnicity in accounting research is important for researchers, including those whose objective is to associate ethnicity with learning and teaching outcomes, accounting and financial reporting activities or behaviours. Originality/value – In the context of accounting research, the value of this study is its challenge to the notions that culture and ethnicity are not only homogenous but interchangeable and to offer a reflection on how ethnicity can be determined.

scholarly journals Determination of the Mechanical and Thermal Properties, and Impact Sensitivity of Pressed HMX-based PBX

2019 ◽  
Vol 16 (2) ◽  
pp. 299-315
Author(s):  
Yuxiang Li ◽  
Peng Wu ◽  
Cheng Hua ◽  
Jun Wang ◽  
Bing Huang ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Impact Sensitivity ◽  
Mechanical And Thermal Properties

On Mechanical and Thermal Properties of Epoxy/Graphene Nanocomposites

2018 ◽  
Vol 22 ◽  
pp. 23-33 ◽  
Author(s):  
Seenaa I. Hussein
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Impact Strength ◽  
Mechanical And Thermal Properties ◽  
Graphene Nanocomposites ◽  
Graphene Composite ◽  
Efficiency Increase ◽  
Graphene Content ◽  
The Impact ◽  
Thermal Stability Of

In this research, we have prepared epoxy/graphene nanocomposites (graphene content: 1, 3, 5, 7, and 9 wt%) to investigate some mechanical (impact strength, hardness, and Brazilian tests) and thermal properties (thermal conductivity and thermogravimetric analysis). Our results show that the impact strength, hardness, and compression strength values increased to 5.04 kJ/m2, 79.8, and 27.85 MPa, respectively, as increasing graphene content up to 5 wt% and then decreased for further increasing of the graphene content. The observed reduction in the hardness could be attributed to the samples brittleness. On the other hand, the thermal conductivity increased with increasing the graphene content because of the high thermal conductivity of graphene and thus the efficiency increase with increasing of graphene content. In addition, the thermal stability of epoxy/graphene composite increase compared with pure epoxy resin, while the activation energy for samples consists of 9 wt% graphene greater than those containing 1 wt% graphene.

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