Miscibility of EPM-EPDM Blends

2003 ◽  
Vol 76 (2) ◽  
pp. 495-506 ◽  
Author(s):  
H. G. Dikland ◽  
M. Van Duin
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Excellent Agreement ◽  
Abrasion Resistance ◽  
Dynamic Properties ◽  
Cost Effective ◽  
Major Influence ◽  
Rule Of Thumb ◽  
Monomer Content ◽  
The Difference

Abstract Blends of elastomers are often used as a basis for compound formulations. For instance, tire tread formulations may contain NR, BR and SBR in order to provide cost-effective products with good mechanical properties, dynamic properties and abrasion resistance. Blends of dissimilar EPDM grades are often used when formulating EPDM compounds. In many cases such EPDM-EPDM blends are used to obtain synergy, i.e. properties of the parent EPDM grades are not averaged, but favorable properties of the blend components are combined or unfavorable properties suppressed. In the present paper the miscibility regime for gum stock EPDM-EPDM blends has been calculated based on elementary thermodynamic considerations. Results of calculations have been validated by experiments, and excellent agreement was found. It was found that the chemical composition of EPDM grades has a major influence on miscibility. It is concluded that, as a rule of thumb, two EPDM grades are thermodynamically miscible if the difference between the combined ethylene and third monomer content is less than 12 % by weight. Based on the results it is possible to understand and to some extent predict the behavior of rubber products based on dissimilar EPDM grades.

HAF/SILICA/NANOCLAY “TERNARY” MASTERBATCH AND HAF/SILICA BINARY MASTERBATCH FROM FRESH NATURAL RUBBER LATEX

2014 ◽  
Vol 87 (2) ◽  
pp. 250-263 ◽  
Author(s):  
Sasidharan Krishnan ◽  
Rosamma Alex ◽  
Thomas Kurian
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Abrasion Resistance ◽  
Dynamic Properties ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
X Ray ◽  
Filler Dispersion

ABSTRACT A process for production of carbon black/silica/nanoclay ternary filler masterbatch from fresh natural rubber (NR) latex was standardized. The fillers, nanoclay, carbon black, and silica were incorporated in fresh NR latex by a modified coagulation process. The latex, mixed with filler dispersions, coagulated immediately on addition of acids. The coagulum containing fillers was dried at 70 °C in an air oven to get the latex filler masterbatch, which was further processed in the conventional way. The masterbatch compounds containing only silica/carbon black showed a higher level of vulcanization as compared with the corresponding dry mixes. The mechanical properties, such as tensile strength, modulus, tear strength, abrasion resistance, and hardness, increased with the proportion of nanoclay in the mixes up to 5 phr, and with a greater amount, the change was only marginal. Lower tan delta values were observed for all of the masterbatches containing nanoclay in the ranges of 3 to 10 phr compared with the control dry mix containing 25/25 carbon black/silica. The improvement in mechanical properties and dynamic properties shown by the masterbatches over the conventional mill-mixed compounds was attributed to factors related to filler dispersion, as evidenced from the data from dispersion analyzer images, X-ray diffractograms, and a higher level of vulcanization.

scholarly journals Mathematical model of the mechanical properties of Ti-alloyed hypoeutectic cast iron for mixer blades

2021 ◽  
pp. 99-110
Author(s):  
Sergei Kharchenko ◽  
Andriy Barsuk ◽  
Nurlana Karimova ◽  
Alexander Nanka ◽  
Yevhen Pelypenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Wear Resistance ◽  
Cast Iron ◽  
Chemical Composition ◽  
Ultimate Strength ◽  
Abrasion Resistance ◽  
Resistance Coefficient ◽  
Regression Equations ◽  
Selection Of

The object of research is hypoeutectic cast iron intended for cast parts operating under abrasive friction conditions. Such parts are mixer blades, the operational properties of which include durability, assessed by abrasion resistance and strength. To give the blades such properties, cast irons, which are materials of the blades, are alloyed with elements that contribute to the formation of carbides of various compositions. The main problem that impedes the targeted selection of materials for mixer blades or finished blades from different materials or different chemical composition is the lack of substantiated selection criteria. If the shipment is carried out only with the provision of data on the chemical composition of the alloy, it is necessary to be able to evaluate the expected mechanical properties, in particular abrasion resistance and strength. Using the methods of regression analysis, a mathematical model has been obtained that includes two regression equations, which allows for a targeted selection of the chemical composition that provides the maximum possible value of mechanical properties – ultimate strength and coefficient of wear resistance. Optimization of the chemical composition, carried out according to this model, made it possible to determine the following chemical composition: C=2.94 %, Ceq=3.3 %, Ti=1.56 %, providing the maximum ultimate strength σb=391 MPa; C=2.78 %, Ceq=3.14 %, Ti=1.61 %, providing a maximum wear resistance coefficient Kwr=12 %. In the case of priority of the strength criterion, the calculated optimal chemical composition makes it possible to reduce the mass-dimensional characteristics of the mixing units of the mixers. A procedure is proposed for using this model to select a batch of blades with the expected best performance properties

scholarly journals Development of an inexpensive functional textile product by applyingaccounting cost benefit analysis

2020 ◽  
Vol 71 (01) ◽  
pp. 17-22
Author(s):  
SOBIA NASEEM ◽  
GAO LEI FU ◽  
MUHAMAD MOHSIN ◽  
MUHAMMAD SOHAIL AUNJAM ◽  
MUHAMMAD ZEESHAN RAFIQ ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Abrasion Resistance ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Cost Effective ◽  
Air Permeability ◽  
Functional Requirements ◽  
Benefit Analysis ◽  
Spun Yarns ◽  
Cut Resistance

This research is to utilize accounting cost benefit analysis for manufacturing of economically cost-effective cut resistantgloves knitted from core spun yarns made up of nylon and polyester with E-glass as core. E-glass has a significantimpact on the cut resistance and abrasion resistance of the gloves. The gloves are knitted by using core spun yarns,and tested for their physical, cut & abrasion resistant properties. Economic characteristics of final product are criticallyobserved and analysed through cost benefit analysis. Results elaborate that Polyester/E-glass hand gloves have spe-cial mechanical properties like Abrasion resistance and Blade cut resistance. Instead, Nylon/E-glass hand gloves havegood air permeability. Cost benefit analysis reveal that the outcomes are comparable to functional requirements withinlow cost.

scholarly journals Microstructure and Properties of the Copper Alloyed with Ag and Ti Powders Using Fiber Laser

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2430 ◽  
Author(s):  
Mariusz Krupiński ◽  
Paulina Ewelina Smolarczyk ◽  
Mirosław Bonek
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Chemical Composition ◽  
Abrasion Resistance ◽  
Melting Zone ◽  
Hardness Measurement ◽  
Copper Surface ◽  
Laser Alloying ◽  
Microstructure And Mechanical Properties ◽  
The Impact

The scope of the work covers the development of the relationship between the chemical composition of surface-modified copper and the diffusion of alloy elements as well as the microstructure and mechanical properties. This article presents the impact of laser alloying with titanium and silver powders on the microstructure and mechanical properties of copper. In order to investigate the phenomena occurring during the laser alloying process, microstructural studies were performed using scanning electron microscopy (SEM), optical microscopy, and energy dispersive x-ray spectroscopic (EDS) analysis of the chemical composition in micro-areas. In addition, to test the properties of the resulting alloy, abrasion resistance, hardness measurement at low loading force, and conductivity measurements were performed. As a result of alloying with Ag and Ti powders, three distinct zones were indeed recognized: re-melting zone (RZ), diffusion zone (DZ), and heat affected zone (HAZ). The surface modification that results from laser alloying increases the hardness as well as the abrasion resistance of the material. Overall, it was found that laser alloying with Ti powder increased the strength of the copper surface layer due to the formation of intermetallic phases (Cu3Ti2). It was also found that laser alloying with Ag powder changed the mechanical properties of the surface layer due to the solid solution strengthening.

scholarly journals A low/high frequency combined approach for the identification of mechanical properties of composite structural elements

2012 ◽  
Vol 39 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Ivan Bartoli ◽  
Alessandro Marzaniy
Keyword(s):  
Mechanical Properties ◽  
High Frequency ◽  
Dynamic Properties ◽  
Wave Dispersion ◽  
Guided Wave ◽  
Analytical Models ◽  
Hybrid Technique ◽  
Dynamic Features ◽  
Dynamic Identification ◽  
The Difference

A combined low/high frequency dynamic identification approach is presented. The proposed hybrid technique compares experimentally extracted dynamic properties of plates such as modal frequencies and guided wave dispersion properties with the correspondent numerically predicted ones. Identification of mechanical properties of the plates is achieved by iteratively adjusting the mechanical properties assumed in finite element and semi-analytical models through minimization of the difference between experimental and predicted dynamic features.

LIQUID POLYBUTADIENE EXTENDED ESBR/SILICA WET-MASTERBATCH COMPOSITES FOR IMPROVING ABRASION RESISTANCE AND DYNAMIC PROPERTIES OF TIRE TREAD COMPOUNDS

2021 ◽  
Author(s):  
Woong Kim ◽  
Iz Muhammet ◽  
Donghyuk Kim ◽  
Il Jin Kim ◽  
Jong-Yeop Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Abrasion Resistance ◽  
Crosslink Density ◽  
Dynamic Properties ◽  
Silica Content ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Polybutadiene Rubber ◽  
Silica Dispersion ◽  
Styrene Butadiene

ABSTRACT Silica wet-masterbatch (WMB) is a well-known technique for manufacturing high-content, highly dispersed silica-filled compounds. Emulsion styrene–butadiene rubber (ESBR)/silica WMB offers several advantages, including excellent silica dispersion and reduced hysteresis, as compared with conventional dry masterbatch (DMB) compound. However, because of the residual emulsifiers in ESBR latex, it can exhibit a decrease in the crosslink density and reductions in its mechanical properties. Moreover, the abrasion resistance cannot be significantly enhanced because of the tradeoff between the improvement in silica dispersion and decrease in crosslink density. Accordingly, the objective of this study was to improve the silica dispersion and abrasion resistance of ESBR/silica WMB compounds by using liquid polybutadiene rubber (LqBR) extended WMB. In detail, three types of LqBR were emulsified to LqBR emulsions, and three types of LqBR extended WMBs were produced by co-coagulating ESBR latex, silane-modified silica, and the LqBR emulsion. A thorough characterization was conducted with emphasis on the silica content, cure characteristics, mechanical properties, abrasion resistance, and dynamic viscoelastic properties. Based on the results, silane-terminated LqBR extended WMB vulcanizate showed a 58% improvement in the 300% modulus, 48% reduced DIN abrasion loss, and a 23% improvement in dynamic properties.

Size effect of R-TiO\(_{2}\) (Micro- and Nano-) Particles on the Mechanical Property, Weathering Durability of Water-based Acrylic Coating

2021 ◽  
Vol 31 (2) ◽  
pp. 219
Author(s):  
Thien Vuong Nguyen ◽  
Thi My Linh Dang ◽  
Tuan Anh Nguyen ◽  
Thi Huong Thuy Hoang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Weight Loss ◽  
Abrasion Resistance ◽  
Nano Particles ◽  
Accelerated Weathering ◽  
Acrylic Polymer ◽  
Water Based ◽  
Acrylic Coatings ◽  
The Difference

This work aims to clarify the difference between the influence of TiO\(_{2}\) particles at micrometer and nanometer sizes on the mechanical properties and weathering durability of water-based acrylic coatings. To prepare coatings, micro-R-TiO\(_{2}\) and nano R-TiO\(_{2}\) particles with 2 wt.% content were dispersed in the emulsion acrylic polymer by ultrasonic vibration. The coatings without TiO\(_{2}\) particles, with 2 wt.% micro R-TiO\(_{2}\) and with 2 wt.% nano R-TiO\(_{2}\) were tested for abrasion resistance, weathering aging in UV/CON accelerated weathering chamber. Weathering aging was assessed by IR quantitative analysis, the weight loss of the coating. The obtained results showed that the micro R-TiO\(_{2}\) with the 2 wt.% content enhanced simultaneously the abrasion resistance and weathering durability of water-based acrylic coatings but not as effectively as nano R-TiO\(_{2}\). Incorporation of 2 wt.% micro-R-TiO\(_{2}\) increased slightly the abrasion resistance of coating from 78.4 to 98.9 lite/mil (26% increase) while with addition of nano-R-TiO\(_{2}\) at the same content, the abrasion resistance was significantly improved from 78.4 to 129.3 lite/mil (65% increase). After 48 aging cycles, the alkane CH groups and weight of the coatings without R-TiO\(_{2}\) particles, containing 2 wt.% micro-R-TiO\(_{2}\), containing nano-R-TiO\(_{2}\) lost 34.2% and 17.4%; 23.8% and 13%; 13.7% and 13%, respectively.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Study of the character and causes of destruction of the cardan shaft of the propeller engine

2019 ◽  
Vol 85 (12) ◽  
pp. 43-50
Author(s):  
D. A. Movenko ◽  
L. V. Morozova ◽  
S. V. Shurtakov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Yield Point ◽  
Protective Coating ◽  
Fracture Pattern ◽  
Corrosion Cracking ◽  
Tempered Martensite ◽  
Neck Formation ◽  
Static Mechanism ◽  
Shaft Surface

The results of studying operational destruction of a high-loaded cardan shaft of the propeller engine made of steel 38KhN3MFA are presented to elucidate the cause of damage and develop a set of recommendations and measures aimed at elimination of adverse factors. Methods of scanning electron and optical microscopy, as well as X-ray spectral microanalysis are used to determine the mechanical properties, chemical composition, microstructure, and fracture pattern of cardan shaft fragments. It is shown that the mechanical properties and chemical composition of the material correspond to the requirements of the regulatory documentation, defects of metallurgical origin both in the shaft metal and in the fractures are absent. The microstructure of the studied shaft fragments is tempered martensite. Fractographic analysis revealed that the destruction of cardan shaft occurred by a static mechanism. The fracture surface is coated with corrosion products. The revealed cracks developed by the mechanism of corrosion cracking due to violation of the protective coating on the shaft. The results of the study showed that the destruction of the cardan shaft of a propeller engine made of steel 38Kh3MFA occurred due to formation and development of spiral cracks by the mechanism of stress corrosion cracking under loads below the yield point of steel. The reason for «neck» formation upon destruction of the shaft fragment is attributed to the yield point of steel attained during operation. Regular preventive inspections are recommended to assess the safety of the protective coating on the shaft surface to exclude formation and development of corrosion cracks.

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