The relationship of vulcanization and structural characteristics-dispersion of organoclay-mechanical properties in (butadiene rubber/natural rubber) based nanocomposite

2017 ◽  
Vol 37 (5) ◽  
pp. 1469-1477
Author(s):  
Ahmad Zarei ◽  
Azam Jalali-Arani
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Structural Characteristics ◽  
Butadiene Rubber ◽  
Relationship Of ◽  
The Relationship

Novel Ultrasonic Technology for Devulcanization of Waste Rubbers

1995 ◽  
Vol 68 (2) ◽  
pp. 267-280 ◽  
Author(s):  
A. I. Isayev ◽  
J. Chen ◽  
A. Tukachinsky
Keyword(s):  
Mechanical Properties ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Ultrasonic Waves ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Processing Conditions ◽  
Laboratory Reactor ◽  
Plant Level ◽  
Theological Properties

Abstract A novel patented process and several reactors have been developed for devulcanization of waste rubbers. The technology is based on the use of the high power ultrasonics. The ultrasonic waves of certain levels in the presence of pressure and heat rapidly break up the three-dimensional network in crosslinked rubbers. The devulcanized rubber can be reprocessed, shaped and revulcanized in much the same way as a virgin rubber. The first laboratory reactor has been scaled up to pilot-plant level by the National Feedscrew and Machining, Inc. Various devulcanization experiments were carried out with model styrene-butadiene rubber (SBR) and with ground rubber tire (GRT). Curing behavior, Theological properties, and structural characteristics of rubbers devulcanized at various processing conditions were studied, as well as mechanical properties of revulcanized rubber samples. A possible mechanism of the devulcanization is discussed. The performed measurements indicate that the rubbers are partially devulcanized, and the devulcanization process is accompanied by certain degradation of the macromolecular chains. In spite of these observations, the processing conditions are identified at which the retention of the mechanical properties is found to be good. A further work is in progress to find the optimal conditions of devulcanization and to improve the selectivity of the process towards breaking up the chemical network only.

scholarly journals The Development of Snow and Glacier Research in Switzerland

1948 ◽  
Vol 1 (04) ◽  
pp. 192-201 ◽  
Author(s):  
R. Haefeli
Keyword(s):  
Mechanical Properties ◽  
Snow Cover ◽  
Laboratory Experiments ◽  
Relationship Of ◽  
The Relationship ◽  
Research Institute

The evolution of snow and glacier research in Switzerland is outlined. The settling, creep, viscosity and slipping of the snow cover are discussed in detail and the relationship of these comparatively simple processes to the more complex movements in a glacier are described. The importance of further research in glacier physics in connection with the crystallographic and mechanical properties of ice is stressed; certain preliminary laboratory experiments and some subjects for further research in the field are suggested. The Great Aletsch Glacier is recommended for this owing to the proximity of the Jungfraujoch Research Institute and facilities for transport by the Jungfraujoch Railway.

Effect of Sintering Temperature on Microstructure and Properties of VС/Fe Composite

2012 ◽  
Vol 430-432 ◽  
pp. 978-983
Author(s):  
Guo Jun Zhang ◽  
Zhi Ping Sun ◽  
Li Yan Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Sintering Temperature ◽  
Growth Trend ◽  
Flexure Strength ◽  
Microstructure And Properties ◽  
Whole Process ◽  
Relationship Of ◽  
The Relationship ◽  
Composite Samples

VC/Fe composite samples were fabricated by sintering at 1050, 1100 and 1150°C in vacuum. The microstructure and mechanical properties of samples were examined, and the relationship of structure and mechanical properties for VC/Fe composite sintered at different temperature were studied. The results show that fracture toughness, hardness and density is increasing obviously at 1050-1100°Cwith the increasing sintering temperature, but the growth trend increases slowly at 1100-1150°C; in whole process with temperature increased, Flexure strength heighten trend obviously. The microstructure of VC/Fe composite changed from particles piled up together to the microstructure particles closely, VC particles set gradually into Fe with temperature increased, and the gap reduced gradually.

Nylon 66 / Nomex Composite Yarn Performance Analysis

2014 ◽  
Vol 568-570 ◽  
pp. 1671-1674
Author(s):  
Gen Yang Cao ◽  
Dan Sheng ◽  
Kai Yang ◽  
Xue Feng Lu ◽  
Wei Lin Xu
Keyword(s):  
Mechanical Properties ◽  
Cluster Analysis ◽  
Performance Analysis ◽  
Confidence Interval ◽  
Polyamide 66 ◽  
Nylon 66 ◽  
Composite Yarn ◽  
Significant Difference ◽  
Relationship Of ◽  
The Relationship

The embedded composite spinning technology was applied in spinning the composite yarn of polyamide 66 and nomex .The relationship of the polyamide 66 and nomex’s content with the mechanical properties of composite yarn and hairiness was discussed. The method of cluster analysis was applied in analyzing the four kinds of yarn’s mechanical properties. And the results show that when the confidence interval is 95%, the significance of two kinds yarns were greater than 0.05. There is no significant difference between the programs. While the analysis of the hairiness data showed that the fourth solution’s harmful hairiness was much lower that the first solution’s. Therefore, the best solution is the fourth solution.

Evaluation of Grinding Performance by Mechanical Properties of Super Abrasive Wheel - Evaluation of Grade by Grinding Force

2015 ◽  
Vol 656-657 ◽  
pp. 266-270 ◽  
Author(s):  
Takekazu Sawa ◽  
Naohiro Nishikawa ◽  
Yasushi Ikuse
Keyword(s):  
Mechanical Properties ◽  
Evaluation Method ◽  
Bending Strength ◽  
Diamond Wheel ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Abrasive Wheel ◽  
Grinding Performance ◽  
Relationship Of ◽  
The Relationship

There is the grade as one of the selection criteria of a grinding wheel like WA whetstone or GC whetstone. The grade of grinding wheel is defined as an index which shows the strength of connection of a grain and a grain, and is usually estimated by bending strength. There are many papers about the relationship between the grade of a grinding wheel and the grinding performance. And, the relationship between the grade of a grinding wheel and the grinding performance is almost clear. Also, the relationship between mechanical properties of a grinding wheel and the grade is also clear. On the other hand, since the grain layer of a super abrasive grinding wheel is thin, it is difficult to apply the conventional evaluation test of the grade. And, the evaluation method of the grade which can be adapted the super abrasive grinding wheel is not established. In addition, since the grade of a super abrasive grinding wheel is a manufacture manufacturer's original standard, there is a minute difference by manufacturer. The super abrasive grinding wheel as well as the grinding wheel is conjectured that the grade influences the grinding performance. Namely, it is important to relate the grade and the mechanical properties of a grain layer. However, researches which relate the grade, the grinding performance and the mechanical properties of a super abrasive grinding wheel are not done so far. Therefore, this study examined the relationship between the mechanical properties of a grain layer of a super abrasive grinding wheel and the grade, the grinding performance. The final objective of this study is to evaluate the grinding performance from mechanical properties of a grain layer of a super abrasive grinding wheel. The purpose of this report is to clarify relationship between the grade and the grinding force in a resinoid bond diamond wheel. The specific experiment procedure is as follows. When carrying out surface grinding of the diamond sticks using a grinding wheel, the relationship of the grade and the grinding force was clarified. And based on the knowledge acquired in this experiment, relationship between the grade of a super abrasive grinding wheel and the grinding force was considered. As the results, it confirmed that the grade of a resinoid bond diamond wheel could be evaluated by the grinding force.

The Relationship of Properties of Synthetic Poly(Isoprene) and Natural Rubber in The Factory. The Effect of Non-Rubber Constituents of Natural Rubber

1973 ◽  
Vol 46 (1) ◽  
pp. 47-66 ◽  
Author(s):  
E. C. Gregg ◽  
J. H. Macey
Keyword(s):  
Natural Rubber ◽  
Protein Molecule ◽  
Insoluble Fraction ◽  
Prosthetic Group ◽  
Rubber Material ◽  
Green Strength ◽  
Denatured Protein ◽  
Low Concentrations ◽  
Relationship Of ◽  
The Relationship

Abstract The causes of some of the differences in properties between compounded natural rubber and compounded synthetic poly (isoprene) have been traced to the insoluble non-rubber material in natural rubber. This material is mostly denatured proteins and is responsible for the higher modulus, faster scorch time, higher heat buildup, and higher hot tear strength of natural rubber. These properties may be related to the pigment effect of the denatured protein to act as a reinforcing filler at low concentrations (3–4 per cent by wt) as well as a curing activator. The greater green strength of compounded natural rubber has been related to its more perfect configurational regularity which contributes to faster crystallization. The crystallite concentration increases with increasing stress and the crystallites act like a reversible reinforcing pigment which disappears when the stress is released. The faster plastication rate has been related to the synthetic stabilizers used. Natural rubber hydrocarbon has been shown to be a high molecular lactone arranged in a six membered ring. We speculate natural rubber forms as a prosthetic group connected through a lactone linkage (or the δ-hydroxy acid precursor to the lactone) to a protein molecule in the cell of hevea brasiliensis. It is this structure of a high molecular weight hydrocarbon (natural rubber) attached to a (denatured) protein molecule that accounts for the remarkable dispersability of the insoluble fraction of natural rubber in rubber solvents : the rubber end of the structure tends to dissolve in the rubber solvent while the highly polar, insoluble protein end prevents solution. This structure is the reverse of a micelle in water in principle.

The Mechanical Properties of Modified Attapulgite Reinforced Nature Rubber and Styrene-Butadiene Rubber Nanocomposites

2010 ◽  
Vol 150-151 ◽  
pp. 762-765
Author(s):  
Ji Hu Wang ◽  
Hong Bo Liu ◽  
Shao Guo Wen ◽  
Yan Shen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Coupling Agent ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
The Matrix ◽  
Modified Attapulgite ◽  
Rubber Nanocomposites ◽  
Styrene Butadiene

Attapulgite (AT)/natural rubber (NR)/ styrene-butadiene rubber (SBR) nanocomposites have been prepared after attapulgite was modified by different coupling agent. The treatment of AT caused the adhesion between AT nanorods and the nature rubber/styrene-butadiene rubber was improved, which enhanced the tensile properties of the matrix. The tensile strength of composites attained 15.6 MPa after AT was modified by 3%wt Si-69 coupling with addition of 20 phr.

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