scholarly journals Properties of Vulcanized Polyisoprene Rubber Composites Filled with Opalized White Tuff and Precipitated Silica

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Suzana Samaržija-Jovanović ◽  
Vojislav Jovanović ◽  
Gordana Marković ◽  
Ivana Zeković ◽  
Milena Marinović-Cincović
Keyword(s):  
Mechanical Properties ◽  
Production Efficiency ◽  
Average Particle Size ◽  
Rubber Matrix ◽  
Average Particle ◽  
Cross Link ◽  
Rubber Composites ◽  
Precipitated Silica ◽  
Reinforcing Effects ◽  
Cure Characteristic

Opalized white tuff (OWT) with 40 μm average particle size and 39.3 m2/g specific surface area has been introduced into polyisoprene rubber (NR). Their reinforcing effects were evaluated by comparisons with those from precipitated silica (PSi). The cure characteristic, apparent activation energy of cross-link (Eac) and reversion (Ear), and mechanical properties of a variety of composites based on these rubbers were studied. This was done using vulcanization techniques, mechanical testing, and scanning electron microscopy (SEM). The results showed that OWT can greatly improve the vulcanizing process by shortening the time of optimum cure (tc90) and the scorch time (ts2) of cross-linked rubber composites, which improves production efficiency and operational security. The rubber composites filled with 50 phr of OWT were found to have good mechanical and elastomeric properties. The tensile strengths of the NR/OWT composites are close to those of NR/PSi composites, but the tear strength and modulus are not as good as the corresponding properties of those containing precipitated silica. Morphology results revealed that the OWT is poorly dispersed in the rubber matrix. According to that, the lower interactions between OWT and polyisoprene rubber macromolecules are obtained, but similar mechanical properties of NR/OWT (100/50) rubber composites compared with NR/PSi (100/50) rubber composites are resulted.

scholarly journals Hybrid Silica-Based Fillers in Nanocomposites: Influence of Isotropic/Isotropic and Isotropic/Anisotropic Fillers on Mechanical Properties of Styrene-Butadiene (SBR)-Based Rubber

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2413
Author(s):  
Mariapaola Staropoli ◽  
Vincent Rogé ◽  
Enzo Moretto ◽  
Joffrey Didierjean ◽  
Marc Michel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silica Nanoparticles ◽  
Synergetic Effect ◽  
Mechanical Analysis ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Precipitated Silica ◽  
Scanning Transmission ◽  
Styrene Butadiene

The improvement of mechanical properties of polymer-based nanocomposites is usually obtained through a strong polymer–silica interaction. Most often, precipitated silica nanoparticles are used as filler. In this work, we study the synergetic effect occurring between dual silica-based fillers in a styrene-butadiene rubber (SBR)/polybutadiene (PBD) rubber matrix. Precipitated Highly Dispersed Silica (HDS) nanoparticles (10 nm) have been associated with spherical Stöber silica nanoparticles (250 nm) and anisotropic nano-Sepiolite. By imaging filler at nano scale through Scanning Transmission Electron Microscopy, we have shown that anisotropic fillers align only in presence of a critical amount of HDS. The dynamic mechanical analysis of rubber compounds confirms that this alignment leads to a stiffer nanocomposite when compared to Sepiolite alone. On the contrary, spherical 250 nm nanoparticles inhibit percolation network and reduce the nanocomposite stiffness.

Experimental Study on the Effects of Internal Erosion on the Physical and Mechanical Properties of Tailings Under Unsteady Seepage

2021 ◽  
Author(s):  
Rong Gui ◽  
Guicheng He
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Shear Strength ◽  
Average Particle Size ◽  
Physical And Mechanical Properties ◽  
Internal Erosion ◽  
Average Particle ◽  
Sand Column ◽  
Sedimentary Characteristics ◽  
Seepage Erosion

Abstract In this paper, the hydraulic sedimentary model was established to investigate the effects of dry beach slope on the sedimentary characteristics of tailings, and the sand column model was built to investigate the effects of seepage erosion on the physical and mechanical properties of sedimentary tailings under unsteady seepage.The results show that the slope of dry beach have a great effect on the sedimentary characteristics of tailings, the average particle size of tailings decreases along the slope of dry beach, and the larger the slope, the more obvious the stratification of the tailings. The migration of fine-grained tailings caused by seepage erosion increases the permeability of the tailings and reduces the shear strength of the tailings. After seepage erosion,the average particle size of 1#tailings sample, 2#tailings sample and 3#tailings sample increased by 6.4%, 12.0% and 2.4% respectively, the hydraulic conductivity of 1# tailings sample, 2# tailings sample and 3# tailings increased by 27.2%,17.9%, and 15.3% respectively after internal erosion, and the shear strength of 1#tailings sample, 2#tailings sample and 3#tailings sample tailings sample decreased by 20.9 %, 15.1% and 12.4% respectively.

Study on Mechanical Properties of AA6061/SiC/B4C Hybrid Nano Metal Matrix Composites

2021 ◽  
Vol 1034 ◽  
pp. 35-42
Author(s):  
Shubhajit Das ◽  
M. Chandrasekaran ◽  
Sutanu Samanta
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Matrix Material ◽  
Average Particle Size ◽  
Volume Ratio ◽  
Casting Process ◽  
Hybrid Nanocomposites ◽  
Average Particle ◽  
Matrix Composites ◽  
Structural Applications

The present work investigates the mechanical characterization of aluminium alloy (AA) 6061 based hybrid nanometal matrix composites (MMCs) fabricated using conventional stir casting process. Two compositions viz., AA6061+1.5 wt.% B4C+0.5 wt.% SiC (Hybrid A) and AA6061+1.5 wt.% B4C+1.5 wt.% SiC (Hybrid B) was prepared and its mechanical properties such as microhardness, tensile, compressive, flexural and impact strength were investigated to compare with unreinforced AA6061. SiC and B4C ceramic particles (purity 99.89%) of average particle size of 50 nm were used as reinforcements. Significant enhancement in microhardness of 30.2% and 31.02% for hybrid A and B are observed respectively. The ultimate tensile strength (UTS) increased by 10.72% and 16.55% for hybrid A and B respectively. Improved interaction because of the enhanced surface to volume ratio at the interface resulted in improvement of mechanical properties. Field emission scanning electron microscopy (FESEM) of the fractured surface shows brittle fracture because of the incorporation of the ceramic reinforcements in the matrix material. The developed AA6061/SiC/B­4C hybrid nanocomposites show improved mechanical properties for high-performance structural applications.

scholarly journals Influence of Eco-Friendly Processing Aids on Silica-Based Rubber Composites

2020 ◽  
Vol 10 (20) ◽  
pp. 7244
Author(s):  
Sung Ho Song
Keyword(s):  
Mechanical Properties ◽  
Rolling Resistance ◽  
Fatigue Properties ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Composites ◽  
Dispersing Agent ◽  
Styrene Butadiene ◽  
Processing Aids

As eco-friendly “green tires” are being developed in the tire industry, conventionally used carbon black is being replaced with silica in rubber compounds. Generally, as a lubricant and dispersing agent, processing aids containing zinc ions have been employed as additives. However, as zinc is a heavy metal, alternative eco-friendly processing aids are required to satisfy worldwide environmental concerns. Furthermore, non-toxic, degradable, and renewable processing aids are required to improve the mechanical properties of the rubber composites. In this study, we evaluated the effects of diverse silica-based processing aids containing hydrocarbon, benzene, and hydroxyl functional groups on the mechanical properties of rubber composites. Among them, rubber composites that used amphiphilic terpene phenol resin (TPR) with hydrophilic silica showed compatibility with the hydrophobic rubber matrix and were revealed to improve the mechanical and fatigue properties. Furthermore, owing to the enhanced dispersion of silica in the rubber matrix, the TPR/styrene butadiene rubber composites exhibited enhanced wet grip and rolling resistance. These results indicated that TPR had multifunctional effects at low levels and has the potential for use as a processing aid in silica-based rubber composites in tire engineering applications.

Mechanical properties and erosive behaviour of 10TiO2-Cr2O3 coated CA6NM turbine steel under accelerated conditions

2019 ◽  
Vol 16 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Khushdeep Goyal
Keyword(s):  
Mechanical Properties ◽  
Mass Loss ◽  
Average Particle Size ◽  
Average Particle ◽  
Slurry Erosion ◽  
Experimental Conditions ◽  
Content Type ◽  
Uncoated Steel ◽  
Erosion Test ◽  
Turbine Steel

Purpose This paper aims to evaluate the mechanical properties and slurry erosion behaviour of 10TiO2-Cr2O3 coated turbine steel. Design/methodology/approach Slurry erosion experiments were performed on the coated turbine steel specimens using slurry erosion test rig under accelerated conditions such as rotational speed, average particle size and slurry concentration. Surface roughness tester, Vickers microhardness tester and scanning electron microscope were used to analyse erosion mechanism. Findings Under all experimental conditions, 10TiO2-Cr2O3 coated steel showed better slurry erosion resistance in comparison with Al2O3 coated and uncoated steel specimens. Each experimental condition indicated a significant effect on the erosion rate of both coatings and uncoated steel. The surface analysis of uncoated eroded specimen revealed that plastic deformation, ploughing and deep craters formation were the reasons for mass loss, whereas microchipping, ploughing and microcutting were the reasons for mass loss of coated specimens. Originality/value The present investigation provides novel insight into the comparative slurry erosion performance of high velocity oxy fuel deposited 10TiO2-Cr2O3 and Cr2O3 coatings under various environmental conditions. To form modified powder, 10 Wt.% TiO2 was added to 90 Wt.% Cr2O3.

Properties of Natural Rubber Nanocomposites Reinforced with Carbon Nanotubes

2015 ◽  
Vol 1109 ◽  
pp. 195-199 ◽  
Author(s):  
Abd Aziz Azira ◽  
Dayang Habibah Abangismawi I. Hassim ◽  
D. Verasamy ◽  
Abu Bakar Suriani ◽  
M. Rusop
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Natural Rubber ◽  
Considerable Increase ◽  
Physical And Mechanical Properties ◽  
Rubber Matrix ◽  
Rubber Composites ◽  
Transmission Electron ◽  
Maximum Conductivity ◽  
Polymer Latex

In order to achieve improvements in the performance of rubber materials, the development of carbon nanotube (CNT)-reinforced rubber composites was attempted. The CNT/epoxidised natural rubber (ENR) nanocomposite was prepared through latex technology. Physical and mechanical properties of the CNT/ENR nanocomposites were characterized in contrast to the carbon black (CB)/ENR composite. The dispersion of the CNTs in the rubber matrix and interfacial bonding between them were rather good; monitored transmission electron microscopy and scanning electron microscopy. The mechanical properties of the CNT-reinforced ENR showed a considerable increase compared to the neat ENR and traditional CB/ENR composite. The storage modulus of the CNT/ENR nanocomposites greatly exceeds that of neat ENR and CB/ENR composites and a maximum conductivity of about 1 S m-1 can be achieved. The approach presented can be adapted to other CNT/polymer latex systems.

The Effect of Excess Silane-69 Used for Surface Modification on Cure Characteristic and Mechanical Properties of Precipitated Silica Filled Natural Rubber (PSi/NR)

2009 ◽  
Vol 79-82 ◽  
pp. 2171-2174 ◽  
Author(s):  
Chanchai Thongpin ◽  
C. Sangnil ◽  
P. Suerkong ◽  
A. Pongpilaiprertti ◽  
Narongrit Sombatsompop
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Crosslinking Density ◽  
High Concentration ◽  
Precipitated Silica ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Cure Time ◽  
Cure Characteristic ◽  
Characterization Test

This research is concentrated on the effect of concentration of silane-69 used for surface modification on precipitated silica (PSi), on cure characteristic and mechanical properties of PSi filled NR. The PSi content in this study was fixed at 20 phr in order to reveal the effect of silane used to modify PSi, on NR compound and vulcanizate. Moving Die Rheometer (MDR) was used to characterize cure characteristic of rubber compounds. Generally, scorch and cure time of NR would increase with the addition of PSi due to the absorption of accelerator on its surface whereas the addition of Si-69 modified PSi would reduce both scorch and cure time. It was found in this research that the excess amount of Si-69 used increased scorch and cure time of rubber compounds. This was thought to be that the excess of Si-69 led to the formation of polysiloxane clusters which could absorb accelerator in rubber compound and resulted in a prolonged scorch and cure time. In term of vulcanized rubber, it was found that maximum torque increased with the concentration of Si-69 up to 6 %. The polysiloxane formed during the cure characterization test was responsible for the slightly decreased torque after 6% of Si-69 treatment. Nonetheless, even with high concentration of Si-69 used, torque was still higher than that of untreated PSi filled NR. This is widely understood that sulfur atoms in Si-69 molecule are able to participate in the bonding between rubber and silane molecules resulted in the enhancement of crosslink density of the vulcanizate rubber. The increased of modulus at 200 % elongation, tensile strength under tension, with the silane concentration, was evidence of the crosslink enhancement. Tear strength and hardness of the vulcanizates exhibiting the increment, with the silane used, also clearly confirmed the bonding between Si-69 and rubber molecules. It was elucidated from the research that excess of Si-69 would lead to polysiloxane formation, cluster form of silane and crosslinking density. Scanning Electron Microscope (SEM) micrographs and swelling test are also presented to confirm the phenomena.

Processibility and Mechanical Properties of Mullite-Filled Styrene Butadiene Rubber Composites

2011 ◽  
Vol 284-286 ◽  
pp. 401-410
Author(s):  
Qiong Qiong Liu
Keyword(s):  
Mechanical Properties ◽  
Silane Coupling Agent ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Composites ◽  
Precipitated Silica ◽  
Roll Mill ◽  
Silane Coupling ◽  
Styrene Butadiene ◽  
Reinforcing Filler

Mullite (3A12O3·2SiO2) is an aluminosilicate ceramic of great technological importance. We investigated its potential as fillers in rubber. Mullites untreated or treated with 3% γ-mecapto-propyltrimethoxysilane (A-189) were added into styrene-butadiene rubber (SBR) materials on a laboratory-sized two-roll mill. For comparison, commercial precipitated silica was also used. The effect of these fillers on the cure characteristics, processibility and mechanical properties of SBR at various loadings, ranging from 0 to 50 phr was investigated. The results showed that mullite was a semi-reinforcing filler for SBR materials and exhibits better overall cure properties, lower Mooney viscosity, lower tensile set, better resilience as compared to precipitated silica, while it is inferior to precipitated silica especially with regard to tensile strength, tear strength and abrasion resistance. The presence of the silane coupling agent can enhance mechanical properties of filled SBR vulcanizates to some extent.

Reinforcement from In-Situ Precipitated Silica in Polysiloxane Elastomers under Various Types of Deformation

1992 ◽  
Vol 274 ◽  
Author(s):  
James E. Mark ◽  
Shuhong Wang ◽  
Ping Xu ◽  
Jianye Wen
Keyword(s):  
Mechanical Properties ◽  
Uniaxial Elongation ◽  
Compression Set ◽  
Precipitated Silica ◽  
Equilibrium Swelling ◽  
Rupture Energy ◽  
End Linking ◽  
Reinforcing Effects

ABSTRACTElastomeric networks prepared by tetrafunctionally end linking hydroxyl-terminated poly(dimethylsiloxane) chains (PDMS) were filled by the in-situ precipitation of silica. The resulting networks were investigated under uniaxial elongation, biaxial extension, shear, and torsion in order to characterize the resulting changes in mechanical properties. Compared with the unfilled networks, the silica-filled materials showed large reinforcing effects. Specifically, their values of the modulus, ultimate strength, and rupture energy increased significantly. The results thus indicate that the PDMS networks filled by the in-situ precipitation of silica have very good mechanical properties in several, rather different deformations. Examples of other deformations of interest are equilibrium swelling, and dynamic cycling for characterization of compression set.

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