scholarly journals Characterizing Distributions of Tensile Strength and Crack Precursor Size to Evaluate Filler Dispersion Effects and Reliability of Rubber

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 203 ◽  
Author(s):  
Christopher G. Robertson ◽  
Lewis B. Tunnicliffe ◽  
Lawrence Maciag ◽  
Mark A. Bauman ◽  
Kurt Miller ◽  
...  

Undispersed filler agglomerates or other substantial inclusions/contaminants in rubber can act as large crack precursors that reduce the strength and fatigue lifetime of the material. To demonstrate this, we use tensile strength (stress at break, σb) data from 50 specimens to characterize the failure distribution behavior of carbon black (CB) reinforced styrene-butadiene rubber (SBR) compounds. Poor mixing was simulated by adding a portion of the CB late in the mixing process, and glass beads (microspheres) with 517 μm average diameter were introduced during milling to reproduce the effects of large inclusions. The σb distribution was well described with a simple unimodal Weibull distribution for the control compound, but the tensile strengths of the poor CB dispersion material and the compounds with the glass beads required bimodal Weibull distributions. For the material with the lowest level of glass beads—corresponding to less than one microsphere per test specimen—the bimodal failure distribution spanned a very large range of σb from 13.7 to 22.7 MPa in contrast to the relatively narrow σb distribution for the control from 18.4 to 23.8 MPa. Crack precursor size (c0) distributions were also inferred from the data, and the glass beads introduced c0 values in the 400 μm range compared to about 180 μm for the control. In contrast to σb, critical tearing energy (tear strength) was unaffected by the presence of the CB agglomerates and glass beads, because the strain energy focuses on the pre-cut macroscopic crack in the sample during tear testing rather than on the microscopic crack precursors within the rubber. The glass beads were not detected by conventional filler dispersion measurements using interferometric microscopy, indicating that tensile strength distribution characterization is an important complementary approach for identifying the presence of minor amounts of large inclusions in rubber.

2011 ◽  
Vol 415-417 ◽  
pp. 237-242
Author(s):  
Zhou Da Zhang ◽  
Xue Mei Chen ◽  
Guo Liang Qu

Calcium carbonate nanoparticles (nano-CaCO3) filled powdered styrene-butadiene rubber (P(SBR/CaCO3) was prepared by adding nano-CaCO3 particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO3) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO3 particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO3) by coagulating “new particles”. The SEM results also shown that the nano-CaCO3 and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO3) particles and nano-CaCO3 dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.


1999 ◽  
Vol 72 (4) ◽  
pp. 721-730 ◽  
Author(s):  
G. R. Hamed ◽  
J. Zhao

Abstract Typical sulfur-cured vulcanizates of styrene-butadiene rubber (SBR) and natural rubber (NR) were prepared, and subjected to air-oven aging at 100 °C. Gum specimens exhibited an initial aging period in which stiffness was unchanged, while tensile strength and strain-to-break were significantly reduced. In contrast, black-filled vulcanizates stiffened during early aging. After intermediate aging times, NR specimens softened, while SBR stiffened. With prolonged aging, all compositions became hard and inextensible.


2018 ◽  
Vol 197 ◽  
pp. 12006 ◽  
Author(s):  
Indra Surya ◽  
Hanafi Ismail

By using a semi-efficient sulphur vulcanisation system, the effects of alkanolamide (ALK) addition on cure characteristics, crosslink density and tensile properties of carbon black (CB)-filled styrene-butadiene rubber (SBR) compounds were investigated. The ALK was prepared from Refined Bleached Deodorized Palm Stearin and diethanolamine and added into the CB-filled SBR compounds. The ALK loadings were 1.0, 3.0, 5.0 and 7.0 phr. It was found that ALK decreased the scorch and cure times of the CB-filled SBR compounds. ALK also improved the tensile modulus and tensile strength; especially up to a 5.0 phr of loading. The crosslink density measurement proved that the 5.0 phr of ALK exhibited the highest degree of crosslink density which caused the highest in tensile modulus and tensile strength. Due to its plasticity effect, ALK increased the elongation at break of the CB-filled SBR vulcanisates.


2011 ◽  
Vol 3 (3) ◽  
pp. 471-479
Author(s):  
M. S. I. Mozumder ◽  
M. M. Rahman ◽  
M. A. Rashid ◽  
M. A. Islam ◽  
M. E. Haque

The tensile strength (TS) and elastic modulus (ES) of non-irradiated (thermally treated) and irradiated Polypropylene (PP) - styrene butadiene rubber (SBR) composites were studied. The content of SBR (mass %) on PP and radiation dose play an important role on tensile strength and modulus of elasticity of PP-SBR composites. Tensile strength (TS) decreased markedly on increasing the SBR content on PP and even on exposing to radiation. The elastic modulus (EM) of PP-SBR composite has a tendency to increase with radiation dose and aging time but decreases with SBR loading. The water uptakes increase with SBR loading which accelerate with aging.Keywords: Polypropylene; Styrene butadiene rubber; Tensile strength; Elastic modulus.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i3.3288               J. Sci. Res. 3 (3), 481-489 (2011)


2003 ◽  
Vol 76 (2) ◽  
pp. 299-317 ◽  
Author(s):  
A. M. Shanmugharaj ◽  
Anil K. Bhowmick

Abstract Rheometric and mechanical properties, hysteresis and swelling behavior of the Styrene-Butadiene Rubber vulcanizates (SBR) filled with unmodified and novel electron beam modified surface treated dual phase fillers were investigated. Scorch time increases for these modified filler loaded vulcanizates due to introduction of quinone type oxygen on the surface. Electron beam modification of dual phase filler in the absence of trimethylol propanetriacrylate (TMPTA) or triethoxysilylpropyltetrasulphide (Si-69) significantly improves the modulus of the SBR vulcanizates, whereas the values of tensile strength and elongation at break drop. However, presence of TMPTA or silane slightly increases the modulus with significant improvement in tensile strength. This effect is more pronounced at higher loading of these modified fillers in SBR vulcanizates. These variations in modulus and tensile strength are explained by the equilibrium swelling data, Kraus plot and a new mathematical model interpreting the polymer-filler interaction. Hysteresis loss ratio of SBR vulcanizates loaded with irradiated fillers in absence and presence of TMPTA or silane increases due to highly aggregated structure of the filler.


2010 ◽  
Vol 150-151 ◽  
pp. 762-765
Author(s):  
Ji Hu Wang ◽  
Hong Bo Liu ◽  
Shao Guo Wen ◽  
Yan Shen

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.


1996 ◽  
Vol 69 (4) ◽  
pp. 696-712 ◽  
Author(s):  
Mario A. Llosent ◽  
Luis M. Gugliotta ◽  
Gregorio R. Meira

Abstract This paper deals with data treatment problems that arise when turbidimetry is employed to estimate the particle size distribution (PSD) of soft polymer latexes with low diameter limits around 40 nm. Scanning electron microscopy and dynamic light scattering were used as comparison techniques. Industrial latexes of styrene-butadiene rubber (SBR) and of acrylonitrile-butadiene rubber (NBR) were investigated. The data treatment involved the use of Mie's Model to obtain an average diameter and/or the complete PSD. For estimating the complete PSD, a least squares optimization (with an imposed distribution shape) and a numerical deconvolution procedure (without assumptions on the distribution shape) were attempted. A synthetic example was solved to investigate the limits of the applied numerical methods. For the polymer refractive index functions, Cauchy's Law was used — and its adequate adjustment proved essential for good turbidimetric estimations. A reasonable agreement between the turbidity measurements and the other independent estimations was verified. For the SEM observations, the soft latexes were hardened by irradiation before observation, but negligible diameter variations were detected.


2013 ◽  
Vol 812 ◽  
pp. 236-240
Author(s):  
Mohd Zaki Nurul Ayunie ◽  
Ahmad Zafir Romli ◽  
M.A. Wahab ◽  
Mohd Hanafiah Abidin

The effects of epoxidized palm oil (EPO) content in carbon black filled styrene butadiene rubber (SBR) on tensile strength, elongation at break and crosslink density were investigated. Five different loadings of EPO in parts per hundred rubbers (phr) were used to test the tensile strength of the carbon black filled SBR which showed a decreasing trend as the content of EPO in the vulcanizates increased. In contrast, elongation at break showed the opposite trend where the elongation at break increased as the content of the EPO increased. The SBR vulcanizates with the highest content of EPO gave the highest value of elongation at break which is 2393.56%. In the case of swelling index, it was found to increase as the amount of EPO increased.


2017 ◽  
Vol 2 (12) ◽  
pp. 31
Author(s):  
Ali Abed Salman

Styrene butadiene rubber (SBR) is considered to be one of the greatest important polymeric materials used as a bond, so we discussed in this study to improve its properties .This study covers the effect of silica fume on mechanical properties of styrene butadiene rubber reinforced with silica fume. The composites were prepared with (1 to 3 wt. %) of silica fume particles .The results had indicated  that the tensile strength and flexural strength are improved by (11.6% and 13.5%) respectively at 2 wt% and the hardness is  improved by (9.3%) at 3wt%.


2014 ◽  
Vol 3 (2) ◽  
pp. 1-4
Author(s):  
Indra Surya ◽  
Siswarni MZ

By using a semi-efficient vulcanization system, the effect of Epoxidized Natural Rubber (ENR) as a compatibilizer in silica-filled Styrene Butadiene Rubber (SBR) compound was carried out. The ENR was incorporated into the silica-filled SBR compound at 5.0 and 10.0 phr. An investigation was carried out to examine the effect of ENR on cure characteristics and tensile properties of the silica-filled SBR compound. It was found that ENR gave enhanced cure rate to the silica-filled SBR compound. ENR also exhibited a higher torque difference, tensile modulus, and tensile strength up to 10.0 phr. The study of rubber - filler interaction proved that the addition of ENR to the silica-filled SBR system improved the rubber - filler interaction.


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