Studies on Dicumyl Peroxide Vulcanization of Styrene—Butadiene Rubber in Presence of Sulfur and 2-Mercaptobenzothiazole

Abstract The effect of sulfur, MBT, zinc oxide, and stearic acid on the DCP vulcanization of SBR has been studied. DCP decomposition obeys first order kinetics in all cases, but its rate constant is higher in presence of MBT. Sulfur and MBT reduce the crosslink density due to DCP. In the mixes containing sulfur, MBT, zinc oxide, and stearic acid in presence of DCP the crosslink density is initially additive. Here oxidation of some pendent vinyl groups are effected by DCP, and these groups also take part in thiol addition reaction with MBT. The thiazole accelerated sulfuration of SBR proceeds fundamentally by the same mechanism as reported for NR, but the details show slight difference chiefly due to the presence of pendent vinyl groups and styrene units in the chain and due to the absence of pendent methyl groups in SBR.

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Zinc Complexes with 1,3-Diketones as Activators for Sulfur Vulcanization of Styrene-Butadiene Elastomer Filled with Carbon Black

Materials ◽

10.3390/ma14143804 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3804

Author(s):

Magdalena Maciejewska ◽

Anna Sowińska ◽

Agata Grocholewicz

Keyword(s):

Zinc Oxide ◽

Functional Properties ◽

Crosslink Density ◽

Zinc Complexes ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Sulfur Vulcanization ◽

Cure Characteristic ◽

And Performance ◽

Styrene Butadiene

Zinc oxide nanoparticles (N-ZnO) and zinc complexes with 1,3-diketones of different structures were applied instead of microsized zinc oxide (M-ZnO) to activate the sulfur vulcanization of styrene-butadiene rubber (SBR). The influence of vulcanization activators on the cure characteristics of rubber compounds, as well as crosslink density and functional properties of SBR vulcanizates, such as tensile properties, hardness, damping behavior, thermal stability and resistance to thermo-oxidative aging was explored. Applying N-ZnO allowed to reduce the content of zinc by 40% compared to M-ZnO without detrimental influence on the cure characteristic and performance of SBR composites. The activity of zinc complexes in vulcanization seems to strongly depend on their structure, i.e., availability of zinc to react with curatives. The lower the steric hindrance of the substituents and thus the better the availability of zinc ions, the greater was the activity of the zinc complex and consequently the higher the crosslink density of the vulcanizates. Zinc complexes had no detrimental effect on the time and temperature of SBR vulcanization. Despite lower crosslink density, most vulcanizates with zinc complexes demonstrated similar or improved functional properties in comparison with SBR containing M-ZnO. Most importantly, zinc complexes allowed the content of zinc in SBR compounds to be reduced by approximately 90% compared to M-ZnO.

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Novel modification of styrene butadiene rubber/acrylic rubber blends to improve mechanical, dynamic mechanical, and swelling behavior for oil sealing applications

Polymers and Polymer Composites ◽

10.1177/09673911211031351 ◽

2021 ◽

pp. 096739112110313

Author(s):

Ahmed Abdel-Hakim ◽

Soma A el-Mogy ◽

Ahmed I Abou-Kandil

Keyword(s):

Mechanical Properties ◽

Crosslink Density ◽

Physical And Mechanical Properties ◽

Dynamic Mechanical Properties ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Rubber Blends ◽

Dynamic Mechanical ◽

Oil Resistance ◽

Styrene Butadiene

Blending of rubber is an important route to modify properties of individual elastomeric components in order to obtain optimum chemical, physical, and mechanical properties. In this study, a novel modification of styrene butadiene rubber (SBR) is made by employing acrylic rubber (ACM) to obtain blends of outstanding mechanical, dynamic, and oil resistance properties. In order to achieve those properties, we used a unique vulcanizing system that improves the crosslink density between both polymers and enhances the dynamic mechanical properties as well as its resistance to both motor and break oils. Static mechanical measurements, tensile strength, elongation at break, and hardness are improved together with dynamic mechanical properties investigated using dynamic mechanical analyses. We also proposed a mechanism for the improvement of crosslink density and consequently oil resistance properties. This opens new opportunities for using SBR/ACM blends in oil sealing applications that requires rigorous mechanical and dynamic mechanical properties.

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Effects of alkanolamide addition on cure characteristics, crosslink density and tensile properties of carbon-black-filled styrene-butadiene rubber compounds

MATEC Web of Conferences ◽

10.1051/matecconf/201819712006 ◽

2018 ◽

Vol 197 ◽

pp. 12006 ◽

Cited By ~ 5

Author(s):

Indra Surya ◽

Hanafi Ismail

Keyword(s):

Tensile Strength ◽

Carbon Black ◽

Tensile Properties ◽

Crosslink Density ◽

Density Measurement ◽

Tensile Modulus ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Cure Characteristics ◽

Styrene Butadiene

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.

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Evaluation of silane effect as a coupling agent for metakaolin

Journal of Elastomers & Plastics ◽

10.1177/0095244319877667 ◽

2019 ◽

Vol 52 (7) ◽

pp. 593-608

Author(s):

Alessandra de Alencar Padua Gabino ◽

Cléverson Fernandes Senra Gabriel ◽

Ana Maria Furtado de Sousa ◽

Cristina Russi Guimarães Furtado ◽

Bluma Guenther Soares

Keyword(s):

Crosslink Density ◽

Coupling Effect ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Reference Compound ◽

Maximum Torque ◽

Silica Sample ◽

Automobile Tire ◽

Two Samples ◽

Styrene Butadiene

This study aimed at evaluating the coupling effect of silane Si69 bis(triethoxysilylpropyl)tetrasulfide in metakaolin (MK) in automobile tire tread compounds based on a styrene–butadiene rubber/butadiene rubber blend. A reference compound of a typical tread recipe, filled with silica and carbon black, was used as a reference due to the acknowledged effect of TESPT in silica incorporation in elastomers. A silica sample without silane was also prepared. Silica was then completely substituted by MK, producing two samples, with and without silane. The samples were tested for crosslink density, rheometry, and morphology, and the vulcanization reaction parameters were determined and evaluated. Silane improved the interaction between MK and the polymer matrix, evidenced by the increase in crosslink density and vulcanization reaction rate, the same effect silane causes on silica-filled composites. Morphology also revealed that silane increased MK dispersion and adhesion to rubber. On the other hand, MK seems not to be as reinforcing as silica, considering that maximum torque is related to the stiffness of the material, with MK exhibiting lower values for this parameter.

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Organic Zinc Salts as Pro-Ecological Activators for Sulfur Vulcanization of Styrene–Butadiene Rubber

Polymers ◽

10.3390/polym11101723 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1723 ◽

Cited By ~ 4

Author(s):

Magdalena Maciejewska ◽

Anna Sowińska ◽

Judyta Kucharska

Keyword(s):

Zinc Oxide ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Zinc Ions ◽

Organic Zinc ◽

Rubber Compounds ◽

Curing Characteristics ◽

Sulfur Vulcanization ◽

Zinc Salts ◽

Styrene Butadiene

Organic zinc salts and complexes were applied as activators for sulfur vulcanization of styrene–butadiene elastomer (SBR) in order to reduce the content of zinc ions in rubber compounds as compared with conventionally used zinc oxide. In this article, the effects of different organic zinc activators on the curing characteristics, crosslink densities, and mechanical properties of SBR as well as the aging resistance and thermal behavior of vulcanizates are discussed. Organic zinc salts seem to be good substitutes for zinc oxide as activators for sulfur vulcanization of SBR rubber, without detrimental effects to the vulcanization time and temperature. Moreover, vulcanizates containing organic zinc salts exhibit higher tensile strength and better damping properties than vulcanizate crosslinked with zinc oxide. The application of organic zinc activators allows the amount of zinc ions in SBR compounds to be reduced by 70–90 wt % compared to vulcanizate with zinc oxide. This is very important for ecological reasons, since zinc oxide is classified as being toxic to aquatic species.

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Viscosity and Molecular Weight of Masticated Styrene-Butadiene Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3535713 ◽

1965 ◽

Vol 38 (4) ◽

pp. 961-966 ◽

Cited By ~ 7

Author(s):

S. K. Bhatnagar ◽

S. Banerjee

Keyword(s):

Molecular Weight ◽

Intrinsic Viscosity ◽

Crosslink Density ◽

Empirical Relation ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Mooney Viscosity ◽

The Times ◽

Styrene Butadiene

Abstract Changes in the value of [η], [ηm], K′, (M) and μ of SBR masticated in the cold at 25.0 ± 5.0° C in presence of oxygen with the times of mastication are reported. An empirical relation has been developed between the intrinsic viscosity [η] and Mooney viscosity [ηm] which permits molecular weight of the rubber to be determined directly from Mooney viscosity. The value of g which appears in the Flory equation connecting true crosslink density with the physically determined one has been calculated for unfilled SBR.

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Effect of Epoxidized Palm Oil Loading on the Swelling and Mechanical Properties of SBR Vulcanizates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.812.236 ◽

2013 ◽

Vol 812 ◽

pp. 236-240

Author(s):

Mohd Zaki Nurul Ayunie ◽

Ahmad Zafir Romli ◽

M.A. Wahab ◽

Mohd Hanafiah Abidin

Keyword(s):

Tensile Strength ◽

Carbon Black ◽

Palm Oil ◽

Crosslink Density ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Elongation At Break ◽

Epoxidized Palm Oil ◽

Opposite Trend ◽

Styrene Butadiene

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.

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Processing of styrene butadiene rubber–carbon black nanocomposites with gradation of crosslink density: Static and dynamic mechanical characterization

Materials Science and Engineering A ◽

10.1016/j.msea.2008.02.018 ◽

2008 ◽

Vol 491 (1-2) ◽

pp. 454-460 ◽

Cited By ~ 19

Author(s):

S.S. Ahankari ◽

Kamal K. Kar

Keyword(s):

Carbon Black ◽

Crosslink Density ◽

Mechanical Characterization ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Dynamic Mechanical ◽

Styrene Butadiene

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Cure Characteristics and Mechanical Properties of NR/ SBR Blends Filled with Nano-sized CaCO3

Progress in Rubber Plastics and Recycling Technology ◽

10.1177/147776060502100202 ◽

2005 ◽

Vol 21 (2) ◽

pp. 101-115

Author(s):

Chaoying Wan ◽

Yong Zhang ◽

Yin Zhu ◽

Yinxi Zhang

Keyword(s):

Mechanical Properties ◽

Surface Modification ◽

Stearic Acid ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Cure Rate ◽

Cure Characteristics ◽

Cure Time ◽

Surface Modified ◽

Styrene Butadiene

Four kinds of nano-sized calcium carbonate (CaCO3) surface-modified with stearic acid, aluminate, titanate and aluminate-titanate complex coupling agents, were used to reinforce natural rubber (NR)/styrene-butadiene rubber (SBR) blends. The effects of surface modification and CaCO3 content on the cure characteristics, swelling behaviour, and mechanical properties of NR/SBR blends were studied. The surface modification of CaCO3 improved the processing and mechanical properties, and the stearic acid coated CaCO3 (SA-CaCO3) had finer dispersion and produced a better reinforcement effect than the other modified CaCO3. Furthermore, a commercial high abrasion furnace carbon black (HAF) was used for comparison. The results showed that both CaCO3 and HAF increased the cure rate, reduced the optimum cure time and improved the mechanical properties of NR/SBR blends at appropriate filler contents. The tensile strength of filled NR/SBR composites reached its maximum value when the SA-CaCO3 content was 50 phr or the HAF content was 30 phr. The modulus at 200%, tear strength, and Shore A hardness of filled NR/SBR composites all increased with increasing filler content. The CaCO3 reinforced the NR/SBR blends to some extent, though it was still not as effective as HAF.

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