Influence of the silanes on the crosslink density and crosslink structure of silica-filled solution styrene butadiene rubber compounds

2016 ◽  
Vol 24 (7) ◽  
pp. 711-727 ◽  
Author(s):  
Jong-Yeop Lee ◽  
Nam Park ◽  
Seokhwan Lim ◽  
Byeongkyu Ahn ◽  
Woong Kim ◽  
...  
2015 ◽  
Vol 3 (4) ◽  
pp. 1-5
Author(s):  
Indra Surya ◽  
Syahrul Fauzi Siregar

By using a semi-efficient vulcanization system, the cure characteristics and crosslink density of natural rubber/styrene butadiene rubber (NR/SBR) blends were studied with a blend ratio from 0 to 100% rubber. The scorch time, optimum cure time, and torque difference value of the blended rubber compounds were determined by using the Moving-Die Rheometer (MDR 2000). The crosslink density was determined by the Flory—Rehner approach. Results indicate that the scorch and cure times, ts2 and t90, of the NR/SBR blends increased with increasing the SBR content. Whilst, the maximum values of torque difference and crosslink density were performed by the NR/SBR blend with a blend ratio of 75/25.


2020 ◽  
Vol 39 (1) ◽  
pp. 81-90
Author(s):  
An Zhao ◽  
Xuan-Yu Shi ◽  
Shi-Hao Sun ◽  
Hai-Mo Zhang ◽  
Min Zuo ◽  
...  

2021 ◽  
pp. 096739112110313
Author(s):  
Ahmed Abdel-Hakim ◽  
Soma A el-Mogy ◽  
Ahmed I Abou-Kandil

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.


1999 ◽  
Vol 35 (9) ◽  
pp. 1687-1693 ◽  
Author(s):  
N.S. Saxena ◽  
P. Pradeep ◽  
G. Mathew ◽  
S. Thomas ◽  
M. Gustafsson ◽  
...  

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.


1974 ◽  
Vol 47 (2) ◽  
pp. 266-281 ◽  
Author(s):  
C. K. Das ◽  
S. Banerjee

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.


Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 767 ◽  
Author(s):  
Dániel Simon ◽  
István Halász ◽  
József Karger-Kocsis ◽  
Tamás Bárány

Because of the chemically crosslinked 3D molecular structure of rubbers, their recycling is a challenging task, especially when cost efficiency is also considered. One of the most straightforward procedures is the grinding of discarded rubber products with subsequent devulcanization. The devulcanized rubber can be used as a feedstock for fresh rubber compounds or can be blended with uncured virgin rubber and thermoplastic polymers to form thermoplastic dynamic vulcanizates (TDVs). TDVs combine the beneficial (re)processability of thermoplastics and the elastic properties of rubbers. Our current work focuses on the development of polypropylene (PP)-based TDVs with the use of a tire model rubber (MR) composed of natural rubber (NR) and styrene-butadiene rubber (SBR) in a ratio of 70/30. The research target was the partial substitution of the above fresh MR by microwave devulcanized crumb rubber (dCR). TDVs were produced by continuous extrusion, and the effects of composition (PP/MR/dCR = 40/60/0…50/35/15) and processing parameters (different screw configurations, temperature profiles, the feeding method of PP) were investigated. Results showed that the fresh rubber compound can be replaced up to 10 wt % without compromising the mechanical properties of the resulting TDV.


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

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.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1723 ◽  
Author(s):  
Magdalena Maciejewska ◽  
Anna Sowińska ◽  
Judyta Kucharska

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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