Ionic Crosslinking of Carboxylated SBR

1983 ◽  
Vol 56 (5) ◽  
pp. 942-958 ◽  
Author(s):  
Kyosaku Sato

Abstract 1. Ionic bonding of carboxylated SBR with zinc oxide is detectable by means of measurements of the temperature dependence of tan δ. There is an α peak in the region of 60°C at 3.5 Hz. The position and shape of the α peak are strongly dependent on the state of cure of the vulcanizates. Without permanent crosslinking, the α peak is a plateau; as the crosslink density increases, the α peak becomes sharper and shifts to lower temperatures. The presence of carbon black causes the α peak to shift to higher temperatures, regardless of the presence of permanent crosslinks. 2. Ionic bonds in carboxylated SBR reacted with zinc oxide are in the form of ion clusters which function as crosslinks at room temperature. The ionic crosslinks provide carboxylated SBR with high tensile strength in the absence of reinforcing fillers. The presence of carbon black causes the 300% modulus to increase. The ionic crosslinks are labile, and the strength is lost at moderately elevated temperatures. A mixed cure system consisting of both sulfur and zinc oxide provides higher heat resistance than either of the single cure systems.

2015 ◽  
Vol 88 (3) ◽  
pp. 412-420 ◽  
Author(s):  
Huan Zhang ◽  
Zhiyi Zhang ◽  
Guizhe Zhao ◽  
Yaqing Liu ◽  
Ye Li ◽  
...  

ABSTRACT Carbon black and silica have long been recognized as reinforcing fillers, but their effect on the dynamic properties and heat buildup of vulcanizates is rarely reported. Therefore, natural rubber composites filled by carbon black with different particle size and silica were prepared. The Payne effect and heat buildup progressively decrease with an increase of carbon black particle size because of weaker filler network structure and better dispersion, the N754 filled sample in particular shows the lowest value, only 4.7 °C. The tensile strength and tear strength of composites all increase with the reducing carbon black particle size. SiO2-filled composites exhibit obvious Payne effects and inferior mechanical properties; at high strains (>10%), tan δ of SiO2-filled composites surpasses all that of carbon black–filled composites, due to the surface silanol groups on the silica surface and due to the decreased cross-link density.


Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.


2017 ◽  
Vol 266 ◽  
pp. 172-176
Author(s):  
Pattarawadee Maijan ◽  
Nitinart Saetung ◽  
Wisut Kaewsakul

Mixing behaviors of the compounds filled with different reinforcing fillers were studied in correlation with compound and vulcanizate properties. Four filler systems were used including: 1) silica plus small amount of silane coupling agent; 2) carbon black; 3) pre-modified silica; and 4) silica+silane-carbon black mixed one. The results have shown that silica provides longer optimum cure time and shorter cure rate than carbon black due to accelerator adsorption on silica surface. In addition, owing to highly polar nature on silica surface the silica-based compounds show rather high viscosity, attributed to stronger filler-filler interaction as can be confirmed by Payne effect and reinforcement index. However, the commercial surface treatment or pre-modified form of silica shows superior properties than in-situ modification of silica by silane during mixing, while it gives comparable properties to carbon black-based compound. Tensile properties of vulcanizates show a good correlation with the basic properties of their compounds.


Author(s):  
Vladimir M. Makarov ◽  
Elena L. Nikitina ◽  
Olga Yu. Solovyeva

The effect of the mechanochemical treatment of components of the sulphurous vulcanizing group on the properties of rubber mixtures and rubbers on the basis of 1,4-cis-polyisopren, filled with carbon black N330, was investigated. The mechanochemical activation of the components was carried out by processing them in a device that is a reactor with magnetic elements and a coil of inductivity. When connecting the inductor to the electrical grid, the working elements are exposed to the magnetic field and began to move intensiocly way with the transfer of energy to powdered particles. The treatment of both individual components: zinc oxide, accelerators, and all components of the sulfur vulcanizing group leads to an increase in the rate and degree of structuring of rubber in the main vulcanization period and a decrease in the tendency of rubber to reverse in the postvulcanization stage. In this case the values of elasticity modules increase and mechanical losses in vulcanizates reduce as the temperature increases. Most of these changes in the properties of mixtures and rubbers are expressed in the processing of individual accelerators and together all components of the vulcanizing group. Storage of activated ingredients for 30 days does not lead to significant changes in the structure and properties of rubber mixtures and vulcanizates.


RSC Advances ◽  
2020 ◽  
Vol 10 (68) ◽  
pp. 41837-41845
Author(s):  
Sunil Kumar ◽  
Dongwoon Kang ◽  
Hyeryeon Hong ◽  
Malik Abdul Rehman ◽  
Yeon-jae Lee ◽  
...  

The effect of Ti3C2Tx MXene etched at different temperatures (25 °C, 50 °C, and 80 °C) on the capacitance of supercapacitors without the use of conducting carbon-black or a binder was studied.


1957 ◽  
Vol 30 (1) ◽  
pp. 254-263
Author(s):  
T. S. McRoberts

Abstract The solubility of zinc oxide in solutions of ammonia and different ammonium salts has been determined. The interaction between ammonium laurate and zinc ammine (or ethylene diammine) salts has been studied in aqueous solution, in latex, and in oil emulsions. The results indicate that destabilization of ammoniated latex or soap-stabilized emulsions by dissolved zinc oxide is due to the presence of zinc diammine ions, which form insoluble dilaurates. It is suggested that the increased rate of destabilization at elevated temperatures is most probably due to a decrease in hydration of the zinc diammine dilaurate formed at the surface of the rubber or oil particles.


2015 ◽  
Vol 750 ◽  
pp. 339-344 ◽  
Author(s):  
Long Pan ◽  
Jin Zhu Tan ◽  
Liu Fei Fan ◽  
Xue Mei Han

Three kinds of reinforcing fillers (i.e. carbon black N330, carbon black N880 and carbon-white) were used to study effect of the reinforcing fillers on the mechanical properties of NBR materials. The NBR materials with various reinforcing fillers were fabricated, and the mechanical property tests were performed in this work. The results show that the carbon black N330 made the NBR material have better tensile strength, hardness, elongation and compression elastic modulus compared to the carbon black N880 and the carbon-white, while the carbon-white made NBR material have better heat resistance, tear strength and elongation compared to the carbon black N330 and the carbon black N880. In addition, the tensile strength, tear strength, elongation and the heat resistance property of the NBR materials increased significantly with the increase of the carbon-white, but the compression elastic modulus decreased with the increase of the carbon-white.


2019 ◽  
Vol 40 (1) ◽  
pp. 13-20
Author(s):  
Liu Yang ◽  
Kaikai Liu ◽  
Zijun Gu ◽  
Aihua Du

Abstract The aim of this study was to explore the impact of tension fatigue on the structure and properties of filled SBR and SBR/TPI blends. The effect of tension fatigue on the dynamic properties of carbon black-filled styrene-butadiene rubber (SBR) and SBR/trans-1,4-polyisoprene (SBR/TPI) blend vulcanizates were investigated by dynamic mechanical analysis (DMA). The Mooney-Rivlin analysis of tensile stress-strain data is used for the determination of a rubber network crosslink density. The fatigue fracture surface of SBR/TPI vulcanizates was observed with a scanning electron microscopy (SEM). The crystallinity of TPI in carbon black-filled SBR/TPI (80/20) was characterized by X-ray diffraction (XRD). The results showed that the incorporation of TPI into SBR vulcanizates influences the fatigue properties of the blend vulcanizates. The blend vulcanizates showed optimum fatigue properties with 20 phr TPI. With increasing fatigue cycles, the tensile properties and crosslink density of SBR vulcanizates were decreased substantially. Compared with that of SBR vulcanizates, the tensile properties and crosslink density of SBR/TPI (80/20) blend vulcanizates changed little with the increase in fatigue cycles, and tan δ and E′ decreased gradually with the fatigue cycles. There was a sharp decrease in the E′ and tan δ curve in the temperature range of 40 ~ 60°C. The XRD diffraction peak corresponding to 3.9 Å broadened when the fatigue cycles were increased to 1 million times, and a new peak with inter-planar spacing at 7.6 and 4.7 Å appeared.


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