scholarly journals Vulcanizate Structures of SBR Compounds with Silica and Carbon Black Binary Filler Systems at Different Curing Temperatures

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2343
Author(s):  
Il Jin Kim ◽  
Donghyuk Kim ◽  
Byungkyu Ahn ◽  
Hyung Jae Lee ◽  
Hak Joo Kim ◽  
...  

The tire industry has shown an increasing demand for the reduction in rolling resistance. Efforts have been made to improve the viscoelastic properties of tire compounds and reduce the weight of tires through optimization of the vulcanizate structure, which has become extremely complex. In this study, vulcanizates using carbon black and silica as binary fillers were prepared at various curing temperatures. Vulcanizate structures with respect to curing temperature were classified according to the chemical crosslink density by sulfur, carbon black bound rubber (i.e., physical crosslink due to carbon black), and silica-silane–rubber network. All properties exhibited a decreasing trend under the application of high curing temperatures, and the decrease in the crosslink density per unit content of filler with an increase in curing temperature was shown to be greater in carbon black than in silica. Mechanical and viscoelastic properties were also measured to evaluate the impact that the compound variates have on tire tread performance. These results serve as a guideline for determining the content and filler type and for setting the cure condition during the design of actual compound formulations to increase the crosslink density of rubber while retaining the necessary mechanical and viscoelastic properties for practical application.

2014 ◽  
Vol 974 ◽  
pp. 102-106
Author(s):  
Mazlina Mustapha Kamal ◽  
Muhammad Zahid Zakaria

Rubber reinforcement in general depends on the type of filler used in the rubber mixture. Instead of carbon black, Silica filler has been widely accepted in tyre making due to its low rolling resistance property. In recent years, there is a trend in using higher curing temperature in order to improve productivity of vulcanisation line without drawbacks in the performance of tyres. In this work, effect of vulcanisation temperature based on the silica filled ENR curing behaviour was studied. Results indicate that time-dependant reversion behaviour of ENR was similar to that of unmodified Natural Rubber. The physical properties slowly deteriorated as the curing temperature approached 180°C which related to low crosslink density. Carbon Black filled ENR compound was used as a comparison.


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.


2021 ◽  
Vol 30 ◽  
pp. 263498332110054
Author(s):  
Rungsima Chollakup ◽  
Supitta Suethao ◽  
Potjanart Suwanruji ◽  
Jirachaya Boonyarit ◽  
Wirasak Smitthipong

The effects of carbon black on the properties of rubber composites were studied in order to explore their value in producing low rolling resistance truck tires. Carbon black with different grades, N330 (coarser grade of 26–30 nm) and N220 (finer grade of 20–25 nm), was used as a reinforcing agent of natural rubber. The effects of different ratios of carbon black N330 at 40, 45, 50 and 55 parts per hundred rubber (phr) and N220 at 30, 35, 40 and 50 phr were investigated. Rubber composites with N220 had greater rubber/carbon black interaction than those with N330. The Mooney viscosity of rubber composite increased when the carbon black ratio increased. After vulcanisation of rubber, the samples were characterised by dynamic mechanical analysis, tensile strength and heat build-up. The results showed that the strength of rubber composites increased with increasing carbon black ratios. Interestingly, at the same bound rubber level, rubber composites with N220 presented lower dissipation energy, heat build-up and better mechanical properties than those with N330. This study indicated that reinforcement with an optimum amount of carbon black N220 would improve several desirable characteristics of rubber composites when used in low rolling resistance truck tires.


1959 ◽  
Vol 32 (3) ◽  
pp. 825-843 ◽  
Author(s):  
B. B. S. T. Boonstra ◽  
Eli M. Dannenberg

Abstract Equilibrium swelling data are presented for vulcanizates of natural rubber, SBR 1500, butyl rubber, neoprene, and nitrile rubber containing fumed silica, precipitated silica, precipitated calcium metasilicate, hard clay and carbon black. Swelling media are chloroform, benzene, hexane, and acetone. It is observed that certain fillers, particularly carbon black, cause a reduction in the swelling of the rubber matrix which is commensurate with the volume loading of the filler. This effect is not specific for a particular solvent or elastomer. When a series of loadings of a filler shows this effect of reducing the matrix swelling in one solvent, it is also shown by the swelling data for the other solvents, but not to the same degree. The system SBR-benzene was studied to determine from the bound rubber measurements and the equilibrium swelling data for the corresponding vulcanizates the number of crosslinks per cubic centimeter in the unvulcanized and vulcanized states. It appears that the number of crosslinks estimated in the bound rubber gel is much too small to account for the increase in crosslink density in the rubber matrix that is caused by the presence of carbon black in the vulcanizate.


1972 ◽  
Vol 45 (1) ◽  
pp. 94-105 ◽  
Author(s):  
J. J. Brennan ◽  
D. H. Lambert

Abstract The crosslink density of vulcanizates has been quantitatively investigated using swelling measurements (Vr) of compounds of cis-1,4-polybutadiene reinforced with N242, N326, or N990 (Vulcan 6H, Regal 300, Sterling MT). Crosslink density in both filled and unfilled stocks is shown to be related to the molar concentration of the curatives in the unbound rubber phase of the vulcanizates and not merely to total concentration. The effects of different carbon black loadings and of cure time are demonstrated to be fully describable by the extent of carbon black—rubber interaction, measured by bound rubber; that occurs during mixing and during the induction period of the cure step. Greater rubber-black interaction, whether achieved by higher black level or from higher reinforcing blacks, always yielded vulcanizates of increased crosslink density compared to an identically vulcanized gum control. Calculating curative concentration on the basis of unbound rubber—rather than total rubber—illustrated the expected dependence of crosslink density upon curative concentration and graphically explains the presence of so-called “excess” crosslinks. Implied, also, is one cause for the “scorchy” character of highly reinforcing blacks and the higher modulus obtained with these blacks.


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.


2020 ◽  
Vol 2020 (10) ◽  
pp. 19-33
Author(s):  
Nadiia NOVYTSKA ◽  
◽  
Inna KHLIEBNIKOVA ◽  

The market of tobacco products in Ukraine is one of the most dynamic and competitive. It develops under the influence of certain factors that cause structural changes, therefore, the aim of the article is to conduct a comprehensive analysis of transformation processes in the market of tobacco and their alternatives in Ukraine and identify the factors that cause them. The high level of tax burden and the proliferation of alternative products with a potentially lower risk to human health, including heating tobacco products and e-cigarettes, are key factors in the market’s transformation process. Their presence leads to an increase in illicit turnover of tobacco products, which accounts for 6.37% of the market, and the gradual replacement of cigarettes with alternative products, which account for 12.95%. The presence on the market of products that are not taxed or taxed at lower rates is one of the reasons for the reduction of excise duty revenues. According to the results of 2019, the planned indicators of revenues were not met by 23.5%. Other reasons for non-fulfillment of excise duty revenues include: declining dynamics of the tobacco products market; reduction in the number of smokers; reorientation of «cheap whites» cigarette flows from Ukraine to neighboring countries; tax avoidance. Prospects for further research are identified, namely the need to develop measures for state regulation and optimization of excise duty taxation of tobacco products and their alternatives, taking into account the risks to public health and increasing demand of illegal products.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Mathilde Tiennot ◽  
Davide Iannuzzi ◽  
Erma Hermens

AbstractIn this investigation on the mechanical behaviour of paint films, we use a new ferrule-top nanoindentation protocol developed for cultural heritage studies to examine the impact of repeated relative humidity variations on the viscoelastic behaviour of paint films and their mechanical properties in different paint stratigraphies through the changes in their storage and loss moduli. We show that the moisture weathering impact on the micromechanics varies for each of these pigment-oil systems. Data from the nanoindentation protocol provide new insights into the evolution of the viscoelastic properties dsue to the impact of moisture weathering on paint films.


2021 ◽  
pp. 009524432110290
Author(s):  
Leandro Hernán Esposito ◽  
Angel José Marzocca

The potential replacement of a treated residual aromatic extract mineral oil (TRAE) by a highly epoxidized soybean oil (ESO) into a silica-filled styrene-butadiene rubber compound was investigated. In order to determine if ESO compounds performance are suitable for tread tire applications, processing properties cure and characteristics were evaluated. The impact of ESO amount on the silica dispersion was confirmed by Payne Effect. The presence of chemical or physical interactions between ESO and silica improves the filler dispersion, enabling the compound processability and affecting the cure kinetic rate. An adjusted rubber compound with 2 phr of ESO and 2 phr of sulfur presented the higher stiffness and strength values with lower weight loss from a wear test compared with TRAE compound at an equal amount of oil and curing package. Furthermore, wet grip and rolling resistance predictors of both compounds gave comparable results, maintaining a better performance and reducing the dependence of mineral oil for tire tread compounds.


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