Relationships of tensile strength with crosslink density for the high‐carbon black‐filled EPDM compounds with various softeners

Author(s):  
Jieyun Tu ◽  
Xinghui Shi ◽  
Yuanrong Jing ◽  
Huimin Zou ◽  
Jakub Kadlcak ◽  
...  
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.


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.


2021 ◽  
Vol 333 ◽  
pp. 13001
Author(s):  
Asep Handaya Saputra ◽  
Tuti Indah Sari ◽  
Dadi R. Maspanger ◽  
Setijo Bismo

DME (Dimethyl Ether) is the future environmental friendly fuel. Some parts of equipment for transporting the DME are using rubber as a hoses or seals. This research is about the using of natural rubber for those applications. The influential part in the manufacture of natural rubber products are fillers. The use of filler depends on what the product will be made. DME nature have high permeability and easy to absorb into a rubber and plastic. In such of that, the rubber or plastic could be damaged and not durable. In order to determine the type of degradation, the number of samples were immersed in liquid DME. The ratio of the loading of carbon black/silica filler in natural rubber was varied. DME causes two types of degradation, namely absorption and extraction. The addition of filler composition can reduce the absorption and extraction, which can cause a reduction in the percentage decrease in the value of the change in mass and a decrease in tensile strength. On the other hand, the addition of filler composition will increase the changes of hardness. The higher filler loading, will increase the crosslink density and lower scorch time. The presence of silica further is to enhance the crosslink density as well as to lower scorch time. Therefore, the presence of silica affect on the decreasing of the swelling level and shrinking. In general, the presence of silica filler in the mixture will be slightly lowering the tensile strength, but not affecting the elongation at break. The presence of silica before and after soaking with DME will increase hardness.


2020 ◽  
Vol 837 ◽  
pp. 74-80
Author(s):  
Jun Yuan ◽  
Zhen Yu Han ◽  
Yong Deng ◽  
Da Wei Yang

In view of the special requirements of rails to ensure the safe and stable operation of Railways in China, the formation characteristics of austenite grains in high carbon rail are revealed through industrial exploration, the process of industrial rail heating and rolling is simulated, innovative experimental research methods such as different heating and heat treatment are carried out on the actual rails in the laboratory. Transfer characteristics of austenite grain size, microstructures and key properties of high carbon rail during the process are also revealed. The results show that the austenite grain size of industrial produced U75V rail is about 9.0 grade. When the holding temperature is increased from 800 C to 1300 C, the austenite grain size of high carbon rail steel decreases, the austenite grain are gradually coarsened, and the tensile strength increases slightly. The tensile strength is affected by the heating temperature. With the increase of heating temperature, the elongation and impact toughness of high carbon rail decrease. The heating temperature of high carbon rail combined with austenite grain size shows that the heating temperature has a great influence on austenite grain size, and has the most obvious influence on the toughness of high carbon rail.


1993 ◽  
Vol 66 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Asahiro Ahagon

Abstract Analysis is made for the origin of the mixing-induced tensile property variation of a filled rubber. Attention is paid to the hydrodynamic effect f(ϕe) of the filler, defined here as the factor to adjust the deviation of 100% modulus from the theory of rubber elasticity. For the rubbers mixed under variety of conditions, the f(ϕe)'s are calculated from the observed values of the modulus, at 25°C and 100°C, and the crosslink density. The variation of the f(ϕe) is considered to be governed by the mobility of the polymer confined in agglomerates of the filler. The mobility variation due to mixing seems to be mainly influenced by agglomerate size at 25°C, and by agglomerate size and chemical constraints at 100°C. Therefore, the f(ϕe)'s at the two temperatures are suggested to be useful measures of the state of carbon-black micro-dispersion. The extensibility of the rubbers is closely related f(ϕe). This indicates that the failure property is also governed by the mobility of the confined polymer.


1944 ◽  
Vol 17 (2) ◽  
pp. 451-474
Author(s):  
D. Parkinson

Abstract Carbon blacks can be grouped into different classes according to the way in which their fineness of division relates to different properties in rubber. Within any one class the principal properties vary in a regular manner with particle size. The normal class consists of the furnace carbons, Kosmos (Dixie)-40, Statex, the rubber-grade impingement carbons, and possibly, the color-grade impingement carbons. The subnormal classes consist of thermal carbons and acetylene and lamp blacks. Irrespective of the above classification, the properties which depend more on fineness of division than on other factors are rebound resilience, abrasion resistance, tensile strength and tear resistance. The lower limit of particle diameter for best tensile strength and tear resistance appears to be higher than that for abrasion resistance. B.S.I, hardness and electrical conductivity are properties which depend at least as much on other factors as on particle size. Stiffness (modulus) depends more on other factors than on particle size. Factors modifying the effects of particle size (or specific surface) include the presence of carbon-carbon structures and a reduction in strength of bond in rubber-carbon structures. Carbon black is thought to exist in rubber in four states: agglomerated, flocculated, dispersed, and bonded to the rubber molecules (the reënforcing fraction). Abrasion resistance is regarded as providing the only reliable measure of reënforcement.


2021 ◽  
Vol 2 (108) ◽  
pp. 75-85
Author(s):  
Q.H. Jebur ◽  
M.J. Jweeg ◽  
M. Al-Waily ◽  
H.Y. Ahmad ◽  
K.K. Resan

Purpose: Rubber is widely used in tires, mechanical parts, and user goods where elasticity is necessary. Some essential features persist unsolved, primarily if they function in excessive mechanical properties. It is required to study elastomeric Rubber's performance, which is operational in high-level dynamic pressure and high tensile strength. These elastomeric aims to increase stress breaking and preserve highly pressurised tensile strength. Design/methodology/approach: The effects of carbon black polymer matrix on the tensile feature of different Rubber have been numerically investigated in this research. Rubber's material characteristics properties were measured using three different percentages (80%, 90%and 100%) of carbon black filler parts per Hundreds Rubber (pphr). Findings: This study found that the tensile strength and elongation are strengthened as the carbon black filler proportion increases by 30%. Practical implications: This research study experimental tests for Rubber within four hyperelastic models: Ogden's Model, Mooney-Rivlin Model, Neo Hooke Model, Arruda- Boyce Model obtain the parameters for the simulation of the material response using the finite element method (FEM) for comparison purposes. These four models have been extensively used in research within Rubber. The hyperelastic models have been utilised to predict the tensile test curves—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model. Numerical Ogden model results have shown that the relative fitness error was the case with large strains are from 1% to 2.04%. Originality/value: In contrast, other models estimate parameters with fitting errors from 2.3% to 49.45%. The four hyperelastic models were tensile test simulations conducted to verify the efficacy of the tensile test. The results show that experimental data for the uniaxial test hyperelastic behaviour can be regenerated effectively as experiments. Ultimately, it was found that Ogden's Model demonstrates better alignment with the test data than other models.


1982 ◽  
Vol 55 (4) ◽  
pp. 1137-1151 ◽  
Author(s):  
R. R. Campbell ◽  
D. A. Stivers ◽  
R. E. Kolb

Abstract The effects of percent fluorine, filler, and cure systems on the thermal and acid resistance of fluoroelastomers were evaluated over temperature ranges that would be typical of actual flue duct installations and accelerated conditions such as 275°C for thermal resistance and 149°C for concentrated sulfuric acid resistance. FKM 2176, which contains 65% fluorine by weight, became hard and brittle after two weeks of accelerated air aging at 275°C. The balance of physical properties of FKM 2176 were good when aged at 200°C. FKM 4894, which contains 67% fluorine by weight, retained useful properties after six weeks of accelerated air aging at 275°C. This indicates this material has improved properties for flue duct applications compared to FKM 2176. FKM 4894 filled with MT carbon black had improved retention of tensile strength after aging at 232°C relative to the FKM 4894 filled with SRF/HAF black, Austin Black and litharge. FKM 2176 was totally degraded after aging three days at 149°C in concentrated sulfuric acid. Aging of FKM 4894 in concentrated sulfuric acid at 149°C resulted in a loss of approximately 75 percent of the original tensile and an increase in the elongation, and the appearance of the exposed surface did not indicate chemical attack. Although FKM 4894 was superior to FKM 2176 when aged in sulfuric acid at 149°C, there was little difference between FKM 4894 and FKM 2176 when aged at 121 °C for up to four weeks or after eight weeks at 100°C in concentrated sulfuric acid. Austin Black showed the best retention of tensile of the four filler systems evaluated after aging at 100°C in concentrated sulfuric acid. FKM 4826, which contains 69% fluorine and is vulcanized using organic peroxide and triallyl isocyanurate, has indicated a compatibility with fiberglass that is superior to all fluorocarbon elastomer gums that were tested.


2016 ◽  
Vol 89 (4) ◽  
pp. 653-670 ◽  
Author(s):  
Anu Mary Joseph ◽  
Benny George ◽  
Madhusoodanan K. N. ◽  
Rosamma Alex

ABSTRACTCarbon black filled natural rubber (NR) vulcanizates were devulcanized at ambient temperature in a two roll mill. The effect of cure system, that is, conventional vulcanization (CV), semiefficient vulcanization (semi EV), and efficient vulcanization (EV) systems, used for vulcanization of the original sample, on the efficiency of devulcanization was studied. The efficiency of devulcanization expressed as percentage devulcanization of the samples calculated from residual crosslink density measurements was correlated with the sol fraction of the devulcanized samples based on Horikx analysis. Using chemical probe analysis, we determined (i) the crosslink distribution pattern of the original sample, (ii) the extent to which the different types of crosslinks—that is, polysulfidic, disulfidic, and monosulfidic crosslinks—have been debonded or broken during the shearing process in the two roll mill, and (iii) the pattern of bond formation during revulcanization. Mechanical shearing predominantly breaks the majority crosslink type (polysulfidic crosslinks in CV and semi EV cure systems and disulfidic crosslinks in EV samples). Irrespective of the significant reduction in total crosslink density in all three sets of samples, chain shortening reactions similar to the post-crosslinking chemical reactions at curing temperatures also occur during mechanical shear at ambient conditions, which increased the absolute value of monosulfidic links in CV and semi EV systems. However, in the devulcanized EV system, the absolute value of polysulfidic crosslinks increased, which might be due to the re-crosslinking of the cleaved bonds. All the devulcanized samples were revulcanized, and the mechanical and morphological properties were analyzed. The percentage retention of the vulcanizate properties after revulcanization of the devulcanized samples correlated very well with efficiency of devulcanization.


2018 ◽  
Vol 34 ◽  
pp. 01030 ◽  
Author(s):  
Indra Surya ◽  
Syahrul Fauzi Siregar ◽  
Hanafi Ismail

Effects of alkanolamide (ALK) addition on cure characteristics, swelling behaviour and tensile properties of silica-filled natural rubber (NR)/chloroprene rubber (CR) blends were investigated. The ALK was synthesized from Refined Bleached Deodorized Palm Stearin (RBDPS) and diethanolamine, and incorporated into the silica-filled NR/CR blends as a non-toxic rubber additive. The ALK loadings were 0.0, 1.0, 3.0, 5.0 and 7.0 phr. It was found that the ALK exhibited shorter scorch and cure times and higher elongation at break of the silica-filled NR/CR blends. The ALK also exhibited higher torque differences, tensile modulus and tensile strength at a 1.0 phr of ALK loading and then decreased with further increases in the ALK loading. The swelling measurement proved that the 1.0 phr loading of ALK caused the highest degree in crosslink density of the silica-filled NR/CR blends.


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