Uncured Properties of Silica Filled ENR Compounds at High Temperature Curing

2014 ◽  
Vol 974 ◽  
pp. 102-106
Author(s):  
Mazlina Mustapha Kamal ◽  
Muhammad Zahid Zakaria
Keyword(s):  
High Temperature ◽  
Carbon Black ◽  
Natural Rubber ◽  
Physical Properties ◽  
Crosslink Density ◽  
Rolling Resistance ◽  
Curing Temperature ◽  
Rubber Mixture ◽  
Silica Filler ◽  
Work Effect

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.

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 ◽  
...  
Keyword(s):  
Carbon Black ◽  
Viscoelastic Properties ◽  
Crosslink Density ◽  
Rolling Resistance ◽  
Curing Temperature ◽  
Practical Application ◽  
Tire Industry ◽  
Bound Rubber ◽  
Increasing Demand ◽  
The Impact

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.

scholarly journals Loading Silica for Supporting Carbon Black Filler to Prevent Degradation Natural Rubber Caused DME

2021 ◽  
Vol 333 ◽  
pp. 13001
Author(s):  
Asep Handaya Saputra ◽  
Tuti Indah Sari ◽  
Dadi R. Maspanger ◽  
Setijo Bismo
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Filler Loading ◽  
High Permeability ◽  
Elongation At Break ◽  
Percentage Decrease ◽  
Silica Filler ◽  
Before And After

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.

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

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.

EFFECT OF DEVULCANIZATION ON CROSSLINK DENSITY AND CROSSLINK DISTRIBUTION OF CARBON BLACK FILLED NATURAL RUBBER VULCANIZATES

2016 ◽  
Vol 89 (4) ◽  
pp. 653-670 ◽  
Author(s):  
Anu Mary Joseph ◽  
Benny George ◽  
Madhusoodanan K. N. ◽  
Rosamma Alex
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Morphological Properties ◽  
Original Sample ◽  
Ambient Conditions ◽  
Absolute Value ◽  
Roll Mill ◽  
Percentage Retention ◽  
The Absolute

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.

Effect of vulcanization time on crosslink density and aging performance of natural rubber composites

2020 ◽  
Vol 62 (8) ◽  
pp. 858-862
Author(s):  
Ece Unur Yilmaz ◽  
Ahu Kor Dayioglu ◽  
Seda Balaban
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Operating Conditions ◽  
Rubber Composites ◽  
Rubber Mixture ◽  
Natural Rubber Composites ◽  
Different Temperatures ◽  
Auto Parts

Abstract Natural rubber composites are widely used in the automotive industry because of their improved viscoelastic characteristics that are mostly governed by crosslink density. However, rubber parts suffer deterioration of performance over long service lives. Therefore, optimization of crosslink density and prediction of changes in physico-mechanical properties over time at elevated temperatures is extremely important for the production of safe auto parts. In this work, the effect of vulcanization time on crosslink density and thus the performance and lifetime of natural rubberbased auto parts was investigated. The natural rubber mixture prepared in this context was vulcanized for 3, 5, 10 and 15 minutes at a constant temperature of 160 °C. The crosslink density of each vulcanizite was determined by equilibrium swelling tests and the Flory-Rehner equation. The maximum crosslink density (10.75 × 10-5 mol × cm-3) and the minimum permanent compression set values (10 % at 70 °C and 25 % at 100 °C) were recorded for the sample vulcanized for 10 minutes (v10). Aging behavior of the samples were investigated by stress relaxation tests performed at 85 °C, 100 °C and 120 °C. The service lives of the vulcanizites at different temperatures were predicted by linear Arrhenius fits of degradation times. The sample vulcanized for 10 minutes (v10) was shown to exhibit a service life of 2282 hours at 70 °C in air and the optimum physico-mechanical performance under real operating conditions. The performance and lifetime prediction procedure used in this work could be employed in an early design of rubber components for specific applications.

scholarly journals Silica-Reinforced Natural Rubber: Synergistic Effects by Addition of Small Amounts of Secondary Fillers to Silica-Reinforced Natural Rubber Tire Tread Compounds

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Sattayanurak ◽  
J. W. M. Noordermeer ◽  
K. Sahakaro ◽  
W. Kaewsakul ◽  
W. K. Dierkes ◽  
...  
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Dynamic Properties ◽  
Synergistic Effects ◽  
Coupling Reaction ◽  
Rolling Resistance ◽  
High Specific Surface Area ◽  
Pure Silica ◽  
Rubber Compounds ◽  
Wet Grip

Modern fuel-saving tire treads are commonly reinforced by silica due to the fact that this leads to lower rolling resistance and higher wet grip compared to carbon black-filled alternatives. The introduction of secondary fillers into the silica-reinforced tread compounds, often named hybrid fillers, may have the potential to improve tire performance further. In the present work, two secondary fillers organoclay nanofiller and N134 carbon black were added to silica-based natural rubber compounds at a proportion of silica/secondary filler of 45/10 phr. The compounds were prepared with variable mixing temperatures based on the mixing procedure commonly in use for silica-filled NR systems. The results of Mooney viscosity, Payne effect, cure behavior, and mechanical properties imply that the silica hydrophobation and coupling reaction of the silane coupling agent with silica and elastomer are significantly influenced by organoclay due to an effect of its modifier: an organic ammonium derivative. This has an effect on scorch safety and cure rate. The compounds where carbon black was added as a secondary filler do not show this behavior. They give inferior filler dispersion compared to the pure silica-filled compound, attributed to an inappropriate high mixing temperature and the high specific surface area of the carbon black used. The dynamic properties indicate that there is a potential to improve wet traction and rolling resistance of a tire tread when using organoclay as secondary filler, while the combination of carbon black in silica-filled NR does not change these properties.

Kinetics of Crosslinking and Network Changes in Natural Rubber Vulcanizates with a Dithiodimorpholine Based Accelerator System

1980 ◽  
Vol 53 (5) ◽  
pp. 1015-1022 ◽  
Author(s):  
A. K. Bhowmick ◽  
S. K. De
Keyword(s):  
Natural Rubber ◽  
Rate Constants ◽  
Crosslink Density ◽  
Curing Temperature ◽  
Side Reactions ◽  
Filler Surface ◽  
Natural Rubber Vulcanizates ◽  
Kinetics Of ◽  
Accelerator System

Abstract Kinetics of crosslinking and network changes in unfilled and filled natural rubber vulcanizates with a dithiodimorpholine based accelerator system have been studied at 150° and 180°C. Results show that addition of HAF black enhances the polysulfidic crosslinks as well as the total crosslinks. This has been explained with the help of Coran's model wherein HAK black increases the rate constants. It is likely that the filler surface prevents desulfuration and undesirable side reactions involving the crosslink precursors. Increase of curing temperature by 30°C lowers the total crosslink density and increases the sulfur inefficiency.

scholarly journals Influence of Carbon Black and Silica Filler on the Rheological and Mechanical Properties of Natural Rubber Compound

2015 ◽  
Vol 16 ◽  
pp. 258-264 ◽  
Author(s):  
Ika Maria Ulfah ◽  
Riastuti Fidyaningsih ◽  
Sri Rahayu ◽  
Diah Ayu Fitriani ◽  
Dita Adi Saputra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Natural Rubber ◽  
Rubber Compound ◽  
Silica Filler

Influence of Carbon Black on Crosslink Density of Natural Rubber

2012 ◽  
Vol 51 (6) ◽  
pp. 1208-1217 ◽  
Author(s):  
Zhao Fei ◽  
Chen Long ◽  
Pan Qingyan ◽  
Zhao Shugao
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Crosslink Density

Prototype of Geocell from Natural Rubber: Effect of Dual-Phase Fillers on Physical Properties of Rubber Compounds Reinforced with Silica and Carbon Black

2017 ◽  
Vol 737 ◽  
pp. 572-577
Author(s):  
Sompatsorn Wongwilatnurak ◽  
Surakit Tuampoemsab ◽  
Rapeephun Dangtungee
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Physical Properties ◽  
Mechanical Tests ◽  
Silica Content ◽  
Dual Phase ◽  
Chemical Formula ◽  
Tear Strength ◽  
The Road ◽  
Static Mechanical

Geocell, a type of the geosynthetics, is normally used to improve natural geomaterial properties and performance because of confinement and confinement force. This work was an attempt to apply the solid natural rubber (NR) for producing the prototype of geocell with reinforcing the pavement structure of the road. There are three parts of all work in research, which consist of finding the optimal chemical formula, designing and producing the prototype and civil engineering testing of flexible pavement components. This research has emphasized and focused on finding the optimal chemical formula for the prototype production. The effect of silica-carbon black (CB) dual-phase filler on physical properties in terms of only static mechanical tests of the prototype was investigated. The total amount of hybrid reinforcing filler was fixed at 60 phr while the silica/CB ratios were 0/60, 10/50, 20/40, 30/30 and 40/20, respectively. Cure characteristic of the NR compound and physical properties in terms of static mechanical tests such as hardness, tensile and tear strengths of the NR vulcanizates were carried out. The results showed that time to 90% cross-linked (TC 90), hardness and tensile strength of the vulcanized rubber were increased with the increasing of silica content but not for its tear strength. Dispersion of the dual-phase filler in the prototype was reduced when the higher amount of silica in the dual-phase filler was employed as proved by images from the scanning electron microscope. There was only 60 phr CB that was selected as the optimal chemical formula for prototype production as the result of tensile and tear strength.

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