Swelling Behavior of Rubbers Compounded with Reinforcing Pigments

1959 ◽  
Vol 32 (3) ◽  
pp. 825-843 ◽  
Author(s):  
B. B. S. T. Boonstra ◽  
Eli M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Fumed Silica ◽  
Crosslink Density ◽  
The Other ◽  
Rubber Matrix ◽  
Volume Loading ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
Equilibrium Swelling ◽  
The Matrix

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.

Application of the Measurement of the Dielectric Constant and Loss Angle to the Study of the Structure of Vulcanizates Loaded with Carbon Blacks

1952 ◽  
Vol 25 (3) ◽  
pp. 533-548
Author(s):  
P. Thirion ◽  
R. Chasset
Keyword(s):  
Dielectric Constant ◽  
Carbon Black ◽  
The Other ◽  
Rubber Matrix ◽  
Loss Angle ◽  
Colloidal Structure ◽  
Dielectric Absorption ◽  
Dielectric Loss Angle ◽  
Dielectric Constant And Loss ◽  
The Matrix

Abstract In the case of vulcanizates containing carbon black the variation curves of dielectric loss angle as a function of temperature enable the Debye type absorption occurring in the rubber matrix to be distinguished from a supplementary absorption little influenced by variations in temperature and frequency which is characteristic of blacks possessing a structure. The experimental results obtained indicate no difference in physical or chemical state between the matrix occupying the space between the particles of black in a loaded mix and the vulcanizate of the corresponding pure rubber mix. The supplementary losses on the other hand seem to be closely related to the effects of structure in loaded mixes imagined by Mullins to explain the mechanical behavior of these mixes: they decrease very rapidly by elongation or swelling and give rise to various phenomena of hysteresis. It would seem that dielectric absorption could advantageously be applied as a nondestructive test revealing the colloidal structure of rubber mixes based on carbon black. Moreover the dielectric constant would enable information to be obtained on the form factor and the orientation of the particles or agglomerates of particles of black in mixes on the basis of a theory assimilating these particles (or agglomerates) to condenser armatures.

Filler—Elastomer Interactions. Part IV. The Effect of the Surface Energies of Fillers on Elastomer Reinforcement

1992 ◽  
Vol 65 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Siegfried Wolff ◽  
Meng-Jiao Wang
Keyword(s):  
Carbon Black ◽  
Small Strain ◽  
Rubber Content ◽  
Specific Component ◽  
Dispersive Component ◽  
Surface Energies ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
High Elongation ◽  
Polymer Interaction

Abstract Carbon black N110 and a precipitated silica, which have comparable surface area and structure, were selected as model fillers to study the effect of filler surface energies on rubber reinforcement. In comparison with carbon black, the surface energies of silica are characterized by a lower dispersive component, γsd, and higher specific component, γssp. It was found that the high γssp of silica leads to strong interaggregate interaction, resulting in higher viscosity of the compounds, higher αƒ, and higher moduli of the vulcanizates at small strain. The higher γsd of carbon black, in contrast, causes strong filler—polymer interaction, which is reflected in a higher bound-rubber content of the compounds and higher moduli of the vulcanizates at high elongation.

Reinforcing Effect of Silica and Silane Fillers on the Properties of Some Natural Rubber Vulcanizates

2003 ◽  
Vol 76 (5) ◽  
pp. 1290-1310 ◽  
Author(s):  
A. Ansarifar ◽  
R. Nijhawan ◽  
T. Nanapoolsin ◽  
M. Song
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Cyclic Fatigue ◽  
Rubber Matrix ◽  
Stored Energy ◽  
Elongation At Break ◽  
Reinforcing Effect ◽  
Bound Rubber ◽  
Technical Properties ◽  
Natural Rubber Vulcanizates

Abstract The reinforcing effect of up to 6 parts per hundred rubber by weight (phr) bis- (3-triethoxysilylpropyl) tetrasulfide (TESPT), a bifunctional organosilane, on the crosslink density, bound rubber, and technical properties of some conventional accelerator/sulfur compounds of natural rubber, containing 30 phr precipitated amorphous white silica was studied. The crosslink density and bound rubber improved as a function of TESPT loading. The tensile strength, elongation at break, stored energy density at rupture, and cohesive tear strength deteriorated at low loading of TESPT, but they subsequently increased after the full amount of TESPT was introduced into the compound. The improved properties of the vulcanizate was due to the better dispersion of the filler in the rubber matrix. However, the cyclic fatigue life was adversely affected, and the hardness hardly changed as a result of adding TESPT to the rubber.

Some Effects of Solid Fillers in Rubbers

1953 ◽  
Vol 26 (1) ◽  
pp. 156-165
Author(s):  
Ira Williams
Keyword(s):  
Tensile Strength ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Abrasion Resistance ◽  
Volume Loading ◽  
Rubber Compounds ◽  
Before And After ◽  
The Matrix ◽  
The Many ◽  
Tear Resistance

Abstract The presence of pigments in rubber compounds produces physical properties which are of importance both before and after vulcanization. The ability of the unvulcanized mixture to calender or extrude smoothly with minimum swelling and to maintain shape during air cures, and the tensile strength, tear resistence, and abrasion resistance of vulcanized stocks all are affected. The methods by which these changes are brought about have been considered by many investigators and have been summarized by Parkinson1 and by Shepard, Street, and Park. Since carbon black is the most generally useful reinforcing pigment, it is natural that investigations have been directed particularly to this product. However, while it is recognized that differences exist in the final properties imparted by different pigments, all solid compounding ingredients have something in common. This point can be illustrated by the tear resistance imparted by such a variety of pigments as carbon black, zinc oxide, whiting, and clay. The effect of volume loading on the tear resistance of vulcanized stocks containing these materials, determined by the method of Zimmerman is shown in Figure 1. The effect of solid compounding ingredients can be studied only by considering the compound as a whole, since the properties are determined very largely by the relation between the solid particle and the matrix which surrounds it. Since the introduction of the many types of synthetic rubbers, the complexity of the problem has been greatly increased by the different states of polymerization, which affect the ability of the rubber to conform to the shape of the pigment particle and by the differences in polar nature which affect the type and the degree of adhesion between filler and matrix.

Online Electrical Conductivity as a Measure to Characterize the Carbon Black Dispersion in Oil Containing Rubber Compounds with a Different Polarity of Rubber

2004 ◽  
Vol 77 (5) ◽  
pp. 815-829 ◽  
Author(s):  
H. H. Le ◽  
I. Prodanova ◽  
S. Ilisch ◽  
H.-J. Radusch
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Conductivity Measurement ◽  
Infiltration Rate ◽  
Rubber Matrix ◽  
Electrical Conductivity Measurement ◽  
Infiltration Process ◽  
The Matrix ◽  
Polar Oil ◽  
Carbon Black Dispersion

Abstract The influence of viscosity, polarity of the rubber matrix and the types and contents of extender oil on the carbon black dispersion has been characterized using the online electrical conductivity measurement. A corresponding change of the online conductivity with the rubber infiltration and extent of carbon black dispersion has been observed. The infiltration rate increases with increasing polarity and decreasing viscosity of the rubber matrix, whereby the matrix polarity shows a stronger effect than the viscosity. The oil addition accelerates the infiltration process. This is caused by the reduction of the matrix viscosity and the intensification of the filler-matrix interaction. Oil addition affects the carbon black dispersion in non-polar rubber much more than in polar rubber. Furthermore, in non-polar rubber, polar oil shows a stronger effect than non-polar oil.

A Method for Evaluation of Carbon Blacks and Correlation with Road Wear Ratings

1974 ◽  
Vol 2 (3) ◽  
pp. 211-228 ◽  
Author(s):  
G. R. Cotten ◽  
E. M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Abrasion Resistance ◽  
Laboratory Tests ◽  
The Other ◽  
Rubber Content ◽  
Carbon Blacks ◽  
Heat Treated ◽  
Bound Rubber ◽  
Normal Production

Abstract Prediction of tread wear from laboratory tests can be a valuable guide in the development of improved carbon blacks and controlling the quality of normal production. We have developed two tests which give good correlation with actual road wear data on over 100 experimental blacks. One test involves running Akron angle abrasion on a compound with only 30 phr of carbon black where differences in abrasion resistance are magnified. The other test measures surface activity towards the polymer by determining bound rubber content of a heat-treated nonproductive mix. By using both tests together, tread wear ratings of blacks used in this study could be predicted almost as well as by a single, controlled, multisectional road test with five tires run for 8000–10,000 miles.

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.

Characterization of Polymer Adsorption on Disordered Filler Surfaces by Transversal 1H NMR Relaxation

1997 ◽  
Vol 70 (5) ◽  
pp. 747-758 ◽  
Author(s):  
H. Lüchow ◽  
E. Breier ◽  
W. Gronski
Keyword(s):  
Surface Roughness ◽  
Carbon Black ◽  
1H Nmr ◽  
Nmr Relaxation ◽  
Rubber Matrix ◽  
Adsorption Sites ◽  
Bound Rubber ◽  
Carbon Black Surface ◽  
Black Surface ◽  
Tan Δ

Abstract The transversal 1H NMR relaxation of the bound rubber shell of carbon black loaded elastomers can be decomposed into three relaxation regimes corresponding to the loosely bound rubber, the rubber that is immobilized on the carbon black surface and a third component of intermediate mobility. The relaxation time T2 of the intermediate component is related to the end-to-end distance of polymer segments between adsorption sites on the carbon black surface, by converting the relaxation times to length scales on the basis of recent work on NMR relaxation of elastomeric networks. From measurements on SBR loaded with carbon black N 220, a distance of 2.3 nm was obtained in agreement with characteristic dimensions of crystallite sizes and surface roughness as determined by atomic force and scanning tunneling microscopy. The analysis was applied to novel inversion blacks which give lower tan δ/60°C, and rolling resistance without affecting tan δ/0°C and wet skid behavior. These blacks were found to possess a higher density of adsorption sites and a greater surface roughness as compared to standard carbon blacks. In addition to the surface characterization, the analysis of the mobile component of the compound allowed the estimation of the density of entanglement couplings between the rubber matrix and the bound rubber shell.

Mixing time influence on fatigue crack growth in a carbon black-filled natural rubber vulcanizate

2019 ◽  
Vol 36 (2) ◽  
pp. 115-130
Author(s):  
Harini Sridharan ◽  
Jagannath Chanda ◽  
Prasenjit Ghosh ◽  
Rabindra Mukhopadhyay
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Carbon Black ◽  
Crack Growth ◽  
Mixing Time ◽  
Processing Parameters ◽  
Rubber Matrix ◽  
Mixing Times ◽  
Bound Rubber ◽  
The Difference

Various processing parameters affect the dispersion of carbon black (CB) in a rubber matrix, of which mixing time plays a major role. The physical properties of a green compound namely bound rubber and Mooney viscosity along with mechanical and fatigue crack growth (FCG) are affected by the dispersion of filler particles. To determine the effect of mastication on dispersion, the mixing time was varied from 120 s to 600 s where it was gauged that an optimum range of mixing times display better dispersion. The difference in dispersion between the green and the cured compounds was also stark due to the flocculation mechanism. Longer mixing times do not show much decrease in agglomerate size on curing, that is, approximately 2%, whereas shorter time has led to a decrease of 20%. The FCG properties were studied using a tear and fatigue analyser, where the FCG rate displays a similar trend with the dispersion of CB.

Limiting Law of the Reinforcement of Rubber

1945 ◽  
Vol 18 (2) ◽  
pp. 292-305 ◽  
Author(s):  
Hugh M. Smallwood
Keyword(s):  
Molecular Structure ◽  
Experimental Data ◽  
Particle Size ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Filler Particle ◽  
Rubber Matrix ◽  
Volume Loading ◽  
Volume Percentage ◽  
Filler Particles

Abstract 1. Analysis shows that, subject to certain limitations, the modulus of a loaded stock (M*) depends on the modulus of the rubber matrix (M), according to the equation: M*=M(1+2.5ϕ) where 100ϕ is the volume percentage of filler. When these limitations are fulfilled, the effect of compounding on modulus is, therefore, independent of the particle size of the filler. The assumptions on which this equation is founded are as follows: (1) the filler particles are spherical; (2) there is complete adhesion between rubber and filler; (3) the elongation is small; (4) the filler is completely dispersed; (5) the volume loading is small; (6) the filler particles are sufficiently large that the molecular structure of the rubber may be neglected. 2. The stresses about a filler particle have been derived mathematically. 3. Experimental data check the calculations for the following fillers: P-33, Thermax, and whiting. Catalpo clay presents some anomalies because of its acicular particles. 4. Carbon black does not conform to the calculations. This is attributed to the fact that it is strongly flocculated in rubber. 5. Zinc oxide (Kadox or XX zinc oxide), which should conform, because it is well dispersed in rubber, causes abnormally large increases in modulus, presumably because of alteration of the type of cure and consequent alteration of the modulus of the rubber matrix.

Sign in / Sign up

Export Citation Format

Share Document