Prediction of Bound-Rubber Modulus by Clausius—Mossotti Approximation

1990 ◽  
Vol 63 (4) ◽  
pp. 523-539 ◽  
Author(s):  
J. J. Scobbo

Abstract The Clausius—Mossotti approximation has been used to determine the modulus of bound rubber attached to carbon black in a gum-rubber/carbon-black compound. The effective hydrodynamic concentration of the carbon-black/bound-rubber structure was first determined based on the assumption of spherical filler particles with a uniform layer of bound rubber on the surface. The true carbon-black concentration was then subtracted from this concentration, and a three component modeling scheme was used. The three components were considered to be bound-rubber, carbon black, and gum-rubber matrix. The Clausius—Mossotti approximation was used to determine the bound-rubber modulus that would give the same compound modulus based on equivalent hydrodynamic volume. Results indicate that bound-rubber concentration decreases with increasing strain. At zero strain, the bound-rubber concentration is approximately equal to the carbon-black concentration. Modulus values of bound rubber were found to be 3 to 4 times greater than gum-modulus values at very low strains. The relatively greater magnitude of bound-rubber modulus decreased with increasing strain until the filler effect appears to be almost purely hydrodynamic. The electromagnetic theory-based Clausius—Mossotti model was found to predict bound-rubber moduli that were in agreement with a mechanical model, the Kerner model.

1995 ◽  
Vol 68 (4) ◽  
pp. 652-659 ◽  
Author(s):  
S. Maas ◽  
W. Gronski

Abstract The changes of the filler morphology of SBR vulcanizates loaded with 10 phr carbon black (N234 and N990) subjected to large strains were studied by Atomic Force Microscopy and image analysis. It was found that the filler particles tend to align in the force field. The average distance of the filler particles at the surface in the direction parallel and perpendicular to the strain direction is much smaller then according to affine deformation. The measurements give evidence of the inhomogeneous deformation of the rubber matrix and demonstrate the onset of failure at large deformation.


1997 ◽  
Vol 70 (5) ◽  
pp. 747-758 ◽  
Author(s):  
H. Lüchow ◽  
E. Breier ◽  
W. Gronski

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.


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.


2019 ◽  
Vol 36 (2) ◽  
pp. 115-130
Author(s):  
Harini Sridharan ◽  
Jagannath Chanda ◽  
Prasenjit Ghosh ◽  
Rabindra Mukhopadhyay

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.


1945 ◽  
Vol 18 (2) ◽  
pp. 292-305 ◽  
Author(s):  
Hugh M. Smallwood

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.


1999 ◽  
Vol 72 (5) ◽  
pp. 862-875 ◽  
Author(s):  
D. Trifonova-Van Haeringen ◽  
H. Schönherr ◽  
G. J. Vancso ◽  
L. van der Does ◽  
J. W. M. Noordermeer ◽  
...  

Abstract The microdispersion of silica and carbon black-based filler particles in unvulcanized and vulcanized ethylene-propylene-diene terpolymer (EPDM) rubbers was investigated by atomic force microscopy (AFM). Tapping mode phase imaging was found to be particularly useful for imaging of the filler aggregates and for the visualization of single primary filler particles. It was demonstrated that the use of silane coupling agents significantly improves the microdispersion of silica filler in the rubber matrix, as compared to (a) silica without coupling agent, and (b) to carbon black. These results correlate very well with the observed mechanical properties of the materials. In addition, adhesion imaging and the analysis of measured pull-off forces allowed us to differentiate between the filler particles and the rubber matrix, as well as between different types of filler particles. The application of chemically modified AFM tips in pull-off force measurements allowed us to monitor the increase of the hydrophilicity as a result of plasma treatment of the surface of crosslinked poly(dimethylsiloxane), and as a result of chlorination of butyl rubber.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.


2021 ◽  
pp. 0734242X2110047
Author(s):  
Junqing Xu ◽  
Jiaxue Yu ◽  
Wenzhi He ◽  
Juwen Huang ◽  
Junshi Xu ◽  
...  

Pyrolysis offers a more focused alternative to waste tyres treatment. Pyrolytic carbon black (CBp), the main product of waste tyre pyrolysis, and its modified species can be applied to tyre manufacturing realizing its high-value utilization. Modified pyrolytic carbon black/natural rubber composites prepared by a wet compounding (WC) and latex mixing process have become an innovative technology route for waste tyre remanufacturing. The main properties and applications of CBp reported in recent years are reviewed, and the main difficulties affecting its participation in tyre recycling are pointed out. The research progress of using WC technology to replace dry mixing manufacturing of new tyres is summarized. Through literature data and comparative studies, this paper points out that the characteristic of high ash content can be well utilized if CBp is applied to tyre manufacturing. This mini-review proposes a new method for high-value utilization of CBp. The composite mixing of CBp and carbon nano-materials under wet conditions is conducive to the realization of their good dispersion in the rubber matrix. This provides a new idea for customer resource integration and connection of industry development between the tyre production industry and waste tyre disposal management.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 616
Author(s):  
Ján Kruželák ◽  
Andrea Kvasničáková ◽  
Klaudia Hložeková ◽  
Rastislav Dosoudil ◽  
Marek Gořalík ◽  
...  

In the present work, composite materials were prepared by incorporation of manganese-zinc ferrite, carbon black and combination of ferrite and carbon black into acrylonitrile-butadiene rubber (NBR). For cross-linking of composites, standard sulfur-based curing system was applied. The main goal was to investigate the influence of the fillers on the physical-mechanical properties of composites. Then, the electromagnetic absorption shielding ability was investigated in the frequency range 1 MHz–3 GHz. The results revealed that composites filled with ferrite provide sufficient absorption shielding performance in the tested frequency range. On the other hand, ferrite behaves as an inactive filler and deteriorates the physical-mechanical characteristics of composites. Carbon black reinforces the rubber matrix and contributes to the improvement of physical-mechanical properties. However, composites filled with carbon black are not able to absorb electromagnetic radiation in the given frequency range. Finally, the combination of carbon black and ferrite resulted in the modification of both physical-mechanical characteristics and absorption shielding ability of hybrid composites.


2012 ◽  
Vol 19 (01) ◽  
pp. 1250003
Author(s):  
JIAN CHEN ◽  
YONGZHONG JIN ◽  
JINGYU ZHANG ◽  
YAFENG WU ◽  
CHUNCAI MENG

Bound rubber in carbon black (CB) filled rubber (natural rubber (NR) and styrene–butadiene rubber (SBS)) was prepared by the solvent method. The nanomorphology of CB and rubber/CB soluble rubber was observed by atomic force microscope. The results show that high-structure CB DZ13 has a "grape cluster" structure which consists of many original particles with the grain size of about 30–50 nm. Graphitizing process of CB decreases the amount of bound rubber. The NR/DZ13 soluble rubber with island–rim structure has been obtained, where the islands are DZ13 particles and the rims around the islands are occupied by NR film. But when the graphitized DZ13 particles were used as fillers of rubber, we have only observed that some graphitized DZ13 particles were deposited on the surface of the globular-like NR molecular chains, instead of the spreading of NR molecular chains along the surface of DZ13 particles, indicating that graphitized DZ13 has lower chemical activity than ungraphitized DZ13. Especially, we have already observed an interesting unusual bound rubber phenomenon, the blocked "bracelet" structure with the diameter of about 600 nm in which CB particles were blocked in ring-shaped SBS monomer.


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