Characterization of New Technology Carbon Blacks

1973 ◽  
Vol 46 (5) ◽  
pp. 1239-1255 ◽  
Author(s):  
A. I. Medalia ◽  
E. M. Dannenberg ◽  
F. A. Heckman ◽  
G. R. Cotten
Keyword(s):  
Carbon Black ◽  
Iodine Number ◽  
Surface Activity ◽  
New Technology ◽  
Aggregate Size ◽  
Nitrogen Adsorption ◽  
Solid Sphere ◽  
Sphere Diameter ◽  
Bound Rubber ◽  
Morphological Differences

Abstract In this paper we have examined a limited number of conventional and new technology blacks, using the “t” method of nitrogen adsorption for comparison of surface area and dibutyl phthalate adsorption (DBPA) for comparison of structure. At a given “t” area the new technology blacks are of lower iodine number; conversely, at a given iodine number, the new technology blacks are of higher “t” area. This is not due to porosity, but rather to differences in carbon black-iodine surface interaction. The DBPA tests gives a fairly consistent measure of carbon black structure in rubber, for both types of blacks. An important difference between the two classes of black is in the higher tinting strength of new technology blacks, at a given “solid sphere” diameter (which depends primarily on the “t” area and to a lesser extent on the DBPA). We have introduced the use of a disk photosedimentometer for studying carbon black aggregate size distributions and have found that at a given “t” area, the distribution curves for the new technology blacks are shifted in the direction of smaller Stokes diameters. This can account, at least qualitatively, for their higher tinting strength. Electron microscopy supports the shift in Stokes diameters, at least qualitatively, and also indicates a more open aggregate morphology for the new technology blacks. The new technology blacks impart a higher level of reinforcement, at the same “t” area, as shown by tensile strength and roadwear. This is accompanied by a higher loss tangent or lower rebound. These properties may be due in part to a higher surface activity, as shown by a higher moisture adsorption and higher bound rubber, and partly to morphological differences, as shown by the smaller Stokes diameters and higher tinting strength. In summary, the higher bound rubber and higher tinting strength of the new technology blacks reflect differences in surface activity and aggregate size, which are responsible for the superior reinforcement shown by these blacks at a given “t” area.

The Effect of Structure Breakdown of Carbon Black on Rubber Properties

1974 ◽  
Vol 47 (5) ◽  
pp. 1082-1093 ◽  
Author(s):  
B. B. Boonstra ◽  
E. M. Dannenberg ◽  
F. A. Heckman
Keyword(s):  
Carbon Black ◽  
New Technology ◽  
Aggregate Size ◽  
Void Volume ◽  
Diameter Distribution ◽  
Sphere Diameter ◽  
Projected Image ◽  
Carbon Blacks ◽  
Normal Carbon ◽  
First Time

Abstract Mechanical processing of carbon blacks by a novel pressure-milling technique provides a controlled breakdown of primary carbon-black aggregates. In contrast, direct compression has a much smaller effect on aggregate size. In rubber vulcanizates, the pressure-milled carbon blacks give about the same vulcanizate properties as normal carbon blacks with the same void volume or DBP absorption value. Breakdown of aggregates occurs during the process of incorporating and dispersing carbon black in rubber. The retention of average aggregate size after mixing in rubber is in the range of 60–70 per cent for Vulcan M (N339), a new technology tread black. We have shown that the DBP absorption method cannot distinguish between loss in void volume by compaction of aggregates versus the actual breakdown of aggregates. The sedimentation method by centrifuging provides a means for measuring aggregate size independent of the original packing of the dry black. In order to carry out these studies, a number of new experimental techniques were used. These include: a) controlled aggregate size breakdown by pressure-milling. b) Stokes diameter distribution measurements by centrifuging aqueous dispersions in a Joyce Loebl apparatus. c) Quantimet analysis of projected aggregate areas from electron micrographs from specially prepared solvent dispersions of rubber-carbon black samples where the aggregates are clear of interference from adhering rubber. It has been shown for the first time that for both Vulcan M (N339) and Vulcan 6 (N220) the median Stokes diameters, DSt, obtained by the centrifuge method and the equivalent sphere diameter, De, from Quantimet projected image analysis are in the range of 123–153.

Dynamic Testing and Reinforcement of Rubber

1988 ◽  
Vol 61 (5) ◽  
pp. 842-865 ◽  
Author(s):  
J. M. Funt
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Hydrodynamic Interaction ◽  
Dynamic Testing ◽  
Large Strain ◽  
Aggregate Size ◽  
Effective Volume ◽  
Bound Rubber ◽  
Rubber Forming ◽  
Entanglement Network

Abstract A series of experiments have been run to determine which mechanisms dominate carbon black reinforcement of rubber. A broad range of compounds using oil-extended and non-oil-extended rubbers and carbon blacks covering the spectrum of tread blacks have been tested. The results for measurements made in an all-SBR formulation are reported here. The primary experiment consisted of measurement of the dynamic modulus and hysteresis of the cured and uncured compounds over a broad range of frequencies, temperatures, and strains. Ternperatures ranged from −70°C to +90°C; frequencies varied from 0.01 to 10 Hz; double strain amplitudes varied from 0.5% to 35%. From a discussion of the literature and evaluation of the experimental results, two mechanisms have been found to control the primary effects of carbon black on rubber reinforcement, where reinforcement refers to a general enhancement of properties, such as modulus, as well as the tensile strength of the compound. Hydrodynamic interaction, which is the increase in properties caused by the modification of strain fields in the region of an aggregate, dominates the large-strain dynamic and tensile properties of the compound. The primary carbon black variable in this mechanism is the effective aggregate size, such as measured by tint, which controls the effective volume loading of the carbon black at a given weight loading of carbon black. At low strains, the modulus is even higher than that predicted from the hydrodynamic-interaction/effective-volume model. This additional reinforcement is caused by the entanglement network formed between the tightly absorbed bound rubber on the carbon black surface and the bulk rubber far removed from the surface. The main carbon black variables in this mechanism are surface area and surface chemistry. The strain dependence of modulus is caused by the breaking and reforming of effective crosslinks in the rubber forming a transition zone between the bound rubber and the bulk rubber. To a large extent, this mechanism is dominated by the rubber properties, such as molecular weight and molecular-weight distribution. However, the dynamics of the entanglement network may be modified by altering specific interactions between carbon black and rubber.

Carbon-Black-Elastomer Interaction

1991 ◽  
Vol 64 (1) ◽  
pp. 19-39 ◽  
Author(s):  
J. A. Ayala ◽  
W. M. Hess ◽  
F. D. Kistler ◽  
G. A. Joyce
Keyword(s):  
Carbon Black ◽  
Surface Activity ◽  
Chemical Reactivity ◽  
Surface Reactivity ◽  
Moisture Adsorption ◽  
Carbon Blacks ◽  
Bound Rubber ◽  
Carbon Black Surface ◽  
Black Surface ◽  
Polymer Interaction

Abstract A number of different techniques were applied to measure carbon-black-surface reactivity and the level of black-polymer interaction in four different elastomer systems (SBR, IIR, NR, and NBR) representing differences in unsaturation, crystallinity and polarity. Known within-grade surface activity variations were based on partial graphitization of an N121-type carbon black. The surface activity of different black grades was studied as a function of variations in both surface area and DBPA. Direct measurements of carbon-black-surface reactivity were based on hydrogen analysis, SIMS, IGC, and moisture adsorption. In-rubber measurements included bound rubber, SIMS of cut surfaces, and an interaction parameter, σ/η, which is derived from the slope (σ) of the stress-strain curve at low elongations, and (η), the ratio of dynamic modulus (E′) at 1% and 25% DSA. The following trends were observed: 1. The σ/η values provided a good measure of black-polymer interaction in all four polymer systems for either the within-grade or across-grade comparisons. 2. Higher σ/η values were indicated for SBR and NBR, followed by NR and IIR in that order. 3. SBR indicated the greatest sensitivity for bound-rubber measurements in terms of distinguishing within-grade variations in black-polymer interaction, followed by IIR, NR, and NBR in that order. 4. Positive SIMS on dry carbon black indicates the presence of complex hydrocarbon structures suitable for chemical reactivity at the carbon-black surface. 5. SIMS analyses on the dry carbon blacks exhibited intensity variations in the negative hydrocarbon fragments which were in line with the within-grade variations in hydrogen content. 6. SIMS analyses on the cut-rubber compound surfaces showed overall variations in intensity which were proportional to the range and level of the bound-rubber measurements. The most meaningful variations were recorded for SBR and IIR. 7. Heats of adsorption derived from IGC measurements with different adsorbates showed an excellent correlation with black-polymer interaction for the within-grade studies. Measurements across grades did not correlate as well with the in-rubber measurements, but the best results were obtained using styrene as the adsorbate. 8. The within-grade moisture adsorption measurements showed excellent agreement with IGC and the other techniques for the N121 series of heat-treated carbon blacks.

Influence of Fillers Surface Characteristics on Bound Rubber Properties of Filled Natural Rubber Compounds

2013 ◽  
Vol 845 ◽  
pp. 412-416 ◽  
Author(s):  
Mustafa Kamal Mazlina
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Surface Activity ◽  
Specific Activity ◽  
Filler Particle ◽  
Surface Characteristics ◽  
Rubber Content ◽  
Rubber Compounds ◽  
Bound Rubber ◽  
Service Application

One of the most important phenomena in rubber science is the reinforcement by rigid entities, such as carbon black, clays, silicates and calcium carbonate. Thus, these fillers are added to rubber formulations to optimise properties that meet a given service application or set of performance parameters. Fillers can be divided into three categories reinforcing, semi-reinforcing and non-reinforcing. For a given elastomer and state of mix, bound rubber can be considered as a measurement of a surface activity of a filler and is considered as one of major factors in reinforcement. A strong rubber: filler interaction results in a large bound rubber content. Good dispersions and distribution of filler aggregates is also important for the full reinforcing potential of fillers to be reached. In this study, the influence of fillers on bound rubber content of Natural Rubber compounds were determined and compared. Results showed that the bound rubber content followed the trend of Carbon Black>Silica>Carbon Black>Starch. The two main filler characteristics that affect the bound rubber properties are the filler particle size and surface activity. The specific activity of the filler is determined by the physical and chemical nature of the filler surface in relation to that of elastomer. Keywords: reinforcement, surface energy

scholarly journals On factors affecting surface free energy of carbon black for reinforcing rubber

2020 ◽  
Vol 9 (1) ◽  
pp. 170-181 ◽  
Author(s):  
Shangyong Zhang ◽  
Ruipeng Zhong ◽  
Ruoyu Hong ◽  
David Hui
Keyword(s):  
Free Energy ◽  
Carbon Black ◽  
Surface Free Energy ◽  
Surface Activity ◽  
Gas Flow ◽  
Influential Factors ◽  
Chromatographic Column ◽  
Factors Affecting ◽  
Carrier Gas Flow

AbstractThe surface activity of carbon black (CB) is an important factor affecting the reinforcement of rubber. The quantitative determination of the surface activity (surface free energy) of CB is of great significance. A simplified formula is obtained to determine the free energy of CB surface through theoretical analysis and mathematical derivation. The surface free energy for four kinds of industrial CBs were measured by inverse gas chromatography, and the influential factors were studied. The results showed that the aging time of the chromatographic column plays an important role in accurate measurement of the surface free energy of CB, in comparison with the influences from the inlet pressure and carrier gas flow rate of the chromatographic column filled with CB. Several kinds of industrial CB were treated at high temperature, and the surface free energy of CB had a significant increase. With the increase of surface free energy, the maximum torque was decreased significantly, the elongation at break tended to increase, the heat generation of vulcanizates was increased, and the wear resistance was decreased.

Microstructure of Carbon Black

1964 ◽  
Vol 37 (5) ◽  
pp. 1245-1298 ◽  
Author(s):  
F. A. Heckman
Keyword(s):  
Carbon Black ◽  
Gas Adsorption ◽  
Current Knowledge ◽  
Aggregate Size ◽  
Surface Characteristics ◽  
The Body ◽  
Degree Of Crystallinity ◽  
Complete Treatment ◽  
Real Value ◽  
Forms Of Carbon

Abstract Although the microstructure of carbon black has been under investigation for more than fifty years, there are still many aspects which are controversial and some which are virtually unexplored. The inherently low degree of crystallinity and the finely-divided state of carbon blacks have greatly hindered efforts to understand them. The purpose of this article is to cite the principal contributors to our understanding of carbon black microstructure, to discuss the significance of their contribution, to present a clear picture of the present state of our knowledge, and to note areas where controversy exists and where our knowledge is incomplete. The scope of this article is necessarily limited to a reasonably complete treatment of the several aspects of carbon black microstructure; that is, the arrangement of carbon atoms to form graphite layer planes, the arrangement of layer planes to form crystallites, and the arrangement of crystallites to form the more familiar carbon black “particles” or aggregates. Particular attention is paid to more recent articles and those which have shaped our thinking on carbon black microstructure. This article also includes a fairly complete review of various studies on the changes in microstructure which are brought about by heat treatment or oxidation. In general, the rather large number of studies reporting on the microstructure of other forms of carbon have not been reviewed (except for the work of Franklin whose contribution to our understanding of carbon-black microstructure is so immense that it must be included). Although gross, morphological features such as particle size, primary aggregate size and shape are studied briefly in order to relate them to microstructure, no effort was made to review comprehensively the body of literature pertinent to this subject. Also porosity and surface characteristics per se (as measured by gas adsorption techniques) are not treated in detail here. Rather than review a dreary list of papers which have only the slightest bearing on carbon black, the author has taken the liberty of dividing the articles reviewed into two categories. The first category, which is reviewed in some detail, includes those publications in which an important contribution was made to the understanding of carbon-black microstructure. The second category includes all those articles which are discussed only briefly or not at all because the authors have reported superficial or routine studies or they (probably unknown to them) have essentially duplicated the work of an earlier worker, or have reported uncorrected results which are thus so inaccurate as to be without real value to this article; or because they comprise work which is only peripherally related to carbon black microstructure. Also, references taken from other papers, but not reviewed here, are included in the latter category. Articles by Warren, Hofmann and Wilm, Steward and Cook and Walker contain bibliographies which will be helpful to those interested in the earlier work or in the microstructure of carbons other than carbon black. For the reader whose time is limited, an adequate picture of current understanding of carbon black microstructure can be gained by reading Sections II, IV, and V which are relatively short. Finally, a word about the spirit in which the review was written. At the request of the late Dr. Craig, a critical review was prepared in which every effort was made to point out shortcomings as well as classic contributions contained in the pertinent literature. Where the experts have disagreed, the reviewer, often with skill unequal to the task, has attempted to decide which one was the more correct in the light of current knowledge. It is with deep humility and great respect for those who have gone before that this review is submitted.

STUDY ON NANOMORPHOLOGY OF HIGH-STRUCTURE CARBON BLACK AND ITS BOUND RUBBER BY AFM

2012 ◽  
Vol 19 (01) ◽  
pp. 1250003
Author(s):  
JIAN CHEN ◽  
YONGZHONG JIN ◽  
JINGYU ZHANG ◽  
YAFENG WU ◽  
CHUNCAI MENG
Keyword(s):  
Carbon Black ◽  
Cluster Structure ◽  
Chemical Activity ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Atomic Force ◽  
Filled Rubber ◽  
Bound Rubber ◽  
Styrene Butadiene ◽  
High Structure

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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