Immobilization of Elastomers at the Carbon Black Particle Surface

1970 ◽  
Vol 43 (5) ◽  
pp. 973-980 ◽  
Author(s):  
A. K. Sircar ◽  
A. Voet
Keyword(s):  
Carbon Black ◽  
Particle Surface ◽  
Carbon Black Particle ◽  
High Energy ◽  
Molecular Weights ◽  
Boiling Points ◽  
Furnace Black ◽  
Bound Rubber ◽  
Black Surface ◽  
Black Particle

Abstract Determinations have been made of the amount of elastomer unextractable from unvulcanized masticated mixes with carbon black by a given solvent at boil, expressed as immobilized elastomer. Saturated and unsaturated elastomers varying in molecular weights from 2000 to 325,000, were used, while solvents of greatly differing boiling points and solvent power were employed. It could be shown that the bonding between elastomers and carbon black is not a simple adsorption, but involves a higher energy interaction, defined as chemisorption. At successively higher temperatures elastomer is increasingly removed from the carbon black surface. The temperature Tm, obtained by extrapolation of the linear relationship between amounts immobilized and temperature of extraction, represents the temperature theoretically required to eliminate all bonds between carbon black and elastomer and is therefore indicative of the bond strength. Data suggest the existence of a bonding energy spectrum. Upon graphitization, blacks show a considerable decline in high energy bonding ability for elastomers. Saturated elastomers show less bonding than unsaturated elastomers with the same furnace black. “Bound rubber” represents the sum total of physically adsorbed, mechanically entangled, and chemisorbed elastomer. The actual values are greatly dependent upon the procedure used. “Immobilized rubber”, indicating chemisorbed elastomer, is easily determined, is not influenced by the method, and is more significant as an indicator of reinforcement.

Accessibility of the Carbon Black Particle Surface to Elastomers

1970 ◽  
Vol 43 (2) ◽  
pp. 464-469 ◽  
Author(s):  
P. Aboytes ◽  
A. Voet
Keyword(s):  
Carbon Black ◽  
Particle Surface ◽  
Carbon Black Particle ◽  
Carbon Chain ◽  
Chain Structure ◽  
Inert Atmosphere ◽  
Chemical Surface ◽  
Molecular Weights ◽  
Surface Areas ◽  
Black Surface

Abstract Experimental carbon blacks were prepared with the generally encountered slit-shaped pores of discrete dimensions of 9,12.5, and 16 A˚ width in greatly differing size distribution. Equilibrium adsorption in the saturation range was determined in n-hexane for butadiene—styrene elastomers of the SBR type of average molecular weights of 1500; 2000; 15,000; and 300,000. In attempting to correlate the saturation adsorption values with carbon black surface areas, it was found that a simple linear relation in the range investigated could only be obtained by assuming that pores of 9 A˚ width were inaccessible to SBR of 1500 and 2000 MW; that pores of 9 and 12.5 A˚ width were inaccessible to SBR of 15,000 MW; and that all pores smaller than 20 A˚ width were inaccessible to SBR of 300,000 MW. The data indicated that there are no differences between high, regular and low structure blacks in saturation elastomer adsorption under conditions of equivalent dispersion. Equally, upon breaking the persistent carbon chain structure by dry ball milling in an inert atmosphere and equalizing the chemical surface properties by removal of surface oxides, no difference in elastomer adsorption from solution was observed. It must be concluded that commonly used high molecular elastomers do not have any access to smaller carbon black pores. Since access to the surface is a prerequisite for reinforcement, it is obvious that the surface in the pores of carbon black generally does not participate in reinforcing elastomers. The elastomer adsorbed per unit external black surface area appears to be independent of the carbon chain structure, indicating that the so called surface activity of the carbon black is independent of the chain length.

scholarly journals Studies of Texaco Carbon Black Particle Surface by Polarography

1963 ◽  
Vol 84 (3) ◽  
pp. 212-214,A16 ◽  
Author(s):  
Shiro TAKASHIMA ◽  
Genzo HASHIZUME ◽  
Itaru MOTOOKA
Keyword(s):  
Carbon Black ◽  
Particle Surface ◽  
Carbon Black Particle ◽  
Black Particle

Determination of Carbon Black Particle Size by Reflectance

1967 ◽  
Vol 40 (5) ◽  
pp. 1319-1322 ◽  
Author(s):  
Merton L. Studebaker ◽  
Lester G. Nabors
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Sample Preparation ◽  
Simple Technique ◽  
Carbon Black Particle ◽  
Carbon Black Surface ◽  
Reflectance Meter ◽  
Black Surface ◽  
Black Particle

Abstract A simple technique of sample preparation using dry carbon black samples has been developed which gives a carbon black surface of reasonably reproducible reflectance, using a commercially available and reasonably priced reflectance meter. The reflectance values were calibrated against particle size determined by Kraus and Rollmann using the calorimetric procedure of Harkins and Jura.

Research on Electrical Double Percolation of Carbon Black-Filled Cement-Based Composites

2011 ◽  
Vol 311-313 ◽  
pp. 201-204
Author(s):  
Hong Zhong Ru ◽  
Ran Ran Zhao
Keyword(s):  
Carbon Black ◽  
Cement Paste ◽  
Volume Fraction ◽  
Carbon Black Particle ◽  
Carbon Black Content ◽  
Percolation Behavior ◽  
Key Factor ◽  
Binder Ratio ◽  
Black Particle ◽  
Double Percolation

Electrical conductive carbon black-filled cement-based composites are significant as multifunctional structural materials. Double percolation in carbon black-filled cement-based composites involves both carbon black particle percolation and cement paste percolation, which has great effect on the resistivity of composites. Based on double percolation theory, the influences of sand-binder ratio and carbon black volume fraction on the resistivity of carbon black-filled cement-based composites are investigated. The results show that besides carbon black volume fraction, sand-binder ratio is a key factor affecting double percolation behavior in carbon black-filled cement-based composites. At a fixed carbon black content in overall mortar, with increasing sand-binder ratio, the cement paste percolation though aggregate phase increases due to high obstruction of aggregate but the carbon black particle percolation in cement paste decreases. This is because that the microstructure of aggregate is impenetrable so that the carbon black particles are limited in cement paste, that is, the carbon black content in paste is compacted and large amount of conductive paths are generated by lapped adjacent carbon black particles in paste. The double percolation in the electrical conduction in carbon black-filled cement-based composites is observed when the carbon black volume fraction is 7.5% and sand-binder ratio is 1.4, and its resistivity is only 3200 Ωcm, so that a sand-binder ratio of 1.4 and 7.5% carbon black volume fraction or more are recommended for attaining high conductivity with a compromise between workability and conductivity.

Sorption of GR-S Type of Polymer on Carbon Black. III. Sorption by Commercial Blacks

1953 ◽  
Vol 26 (1) ◽  
pp. 102-114 ◽  
Author(s):  
I. M. Kolthoff ◽  
R. G. Gutmacher
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Intrinsic Viscosity ◽  
Benzene Solution ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Molecular Weights ◽  
Bound Rubber ◽  
Flow Through ◽  
Peculiar Behavior

Abstract The sorption capacities toward GR-S five commercial carbon blacks are in decreasing order: Spheron-6, Vulcan-1, Philblack-0, Sterling-105, Philblack-A. Apparently, the sorption is not related to surface area. The sorption on Vulcan-1 of GR-S from its solutions in seven different solvents or mixtures of solvents increases with decreasing solvent power for the rubber. The sorption curves of two “cold rubbers,” polymerized at −10 and +5° respectively, showed little difference from that of 50° GR-S. Previous heating of carbon black in nitrogen at 500 or 1100° increased the sorption by about 20 per cent over unheated carbon. Air-heating of carbon black at 425° did not cause a difference in the sorption from benzene solution, but produced an increase in the sorption of rubber from n-heptane solution. In the range 75% butadiene-25% styrene to 5% butadiene-95% styrene, there is practically no effect of the degree of unsaturation on the sorption. Polystyrene of high intrinsic viscosity exhibits a peculiar behavior with furnace blacks. Vulcan-1 sorbed microgel as well as the sol fraction from n-heptane solutions of GR-S containing microgel (conversion 74.7 and 81.5 per cent). There was no appreciable difference in the amount of sorption of rubber fractions having average molecular weights varying from 433,000 to 85,000. There is little change in the amount sorbed after two hours of shaking, but the intrinsic viscosity of the residual rubber decreases with time. The low molecular-weight rubber is sorbed more rapidly, but is slowly replaced by the more tightly sorbed high molecular weight fraction. Partial fractionation of a rubber sample can be achieved by allowing the rubber solution to flow through a column of weakly sorbing carbon black. A large portion of the sorbed rubber can be recovered from the column by washing it with a good solvent such as xylene. Bound rubber is produced by intimate mixing of equal parts of carbon black and rubber swollen in chloroform, when the mixture is dried in vacuum at 80° or at room temperature. Milling is not essential to get bound rubber.

PHYSICAL ADSORPTION STUDIES IN CARBON BLACK TECHNOLOGY

1955 ◽  
Vol 33 (2) ◽  
pp. 314-319 ◽  
Author(s):  
M. H. Polley ◽  
W. D. Schaeffer ◽  
W. R. Smith
Keyword(s):  
Carbon Black ◽  
Adsorption Isotherms ◽  
Unit Area ◽  
Physical Adsorption ◽  
Butyl Rubber ◽  
Chemisorbed Oxygen ◽  
Heat Treated ◽  
Furnace Black ◽  
Cyclic Heat ◽  
Black Surface

The adsorption isotherms of n-butane and butene-1 on typical furnace and channel carbon blacks were determined over a range of temperatures, 55°–250 °C. The adsorption of n-butane on carbon black surfaces is attributed to physical adsorption; however, the extent of surface covered per unit area of carbon black is considerably greater at a given temperature than for a silica. Butene-1 is also physically adsorbed on the furnace blacks. The presence of approximately 3% chemisorbed oxygen on the surface of the channel blacks induces an isomerization of butene-1 to cis-butene-2. When oxygen is first chemisorbed on a furnace black surface, then that surface also interacts with butene-1. Those blacks which participate in the isomerization of butene-1 respond or "interact" in a cyclic heat treated Butyl rubber – carbon black masterbatch.

Adsorption and Calorimetric Investigations on Carbon Black Surfaces. III. Immersion Heats in Model Elastomers and Isosteric Heats of Adsorption of C-4 Hydrocarbons

1972 ◽  
Vol 45 (1) ◽  
pp. 117-128 ◽  
Author(s):  
W. H. Wade ◽  
M. L. Deviney ◽  
W. A. Brown ◽  
M. H. Hnoosh ◽  
D. R. Wallace
Keyword(s):  
Carbon Black ◽  
Physical Adsorption ◽  
High Viscosity ◽  
High Energy ◽  
Heat Evolution ◽  
Carbon Substrate ◽  
Heats Of Adsorption ◽  
Adsorption Sites ◽  
Heat Of Wetting ◽  
Black Surface

Abstract The heats of immersion of U-1 channel and SAF, SPF, HAF-HS, and HAF furnace blacks have been measured at 25° C in three isoprenoid olefins and four liquid elastomers of the polybutadiene, polyisoprene, and SBR types. An extensive microcalorimeter redesign was necessary because of the high viscosity of these latter fluids. The immersion heats observed with the liquid elastomers were similar to n-decane immersion heats and there was little evidence for specific interactions between these liquids and any of the blacks. The possibility that the very high structure SPF black gives slightly enhanced immersion heats should be further investigated. Since only integral immersion heats could be measured with the non-volatile liquid elastomers, the possibility is not ruled out that specific, relatively high-energy interactions may occur between the adsorbate and a very small fraction of the black surface. The similarities between the immersion heats with n-decane and the liquid elastomers indicate that almost all of the carbon black surface is accessible to the polymer segments. It appears that the rate of heat evolution may be considered a measure of the rate of attainment of intimate molecular contact between the liquid and carbon substrate. The enhancement in heat of wetting with increasing chain length over the C6 to C16 n-alkane series reported by others with a highly uniform, graphitized black was not observed with HAF. Isosteric heats of adsorption of n-butane and butene-1 at low surface coverages on several carbon blacks were calculated from adsorption isotherms obtained with a precision microgravimetric system. The isosteric heats as a function of coverage curves were typical of those expected for heterogeneous surfaces and reflected the presence of high energy physical adsorption sites at low coverages (θ<0.1).

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