The Effect of Carbon Black on Thermal Antioxidants for Polyethylene

1959 ◽  
Vol 32 (4) ◽  
pp. 1164-1170 ◽  
Author(s):  
W. L. Hawkins ◽  
R. H. Hansen ◽  
W. Matreyek ◽  
F. H. Winslow
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Chemical Nature ◽  
Antioxidant Effect ◽  
Carbon Surface ◽  
Carbon Blacks ◽  
Wide Ph Range ◽  
Black Surface ◽  
Phenol Antioxidants ◽  
Ph Range

Abstract Carbon black has been shown to function as a mild thermal antioxidant for polyethylene at 140° C. The amount of protection increases with concentration and is dependent on the chemical nature of the carbon surface. This antioxidant effect is shown by a variety of carbon blacks with a considerable range of particle size, but very coarse carbons in comparable weight concentration exhibit no antioxidant effect. Recent studies concerned with the chemical nature of the carbon black surface indicate the presence of various oxygenated groupings which may account for the weak antioxidant activity of some carbon blacks. In all cases examined, conventional amine and phenol antioxidants in polyethylene are adversely affected by carbon black. This effect can be attributed to adsorption followed by chemical decomposition of the antioxidant on the carbon black. The chemical nature of the carbon black apparently influences the adsorption since the loss in activity of amine antioxidants is much more pronounced with acidic than basic carbon blacks. Whereas the effect of carbon black on antioxidant behavior is observed over a wide pH range, the effect decreases and finally disappears as the particle size of the carbon black is increased.

Effect of Heat Treatment on Reinforcing Properties of Carbon Black

1956 ◽  
Vol 29 (1) ◽  
pp. 286-295
Author(s):  
W. D. Schaeffer ◽  
W. R. Smith
Keyword(s):  
Carbon Black ◽  
Volatile Matter ◽  
Graphitized Carbon Black ◽  
Carbon Surface ◽  
Minor Effect ◽  
Carbon Blacks ◽  
Carbon Black Surface ◽  
Black Surface ◽  
High Degree ◽  
Degree Of Graphitization

Abstract The high degree of stiffness or modulus which reinforcing carbon blacks impart to rubber has often been associated with reinforcement. Modulus appears to be associated with the chemical nature of the carbon black surface ; when the carbon black surface is cleaned of combined oxygen and hydrogen, a drastic drop in modulus occurs, and this is not accompanied by an equally drastic decrease in tire road wear. Reinforcing and semireinforcing carbon blacks have been heat-treated at successive increments through a temperature range of 1000° to 2700° C. Treatment up to 1500° results in removal of all combined oxygen and hydrogen, followed by an increasing degree of graphitization at higher temperatures. These carbon blacks have been compounded in a standard natural-rubber compound and properties evaluated. Modulus is profoundly altered by the chemistry of the carbon surface. Electrical resistivity passes through a minimum at 1500° C. Scorchiness or premature vulcanization improves with removal of volatile matter. The degree of graphitization of the carbon has only a minor effect on rubber properties. A highly graphitized carbon black still imparts a high degree of resistance to abrasive wear to tire treads.

New Thermal Antioxidants for Polyethylene Containing Carbon Black

1959 ◽  
Vol 32 (4) ◽  
pp. 1171-1179 ◽  
Author(s):  
W. L. Hawkins ◽  
V. L. Lanza ◽  
B. B. Loeffler ◽  
W. Matreyek ◽  
F. H. Winslow
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Carbon Black ◽  
General Class ◽  
Chemical Nature ◽  
Significant Degree ◽  
Active Hydrogen ◽  
Considerable Evidence ◽  
Carbon Black Surface ◽  
Black Surface

Abstract Antioxidants which contain a thioether bond are usually more effective than the simple compounds from which they are derived. More significant is the effect of carbon black on these improved antioxidants, generally resulting in even greater protection than in the clear polymer. This is in contrast to the behavior of conventional antioxidants which do not contain a thio-bond. In all cases examined, these conventional antioxidants lose a large proportion of their effectiveness in the presence of carbon black. Recent studies concerned with the chemical nature of the carbon black surface strongly suggest the presence of reactive chemical groupings which may account for the weak antioxidant activity of some carbon blacks. Apparently the carbon black surface interacts with organo-sulfur antioxidants since this unique behavior has not been observed in other materials of comparable particle size, such as alumina, titania, or silica, nor do these materials themselves inhibit polyethylene oxidation. Thioethers and disulfides which contain no amine or phenol groups and hence no active hydrogen constitute another class of antioxidants which are unusual in that they attain a significant degree of activity only in the presence of carbon black. Although the mechanism through which these simple compounds function as antioxidants has not been established, there is considerable evidence that a relationship exists between antioxidant activity and bond dissociation energy. Some thiols may act to a slight extent as conventional antioxidants in clear polyethylene, but when carbon black is present, they appear to function through the same mechanism as do the simple organo-sulfur compounds which contain no active hydrogen. It is significant that within the general class of organo-sulfur antioxidants, alkyl compounds exhibit strong antioxidant activity in the presence of carbon black, and are often comparable with their aromatic counterparts.

Radiotracer Studies of Carbon Black Surface Interactions with Organic Systems. I. Experimental Approach and Initial Results from Chemisorption and Vinyl Polymerization Studies

1968 ◽  
Vol 41 (2) ◽  
pp. 382-399 ◽  
Author(s):  
Marvin L. Deviney ◽  
Lawrence E. Whittington
Keyword(s):  
Carbon Black ◽  
Functional Groups ◽  
Reaction Mechanisms ◽  
Hydrogen Abstraction ◽  
Surface Interactions ◽  
Carbon Surface ◽  
Organic Systems ◽  
Carbon Black Surface ◽  
Basic Reaction ◽  
Black Surface

Abstract Radiotracer techniques have been applied to the study of interactions of carbon black surface functional groups with two chosen organic systems. The basic reaction mechanisms demonstrated in this study may have implications in elastomer reinforcement. Direct radiochemical evidence supports the conclusions of Hallum and Drushel (based on less direct polarographic data) that surface quinonic groups exhibit hydrogen abstraction activity toward tertiary hydrogens in paraffinic hydrocarbons. Studies on the system carbon black and styrene using tritium radiotracer have provided direct evidence that phenolic hydrogens participate in the polymerization acceleration and graft polymer formation reaction and are transferred to the growing polystyrene chains as postulated by Donnet. Several methods have been developed for specifically labelling certain oxygenated functional groups on the carbon surface with tritium and for tritium labelling carbon black in aromatic hydrogen positions. The techniques developed in this work and the basic reaction mechanisms derived will permit this investigation to be extended into a radiochemical study of carbon black surface interactions with elastomer related systems of interest to the rubber industry.

INVESTIGATION OF THE ELECTROCHEMICAL BEHAVIOR OF HEAT-TREATED CARBON BLACKS AND Pt/C CATALYSTS

2002 ◽  
Vol 09 (03n04) ◽  
pp. 1443-1452 ◽  
Author(s):  
C. D. HUANG ◽  
Z. T. XIONG ◽  
J. Y. LIN ◽  
K. L. TAN
Keyword(s):  
Carbon Black ◽  
Electrochemical Behavior ◽  
Catalyst Support ◽  
Carbon Surface ◽  
Carbon Blacks ◽  
Heat Treated ◽  
Platinum Particles ◽  
Electro Oxidation ◽  
Treated Carbon ◽  
Xps Study

In this paper we report the electrochemical behavior of heat-treated carbon blacks and Pt/C catalysts. Cyclic voltammetry indicates that the heat-treated carbon black as catalyst support does not improve the Pt/C catalyst's activity for methanol oxidation. An XPS study of a Pt-loaded carbon black indicates that the amounts of oxidized platinum and oxygen-functional groups on catalysts are decreased when the platinum particles are deposited on the heat-treated carbon surface. These changes in the surface and crystalline structural properties of carbon materials lead to the catalytic activity change in methanol electro-oxidation.

An NMR Investigation of the Interaction between Carbon Black and Cis-Polyisoprene

1980 ◽  
Vol 53 (4) ◽  
pp. 975-981 ◽  
Author(s):  
L. G. Svensson ◽  
S. E. Svanson
Keyword(s):  
Carbon Black ◽  
Main Part ◽  
Chemical Nature ◽  
Physical Nature ◽  
Surface Interaction ◽  
Carbon Blacks ◽  
Irreversible Effects

Abstract Attempts have been made to change the methods of preparation of samples of IR filled with various carbon blacks. Considering experiments where reliable results have been obtained hitherto we have drawn the following conclusions: 1. For solution-mixed and short-milled samples, a large broadening is observed, which is reduced by extraction, heating the samples above 50°C, and by prolonged milling. It is assumed that this broadening is due to interactions of a physical nature. The remaining broadening effect is assigned to irreversible effects of a chemical nature. 2. For dry-milled samples, where prolonged milling is always needed to achieve reasonable mixing, the main part of the broadening effects is not changed by the above treatments. 3. By heating the products to temperatures above 180°C a pronounced broadening develops. We believe that the largest surface interaction is attained by this treatment.

THE ADSORPTION OF SODIUM MYRISTATE BY CARBON BLACK

1949 ◽  
Vol 27f (11) ◽  
pp. 426-428 ◽  
Author(s):  
Marguerite A. Reade ◽  
A. S. Weatherburn ◽  
C. H. Bayley
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Fatty Acid ◽  
Carbon Black ◽  
Surface Area ◽  
Activated Charcoal ◽  
Carbon Blacks ◽  
Preferential Adsorption

The adsorption of sodium myristate from 0.1% aqueous solution by a series of carbon blacks and an activated charcoal has been measured at 70 °C. In every case a preferential adsorption of fatty acid was observed. The extent of adsorption of both the fatty acid and alkali components of the soap increased with decreasing particle size, i.e., with increasing surface area, of the carbons. The adsorption by activated charcoal was considerably higher than that obtained with even the finest of the carbon blacks.

Reactions of Polymers in Bulk. I. Influence of Fillers on the Degree of Crosslinking of Natural Rubber

1962 ◽  
Vol 35 (3) ◽  
pp. 563-571 ◽  
Author(s):  
J. Janacek
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Specific Surface ◽  
Contact Surface ◽  
Chemical Nature ◽  
Chain Structure ◽  
Filler Concentration ◽  
Carbon Blacks

Abstract The relation between the degree of crosslinking determined by means of swelling and the theoretical total contact surface of rubber to carbon black was investigated with vulcanizates of two elastomers which were cured by various vulcanization methods and using various concentrations—even extremely high ones—of carbon blacks with different specific surface, degrees of chain structure and chemical activities. A constant, α, the magnitude of which generally depends upon the degree of agglomeration of the carbon blacks and on the chemical nature of their surface as well as on the polymers used and the vulcanization method, but which is practically unrelated to the filler concentration, has been proposed to express the relative crosslinking activity of carbon blacks.

Carbon Black Surface Areas by the Harkins and Jura Absolute Method

1967 ◽  
Vol 40 (5) ◽  
pp. 1305-1310 ◽  
Author(s):  
G. Kraus ◽  
K. W. Rollmann
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Surface Area ◽  
Nitrogen Adsorption ◽  
Absolute Method ◽  
Carbon Blacks ◽  
Surface Areas ◽  
Particle Size Determination ◽  
Light Reflectance ◽  
Adsorption Surface

Abstract The Harkins and Jura (HJ) absolute method of surface area determination (Harkins and Jura, J. Am. Chem. Soc. 66, 919, 1944) has been applied to a large number of carbon blacks. Surface area is calculated from the heat of immersion of the solid powder covered by a preadsorbed multilayer of the immersion liquid. For non-porous carbon blacks good agreement with nitrogen adsorption surface areas is obtained, but with porous blacks the HJ method gives smaller values since micropores are filled and bridged over by the pre-adsorbed film. Thus the HJ areas are more nearly representative of particle size and may be used to calibrate indirect methods of particle size determination. An example of this is shown using light reflectance values on dry carbon black and possible complications due to particle size distribution in the use of the reflectance test are discussed.

Influence of Carbon Black on the Oxidation of Natural Rubber

1953 ◽  
Vol 26 (4) ◽  
pp. 862-868
Author(s):  
G. J. van Amerongen
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Natural Rubber ◽  
Oxidation Reaction ◽  
Catalytic Action ◽  
Particle Sizes ◽  
Carbon Blacks ◽  
Aging Resistance ◽  
Solubility Of Oxygen

Abstract In this investigation an attempt was made to determine to what extent the solubility of oxygen in natural rubber and the aging resistance are influenced by the incorporation of carbon blacks of various particle sizes in the rubber. The influence of the particle size of carbon black on the oxidizability of GR-S loaded with carbon black had already been proved by Winn, Shelton, and Turnbull. In their explanation of this effect, carbon black was considered to be a catalyst for the oxidation reaction of rubber, although nothing was known about the nature of this catalytic action. Moreover, measurements with natural rubber were lacking.

Sign in / Sign up

Export Citation Format

Share Document