Evidence for Chemical Interaction in Carbon and Polymer Associations. Extension of Original Work on Effect of Carbon Black Structure

1969 ◽  
Vol 42 (3) ◽  
pp. 858-873 ◽  
Author(s):  
A. M. Gessler
Keyword(s):  
Free Radical ◽  
Carbon Black ◽  
Natural Rubber ◽  
Chemical Interaction ◽  
Ethylene Propylene ◽  
Bound Rubber ◽  
Close Relationship ◽  
Subsequent Behavior ◽  
High Structure ◽  
Free Radical Activity

Abstract Selected proposals regarding the mechanism of carbon and polymer interaction were reviewed from the literature. With this material as background, the bound rubber capacity of low and high structure HAF blacks was studied over a broad concentration range in four previously unstudied polymers: ethylene-propylene copolymer, chlorinated butyl, cis-1,4-polybutadiene, and natural rubber. Experimental evidence from the resulting work was combined with that from a similar previous study involving five polymers: polyisobutylene, butyl, two ethylene-propylene terpolymers differing in free radical activity, and SBR. With low structure black, the extent of bound rubber formation varies with the activity of the polymer functionality, in accordance with expectation. Previously proposed mechanisms for the bonding of rubber and black are used to resolve the differences which are shown. With high structure black, the primary carbon-to-polymer bonding effects referred to above are overshadowed by the formation, in situ, of a facile, new free radical source which is proposed to result from the mechanical breakage of aggregated carbon black structure during the milling of rubber and black. This imposed free radical activity is shown to have a profound effect on the subsequent behavior of the polymer. The inclusion of sulfur (2.0 php) in bound rubber systems leads to some extremely interesting results. Except for natural rubber, polymer is not crosslinked by the action of sulfur alone, even when the systems are heated as in vulcanization. The high bound rubber levels which are formed when sulfur and black are both present, especially with butyl, are proposed to result first from a reaction of sulfur with the black, and second, from reaction of this sulfur-modified black with the polymer. The close relationship between vulcanization and reinforcement is thus attested.

Chemical Interaction between Surface Oxidized Carbon Black and Epoxidized Natural Rubber

1997 ◽  
Vol 70 (4) ◽  
pp. 624-633 ◽  
Author(s):  
Ajoy K. Manna ◽  
P. P. De ◽  
D. K. Tripathy ◽  
S. K. De ◽  
M. K. Chatterjee
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Chemical Interaction ◽  
Epoxidized Natural Rubber ◽  
Spectral Studies ◽  
Enthalpy Of Reaction ◽  
Bound Rubber ◽  
Infrared Spectral ◽  
Oxidized Carbon ◽  
Swelling Studies

Abstract This study—based on Monsanto Rheometer measurements, determination of bound rubber, enthalpy of reaction, solvent swelling studies, and measurement of physical properties— revealed that the functional groups of intermediate super abrasion furnace (ISAF) carbon black chemically interact with the epoxidized natural rubber. The extent of interaction is greater in the case of an oxidized grade of ISAF black than the nonoxidized grade. Infrared spectral studies show that the interaction between the rubber and carbon black leads to chemical bond formation. It is believed that the oxidized grade of carbon black forms ester-type as well as phenolic ether-type bonds, while the nonoxidized grade forms primarily the phenolic ether-type of linkages.

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.

Bound—Rubber Formation in Diene Polymer Stocks

1958 ◽  
Vol 31 (2) ◽  
pp. 369-373 ◽  
Author(s):  
P. B. Stickney ◽  
E. E. McSweeney ◽  
W. J. Mueller ◽  
S. T. Palinchak
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Recent Work ◽  
Experimental Approach ◽  
Polymer Gel ◽  
Fine Powders ◽  
Bound Rubber ◽  
Close Relationship ◽  
Static Extraction ◽  
Rubber Filler

Abstract The phenomenon of insolubilization of rubber by carbon black has been known for at least twenty-seven years. There have been many attempts during this time to establish a relationship between insolubilization, or bound rubber formation, and reinforcement of rubber by carbon black. It was postulated, as far back as 1925, that there was a parallelism between particle size and insolubilization. This in spite of the fact that the methods available for determining particle size of very fine powders at that time were relatively crude. It was postulated at that time that there was a close relationship between the phenomena of vulcanization and reinforcement. This concept has had recurrent periods of popularity since that time. The insolubilization of rubber by carbon black, or other pigments, has been estimated by various techniques by the early investigators in the field. In more recent work, the trend has been toward a very straightforward experimental approach. Bound rubber in an uncured rubber-filler compound is usually determined by static extraction using the same apparatus and techniques used in determining the gel content of unfilled polymers. It follows that, using this method, polymer insoluble because of crosslinking, or gel, cannot be distinguished from polymer insolubilized by incorporation of fine fillers. In investigating the formation of bound rubber, therefore, the presence of gel in the polymer being used, or formation of polymer gel during processing must be taken into account.

Molecular Weight Effects in Adsorption of Rubbers on Carbon Black

1968 ◽  
Vol 41 (5) ◽  
pp. 1256-1270 ◽  
Author(s):  
Gerard Kraus ◽  
J. T. Gruver
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Large Particle ◽  
Molecular Weights ◽  
Molecular Weight Dependence ◽  
Bound Rubber ◽  
Sieve Effect ◽  
High Structure ◽  
Very High ◽  
Poor Solvent

Abstract The molecular weight dependence of the adsorption of polybutadiene on carbon black from a poor solvent, n-heptane, and bulk, i.e., the phenomenon of “bound rubber”, was investigated. For narrow distribution polymers the adsorption is proportional to Mn, where n = 0.14 for adsorption from n-heptane solution; n = 0.5 for adsorption from bulk. Anomalously low solution adsorption was observed for polymers of very high molecular weight (> 500,000). This is ascribed to a sieve effect by aggregates of carbon black particles which cannot be penetrated by the large molecular coils. In high structure blacks, which pack more loosely, and in large particle blacks, which form larger interstices between particles, onset of anomalous adsorption is shifted toward higher molecular weights.

Studies on MBT-Accelerated Sulfur Vulcanization of Natural Rubber Reinforced with Carbon Black

1974 ◽  
Vol 47 (2) ◽  
pp. 251-265 ◽  
Author(s):  
S. Bhoumick ◽  
S. Banerjee
Keyword(s):  
Free Radical ◽  
Carbon Black ◽  
Stearic Acid ◽  
Natural Rubber ◽  
Radical Mechanism ◽  
Free Radical Mechanism ◽  
Sulfur Vulcanization ◽  
Polar Mechanism

Abstract Studies have been made on the mechanism of MBT accelerated sulfur vulcanization of natural rubber containing semi-reinforcing carbon black as a filler. DCP has been used as an aid to distinguish between free radical and polar mechanism. Results indicate that sulfuration by MBT and sulfur proceed by a free radical mechanism but it becomes polar when ZnO and stearic acid are also present. Carbon black does not interfere in the sulfuration but it gives rise to additional crosslinks.

Effects of the Types of Rubber and Carbon Black on the Formation of Carbon-Rubber Gel

1959 ◽  
Vol 32 (4) ◽  
pp. 1185-1191
Author(s):  
Z. V. Chernykh ◽  
V. G. Epshtein
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Gel Formation ◽  
Active Carbons ◽  
Carbon Blacks ◽  
Bond Stability ◽  
Carbon Structures ◽  
Bound Rubber

Abstract 1. Carbon-rubber gels are formed in mixtures containing all the types of carbon black tested (channel, acetylene, nozzle, furnace, thermal) and not only active carbons. 2. The amount of carbon-rubber gel formed depends on the amount of carbon black added. With carbon blacks which readily form continuous carbon structures (channel, acetylene) the amounts of gel are greater than with nonstructural blacks, for the same amount of black added. 3. The amount of gel is greater in synthetic than in natural rubber mixtures. 4. More intense extraction conditions do not cause disappearance of the gel, but increase the amount of bound rubber and decrease the amount of carbon in the gel. 5. The carbon-rubber gels formed from structural carbons contain larger amounts of bound rubber. 6. It is suggested that bond stability between carbon black particles (characterized by the formation of a carbon black structure) is one of the basic causes of carbon-rubber gel formation.

Free-Radical Activity of Reinforcing Rubber Fillers

1955 ◽  
Vol 28 (2) ◽  
pp. 596-597
Author(s):  
V. A. Garten
Keyword(s):  
Free Radical ◽  
Three Dimensional ◽  
Rubber Matrix ◽  
Radical Mechanism ◽  
Radical Intermediates ◽  
Free Radical Mechanism ◽  
Bound Rubber ◽  
Methylene Groups ◽  
Free Radical Activity ◽  
Vulcanization Process

Abstract In our studies of the mechanism of rubber reinforcement, we were led to assume that primary valency bonds are likely to form between an “active” filler and the rubber-matrix via free-radical intermediates. The hypothesis was based on the following considerations. (1) Although a strong school of thought still maintains that the strength of bonding depends mainly on van der Waals forces, and therefore on particle size, a number of individual observations suggest the presence of “reactive sites” and formation of strong bonds of a chemical nature between filler and rubber. Foremost among these is the phenomenon that the incorporation of active pigments such as carbon blacks, silicas and the like into rubber results in the insolubilization of a part of the rubber. This part is conveniently called “bound rubber” or “carbon-gel”. (2) Farmer and his school have shown that the vulcanization process is based on a free-radical mechanism, wherein a number of the rubber double-bonds and α-methylene groups, sulfur and accelerator are involved, resulting in the formation of three-dimensional giant networks. The mechanism of mastication is also known to consist of the production of free radicals in the presence of suitable ‘radical acceptors’, such as oxygen. (3) There are some common features in both reinforcement and vulcanization, such as crystallization effects. (4) Little or no reinforcing action of otherwise active pigments is observed with saturated polymers, for example, polyisobutylene.

Chemical Interaction between Carbon Black and Elastomers — Crosslinking of Chlorosulfonated Polyethylene by Carbon Black

1994 ◽  
Vol 67 (4) ◽  
pp. 662-671 ◽  
Author(s):  
A. Roychoudhury ◽  
S. K. De ◽  
P. P. De ◽  
J. A. Ayala ◽  
G. A. Joyce
Keyword(s):  
Carbon Black ◽  
Elevated Temperatures ◽  
Chemical Interaction ◽  
Surface Oxidation ◽  
Rubber Content ◽  
Chlorosulfonated Polyethylene ◽  
Surface Sites ◽  
Bound Rubber ◽  
Thermometric Titration ◽  
Oxidized Carbon

Abstract Surface oxidation of a carbon black leads to an increased elastomer-filler bonding between the chlorosulfonated polyethylene and the carbon black. The increased interaction appears to be related to the increased concentration and reactivity of the oxygen containing sites in the oxidized carbon black, as deduced from the moisture adsorption and thermometric titration results. The bound rubber content is substantially higher for the oxidized carbon black. The reactive surface sites of the carbon black also promote the crosslinking of the elastomer at elevated temperatures.

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