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

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.

1997 ◽  
Vol 70 (4) ◽  
pp. 624-633 ◽  
Author(s):  
Ajoy K. Manna ◽  
P. P. De ◽  
D. K. Tripathy ◽  
S. K. De ◽  
M. K. Chatterjee

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.


1992 ◽  
Vol 65 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Siegfried Wolff ◽  
Meng-Jiao Wang

Abstract Carbon black N110 and a precipitated silica, which have comparable surface area and structure, were selected as model fillers to study the effect of filler surface energies on rubber reinforcement. In comparison with carbon black, the surface energies of silica are characterized by a lower dispersive component, γsd, and higher specific component, γssp. It was found that the high γssp of silica leads to strong interaggregate interaction, resulting in higher viscosity of the compounds, higher αƒ, and higher moduli of the vulcanizates at small strain. The higher γsd of carbon black, in contrast, causes strong filler—polymer interaction, which is reflected in a higher bound-rubber content of the compounds and higher moduli of the vulcanizates at high elongation.


2016 ◽  
Vol 89 (4) ◽  
pp. 640-652 ◽  
Author(s):  
Manuchet Nillawong ◽  
Pongdhorn Sae-oui ◽  
Krisda Suchiva ◽  
Chakrit Sirisinha

ABSTRACT Compounds of SBR incorporated with hybrid filler of carbon black (CB) and aramid pulp were prepared. The ratio of CB to aramid pulp was varied and its effects on viscoelastic and mechanical properties of the rubber were investigated. Two aramid pulp types were used in this study: conventional aramid pulp (CAP) and the predispersed aramid pulp (PAP). The rubber–filler interaction as indicated by bound rubber content decreases with increasing aramid pulp loading, regardless of the aramid pulp type. This results in a decrease in tensile and abrasion properties with increasing fiber loading. The energy dissipation properties of the hybrid composites are also poorer than those of the CB/SBR composite, as reflected by the heat buildup values. Use of predispersed aramid fiber resulted in improved dispersion of the fiber in SBR. Thus, Mooney viscosities of the PAP-filled systems are lower than those of the CAP-filled systems, but the percentages of elongation at breaks are higher. The distinct feature of aramid fiber/CB hybrid SBR composites is their high moduli over an extended range of temperatures up to 80°C that is unattainable with the use of CB alone.


1974 ◽  
Vol 2 (3) ◽  
pp. 211-228 ◽  
Author(s):  
G. R. Cotten ◽  
E. M. Dannenberg

Abstract Prediction of tread wear from laboratory tests can be a valuable guide in the development of improved carbon blacks and controlling the quality of normal production. We have developed two tests which give good correlation with actual road wear data on over 100 experimental blacks. One test involves running Akron angle abrasion on a compound with only 30 phr of carbon black where differences in abrasion resistance are magnified. The other test measures surface activity towards the polymer by determining bound rubber content of a heat-treated nonproductive mix. By using both tests together, tread wear ratings of blacks used in this study could be predicted almost as well as by a single, controlled, multisectional road test with five tires run for 8000–10,000 miles.


2000 ◽  
Vol 73 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Jihuai Wu ◽  
Zhen Shen ◽  
Donghong Hu ◽  
Jinling Huang ◽  
Naisheng Chen

Abstract The bound rubber measurement method was improved by ethylenediamine (NH2-CH2-CH2-NH2) replacing ammonia (NH3) as the basic agent. Using the new method, the influence of organic base on bound rubber content was investigated, the relation between bound rubber content and the mechanical properties of the silicone rubber filled with modified ultrafine mineral powder was studied, and the interaction between silicone rubber matrix and mineral filler was discussed. As a result, it is suggested that chemical interaction plays the main role in the bound rubber of silicone filled with modified ultrafine mineral powder.


1990 ◽  
Vol 63 (5) ◽  
pp. 747-778 ◽  
Author(s):  
J. A. Ayala ◽  
W. M. Hess ◽  
A. O. Dotson ◽  
G. A. Joyce

Abstract A series of carbon blacks of widely varying morphology and microstructure were analyzed for surface compositional properties employing SIMS, XPS/ESCA, and GC-MS. These studies were supported by bulk analyses for hydrogen and oxygen content. Surface reactivity was assessed by means of inverse gas chromatography, moisture adsorption, and oxidation in an oxygen plasma. To directly assess carbon-black-polymer interaction, the carbon blacks were evaluated in SBR and IIR compounds for stress-strain and dynamic properties as well as bound rubber. The major findings of these studies are: 1. The combined results of hydrogen content, SIMS, and pyrolysis-GC-MS suggest a complex hydrogen functionality at the carbon-black surface, which governs the level of interaction with elastomers. 2. SIMS analyses have shown that the hydrogen functionality at the carbon-black surface is preserved after an 1173 K heat treatment in an inert atmosphere. 3. Gas-solid chromatography results indicate that this technique may be very useful to determine the degree of heterogeneity of a carbon-black surface. It also provides a tool to characterize the nature of the surface sites which are responsible for such a heterogeneity. 4. Moisture-adsorption rates provides a means to explore the reactivity of carbon-black-surface sites. Initial rates of adsorption can be well explained by a second-order-rate mechanism. 5. Bound-rubber development (SBR) and oxygen content per square meter of carbon-black-surface area were directly proportional to the hydrogen content of the black. The hydrogen content is considered to be the primary compositional factor relating to carbon-black-surface activity, while bound rubber and oxygen levels are specific measures of surface reactivity. 6. The slope of the stress-strain curves (or the modulus value) in the λ=1 to 3 region divided by the black networking factor, η (E′ at 2% ptp ÷ at 25% ptp), is sensitive to changes in black-polymer interaction. This ratio (σ/η or M/η) shows an excellent correlation with black hydrogen content and bound rubber (SBR). 7. The σ/η values for SBR and IIR are highly correlated, although the values for SBR are two to three times higher, and there was no measurable bound rubber for any of the IIR compounds. 8. The σ/η values for IIR (λ=2−3) and the oxygen/m2 values were found to be the best discriminators for black-polymer interaction in explaining within-grade treadwear variations in SBR/BR multisection radial-passenger treads.


1995 ◽  
Vol 68 (5) ◽  
pp. 815-823 ◽  
Author(s):  
A. Roychoudhury ◽  
P. P. De ◽  
N. Roychoudhury ◽  
A. Vidal

Abstract The surface of precipitated silica was modified by heat treatment (800°C, 4 h) and hexadecanol treatment. Diffuse reflectance infrared Fourier transform spectroscopic (DRIFTS) measurements reveal that the modification of the silica surface reduces the silanol content. Heat treatment causes condensation of the silanol groups forming siloxane linkages, while hexadecanol treatment causes esterification, thereby, shielding the free silanol groups. As a result, the modified silicas exhibit much less interaction with polar molecules (e.g. water, chloroform), compared to the unreacted silica. Bound rubber formation in the chlorosulfonated polyethylene (CSM)/silica system is also adversely affected by the modification of the filler surface. CSM upon heat treatment (180°C, 1 h) loses -SO2Cl groups and the modified polymer lacks in its ability to form bound rubber. Accordingly, it is believed that the rubber-filler interaction occurs between the silanol groups of the silica and sulfonyl chloride groups of CSM.


1969 ◽  
Vol 42 (3) ◽  
pp. 858-873 ◽  
Author(s):  
A. M. Gessler

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.


1975 ◽  
Vol 48 (4) ◽  
pp. 548-557 ◽  
Author(s):  
G. R. Cotten

Abstract 1. A direct correlation between bound rubber content and molecular weight of soluble polymer was found for a wide range of carbon black samples and processing conditions in SBR. 2. No significant polymer degradation occurred during the ineorporation of carbon black into SBR rubber. 3. A theory was proposed to explain the observed changes in viscosity and extrusion shrinkage of rubber stocks. This theory is based on the concept of occluded rubber which is rich in high molecular weight polymer and behaves as a part of filler volume during viscous flow.


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