Filler-Elastomer Interactions. Part VIII. The Role of the Distance between Filler Aggregates in the Dynamic Properties of Filled Vulcanizates

1993 ◽  
Vol 66 (2) ◽  
pp. 178-195 ◽  
Author(s):  
Meng-Jiao Wang ◽  
Siegfried Wolff ◽  
Ewe-Hong Tan
Keyword(s):  
Gas Chromatography ◽  
Carbon Black ◽  
Inverse Gas Chromatography ◽  
Dynamic Properties ◽  
Random Packing ◽  
Attractive Potential ◽  
Carbon Blacks ◽  
Filled Rubber ◽  
Tan Δ

Abstract Based on the concepts of the occlusion of rubber and random packing of spheres whose volume is equivalent to that permeated by individual aggregates, an equation was deduced to estimate the distance between carbon-black aggregates in filled rubber. It was found that when the interaggregate distance reaches a critical point which is approximately identical for all carbon blacks investigated (furnace blacks), the elastic modulus measured at very low strain deviates from the modified Guth-Gold equation. Tan δ and resilience are mainly determined by the distance between aggregates. These phenomena are related to filler networking which is determined by the attractive potential and the distance between individual aggregates. Since the factor Sf, used to characterize the strength of secondary filler networks in hydrocarbon rubbers and measured by means of inverse gas chromatography, is approximately the same for all furnace blacks, the interaggregate distance seems to determine filler networking. A comparison of fillers with different Sf (graphitized vs. nongraphitized carbon blacks, carbon black vs. silica) shows that at the same interaggregate distance, a lower Sf leads to higher tan δ of the filled vulcanizates.

Surface Energy of Commercial and Pyrolytic Carbon Blacks by Inverse Gas Chromatography

1997 ◽  
Vol 70 (5) ◽  
pp. 759-768 ◽  
Author(s):  
Hans Darmstadt ◽  
Christian Roy ◽  
Serge Kaliaguine ◽  
Helga Cormier
Keyword(s):  
Gas Chromatography ◽  
Surface Energy ◽  
Carbon Black ◽  
Surface Area ◽  
Inverse Gas Chromatography ◽  
Specific Interaction ◽  
Pyrolytic Carbon ◽  
Dispersive Component ◽  
Carbon Blacks ◽  
Carbonaceous Deposits

Abstract The surface properties of carbon blacks obtained by vacuum pyrolysis of different used rubbers (CBp) and of commercial carbon blacks were measured by inverse gas chromatography (IGC). The dispersive component of the surface energy (γsd) and the specific interaction (Isp) of the recovered CBp were lower than γsd and Isp of the virgin carbon black initially present in the rubber. However, γsd and Isp of recovered medium surface area carbon black and of virgin low-surface-area carbon black were comparable. During the pyrolysis, carbonaceous deposits are formed on the CBp surface. A correlation between γsd and Isp and the amount of the carbonaceous deposits, measured by ESCA, was found, suggesting that the formation of these deposits is responsible for the decrease of γsd and Isp.

Effects of tension fatigue on the structure and properties of carbon black filled-SBR and SBR/TPI blends

2019 ◽  
Vol 40 (1) ◽  
pp. 13-20
Author(s):  
Liu Yang ◽  
Kaikai Liu ◽  
Zijun Gu ◽  
Aihua Du
Keyword(s):  
Carbon Black ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Dynamic Properties ◽  
Fatigue Properties ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Structure And Properties ◽  
Tan Δ ◽  
The Impact

Abstract The aim of this study was to explore the impact of tension fatigue on the structure and properties of filled SBR and SBR/TPI blends. The effect of tension fatigue on the dynamic properties of carbon black-filled styrene-butadiene rubber (SBR) and SBR/trans-1,4-polyisoprene (SBR/TPI) blend vulcanizates were investigated by dynamic mechanical analysis (DMA). The Mooney-Rivlin analysis of tensile stress-strain data is used for the determination of a rubber network crosslink density. The fatigue fracture surface of SBR/TPI vulcanizates was observed with a scanning electron microscopy (SEM). The crystallinity of TPI in carbon black-filled SBR/TPI (80/20) was characterized by X-ray diffraction (XRD). The results showed that the incorporation of TPI into SBR vulcanizates influences the fatigue properties of the blend vulcanizates. The blend vulcanizates showed optimum fatigue properties with 20 phr TPI. With increasing fatigue cycles, the tensile properties and crosslink density of SBR vulcanizates were decreased substantially. Compared with that of SBR vulcanizates, the tensile properties and crosslink density of SBR/TPI (80/20) blend vulcanizates changed little with the increase in fatigue cycles, and tan δ and E′ decreased gradually with the fatigue cycles. There was a sharp decrease in the E′ and tan δ curve in the temperature range of 40 ~ 60°C. The XRD diffraction peak corresponding to 3.9 Å broadened when the fatigue cycles were increased to 1 million times, and a new peak with inter-planar spacing at 7.6 and 4.7 Å appeared.

Antioxidant Properties of Carbon Black in Unsaturated Elastomers. Studies with cis-Polybutadiene

1965 ◽  
Vol 38 (3) ◽  
pp. 636-646
Author(s):  
J. T. Gruver ◽  
K. W. Rollmann
Keyword(s):  
Antioxidant Activity ◽  
Carbon Black ◽  
Antioxidant Properties ◽  
Chain Scission ◽  
Oxygen Absorption ◽  
Hydroxyl Groups ◽  
Carbon Blacks ◽  
Crosslinking Reactions ◽  
Absorption Measurements

Abstract The thermal antioxidant behavior of carbon black was studied in vulcanized cis-polybutadiene and related to the surface chemistry of the black. Continuous and intermittent stress relaxation and oxygen absorption measurements were employed to determine the antioxidant ability of the carbon blacks. The blacks were characterized by the surface concentrations of oxygen-containing functional groups, using methods described in the literature. Antioxidant activity was found to be highest in carbons containing relatively large amounts of bound oxygen. These carbons are also acidic and decompose peroxides by the ionic mechanism. This was demonstrated with cumyl peroxide. However, even though the acidity and ability to decompose cumyl peroxide to phenol and acetone could be destroyed by methylation, this treatment did not seriously impair the antioxidant activity, so that the role of acidic groups appears to be minor. Evidence is presented which suggests strongly that the antioxidant behavior of carbon blacks is due to surface quinones, possibly hydrogen-bonded with adjacent hydroxyl groups. Measurements made on samples vulcanized in peroxide and sulfur curing systems indicate that the antioxidant behavior of carbon black is independent of the method of vulcanization in the absence of other antioxidants. A characteristic feature of the antioxidant action of carbon blacks is their tendency to repress the oxidative crosslinking reactions, the relative amount of compensation of chain scission by crosslinking being smaller than in gum vulcanizates.

Inverse gas chromatography. 2. The role of "inert" support

1985 ◽  
Vol 18 (5) ◽  
pp. 1030-1034 ◽  
Author(s):  
Timothy W. Card ◽  
Zeki Y. Al-Saigh ◽  
Petr Munk
Keyword(s):  
Gas Chromatography ◽  
Inverse Gas Chromatography ◽  
Inert Support

The Role of Filler Networking in Dynamic Properties of Filled Rubber

1999 ◽  
Vol 72 (2) ◽  
pp. 430-448 ◽  
Author(s):  
Meng-Jiao Wang
Keyword(s):  
Dynamic Properties ◽  
Cyclic Strain ◽  
Considerable Change ◽  
Dynamic Strain ◽  
Additional Energy ◽  
Polymer Systems ◽  
Filled Rubber ◽  
Filler Network ◽  
The Impact

Abstract Fillers, when added to polymer systems, are known to cause a considerable change in dynamic properties. For a given polymer and cure system, this paper discusses the impact of the filler network, both its strength and architecture, on the dynamic modulus and hysteresis during dynamic strain. It was found that the filler network can substantially increase the effective volume of the filler due to rubber trapped in the agglomerates, leading to high elastic modulus. The amount of trapped rubber was estimated according to Van der Poel theory. During cyclic strain, while the stable filler network can reduce the hysteresis of the filled rubber, the breakdown and reformation of the filler network would cause an additional energy dissipation resulting in higher hysteresis.

Filler-Elastomer Interactions. Part VI. Characterization of Carbon Blacks by Inverse Gas Chromatography at Finite Concentration

1992 ◽  
Vol 65 (5) ◽  
pp. 890-907 ◽  
Author(s):  
Meng-Jiao Wang ◽  
Siegfried Wolff
Keyword(s):  
Gas Chromatography ◽  
Energy Distribution ◽  
Inverse Gas Chromatography ◽  
General Trend ◽  
High Energy ◽  
Carbon Blacks ◽  
Finite Concentration ◽  
Good Agreement

Abstract Carbon blacks ranging from N110 to N990 were characterized by means of inverse gas chromatography at finite concentration. The isotherms, net heat, and spreading pressures for benzene and cyclohexane adsorption suggest a general trend of increasing surface activity with increases in specific surface area. This is in good agreement with surface-energy measurements reported previously. The energy-distribution function of adsorption shows that while the concentrations of low-energy sites are comparable for most of the carbon blacks, differences exist with regard to high-energy sites. These suggest that small-particle-size blacks possess a greater number of high-energy centers. The graphitization of carbon blacks results in a considerable reduction in their adsorption capacity and narrows the energy distribution of their surfaces. One can therefore conclude that high-energy sites play an important role in the determination of the surface energies and reinforcing ability of carbon blacks.

Volume Change Measurements of Filled Rubber Vulcanizates under Stretching

1970 ◽  
Vol 43 (5) ◽  
pp. 1025-1035 ◽  
Author(s):  
T. Shinomura ◽  
M. Takahashi
Keyword(s):  
Carbon Black ◽  
Volume Change ◽  
Critical Strain ◽  
Curing Time ◽  
Volume Increase ◽  
The Real ◽  
Carbon Blacks ◽  
Strain Pattern ◽  
Filled Rubber ◽  
Rubber Vulcanizate

Abstract The stretching dilatometer of our own design was manufactured, and, using it, we investigated the effects of the types of fillers, the amount of fillers, and the curing time on the volume change phenomena of filled rubber vulcanizates under elongation. It was found that the Δυ/σr (the volume increase induced by the strain divided by the real stress) as a function of γ (the strain) pattern of carbon black loaded rubber vulcanizates was greatly different from that of a whitetex loaded rubber vulcanizate. This phenomenon was explained in the viewpoint of the superposition of the first type and the second type cavitations which had been mentioned in the previous paper. It was found that the critical strain γ0 is dependent upon the carbon black structures, and that the γ0 value decreases while the Δυ value increases with the amount of carbon blacks. It was also found that the Δυ value increases while the Δυ/σr value decreases with curing.

scholarly journals Studies of adsorption of polychlorocarbons on carbon blacks by gas chromatography

1985 ◽  
Vol 2 (4) ◽  
pp. 219-228 ◽  
Author(s):  
E. V. Zagorevskaya ◽  
N. V. Ishchenko ◽  
A. V. Kiselev ◽  
N. V. Kovaleva
Keyword(s):  
Gas Chromatography ◽  
Carbon Black ◽  
Adsorption Properties ◽  
High Adsorption ◽  
Heats Of Adsorption ◽  
Carbon Blacks ◽  
Before And After ◽  
Retention Volumes ◽  
High Adsorption Capacity ◽  
Airborne Chemicals

Adsorption properties of carbon black before and after modification to polyhalogenohydrocarbons, including polyorganochlorine pesticides, have been investigated. It has been shown that graphitised thermal carbon blacks and carbochroms possess high adsorption capacity relative to the above compounds and can be used as supporting adsorbents to analyse these airborne chemicals. Modification raises the selectivity of adsorbents to the compounds being investigated and lowers retention volumes and heats of adsorption, which makes it possible to carry out thermal desorption of the accumulated species at lower temperatures.

Effect of Carbon Black on Hysteresis of Rubber Vulcanizates: Equivalence of Surface Area and Loading

1976 ◽  
Vol 49 (4) ◽  
pp. 1076-1094 ◽  
Author(s):  
J. M. Caruthers ◽  
R. E. Cohen ◽  
A. I. Medalia
Keyword(s):  
Carbon Black ◽  
Surface Area ◽  
Functional Form ◽  
Volume Fraction ◽  
Dynamic Properties ◽  
Dynamic Test ◽  
Practical Interest ◽  
Interfacial Area ◽  
Experimental Conditions ◽  
Tan Δ

Abstract We have developed an empirical correlation between the loss tangent (tan δ) and the product of the volume fraction (ϕ) of carbon black in the composite and the total filler-polymer interfacial area per unit volume of composite (ψ). This correlation was applied to vulcanizates based on SBR-1500, SBR-1712, and NR with various compounding procedures and under different deformation conditions, including forced vibration nonresonant dynamic test machines, and the Goodyear-Healey pendulum rebound. The functional form of the correlation was qualitatively similar in all instances ; however, quantitative aspects of the correlation are dependent upon the particular experimental conditions. Tan δ is a weak function of the deformation amplitude over the region of practical interest. This is in contrast to hysteretic energy loss, which is proportional to the square of the amplitude. The validity of the correlation over wide ranges of amplitude, temperature, and frequency indicates that the viscoelastic relaxation or loss processes are similar over the range of conditions studied. Since the combined parameter, ϕψ, is proportional to ϕ2 multiplied by the specific surface area of the carbon black, this relation implies an equivalence between surface area and loading, with regard to tan 5. It has previously been shown that the elastic modulus depends on structure and loading. Thus, the dynamic properties, including hysteresis under various conditions, can be predicted from the carbon black properties, and compounds can be designed for desired dynamic properties by independent adjustment of loading, structure and surface area.

Low Strain Dynamic Properties of Filled Rubbers

1971 ◽  
Vol 44 (2) ◽  
pp. 440-478 ◽  
Author(s):  
A. R. Payne ◽  
R. E. Whittaker
Keyword(s):  
Carbon Black ◽  
Dynamic Properties ◽  
Fatigue Behavior ◽  
Van Der Waals ◽  
Three Dimensional ◽  
Solid Particles ◽  
Spherical Particles ◽  
Filled Rubber ◽  
Secondary Network ◽  
Filled Rubbers

Abstract Carbon black does not exist as single spherical particles but forms itself into a rodlike primary structure. These rodlike structures then form into an aggregated secondary network. This secondary network is believed to be held together by Van der Waals-London attraction forces. The decrease in shear modulus of filled rubber vulcanizates with strain is due almost certainly to these secondary forces. Special mixing techniques such as attrition of the carbon black, increased time of mixing, or the addition of chemical promoters which aim at dispersing the carbon black within the mix better are shown to decrease the value of G′0−G′∞. The absence of any modulus change with strain for unfilled vulcanizates and secondly the little change observed in values of G′0−G′∞ with increasing vulcanization of the rubber when containing the same amount of carbon black confirms that the decrease in modulus with strain amplitude is in no way associated with the gum phase of the filled vulcanizate. The similarity in behavior of carbon black filled rubbers with clay/water and clay/rubber systems indicates that the decrease in modulus with amplitude is due to the breakdown of the three dimensional filler aggregates. A number of rheological studies on clay systems has confirmed that clay particles form into rigid three dimensional structures when dispersed in a medium. Evidence for the aggregated filler structure to be held together by Van der Waals-London attraction forces comes from the reasonable agreement between the experimental values for the forces required to breakdown the carbon black aggregates in paraffin oil and the forces calculated from Van den Tempel's model for flocculated solid particles in a liquid. The successful application of a domain model to the hysteretical behavior exhibited by carbon black filled vulcanizates at low strains indicates that the carbon black structure breaks down under stress but reforms to the original state when the stress is removed. This conclusion is also supported by the similarity in behavior between filled rubbers and a dendritic crystal structure of PBNA in rubber. Under the optical microscope the PBNA is seen to break down and reform under a stress-strain cycle. The breakdown and reformation of this secondary aggregated carbon black structure increases the hysteresis in filled rubber vulcanizates. Other sources of hysteresis include viscoelasticity of the polymer, crystallization, stress-softening, and changes in network structure (e.g., breakage of weak crosslinks). These mechanisms have been discussed in depth in previous publications. Recent work has shown, however, that the strength of a rubber is dependent on the combined effect of the different hysteretical mechanisms. The breakdown and reformation of the carbon black structure at low strains in filler reinforced rubbers therefore not only affects the heat build up, transmissibility, and fatigue behavior but also influences the failure properties of the filled vulcanizate.

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