Filler—Elastomer Interactions. Part IV. The Effect of the Surface Energies of Fillers on Elastomer Reinforcement

1992 ◽  
Vol 65 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Siegfried Wolff ◽  
Meng-Jiao Wang
Keyword(s):  
Carbon Black ◽  
Small Strain ◽  
Rubber Content ◽  
Specific Component ◽  
Dispersive Component ◽  
Surface Energies ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
High Elongation ◽  
Polymer Interaction

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.

Filler—Elastomer Interactions. Part III. Carbon-Black-Surface Energies and Interactions with Elastomer Analogs

1991 ◽  
Vol 64 (5) ◽  
pp. 714-736 ◽  
Author(s):  
Meng-Jiao Wang ◽  
Siegfried Wolff ◽  
Jean-Baptiste Donnet
Keyword(s):  
Surface Energy ◽  
Carbon Black ◽  
Surface Area ◽  
Particle Interaction ◽  
Crystallographic Structure ◽  
Specific Component ◽  
Dispersive Component ◽  
Carbon Blacks ◽  
Surface Energies ◽  
Very High

Abstract The surface energies, both the dispersive component, γsd, and the specific component, γssp, of dry- and wet-pelletized carbon blacks, ranging from N110 to N990, were evaluated by inverse gas-solid chromatography at infinite dilution. The results indicate that the dispersive components of the surface energy of carbon blacks increase with increasing surface area. This dependence may essentially reflect an effect of microstructure on the surface energies, which can be confirmed by the relationship between the crystallographic parameters of crystallites and the graphitization of the carbon blacks. It was found that smaller crystallites characterized by a lower value of Lc lead to higher surface energy, whereas graphitization of the carbon black points toward lower surface energy, perhaps resulting from the growth of the quasi-graphite structure. Surface area dependence of the specific component of the surface energy characterized by the specific energy of adsorption of a polar probe follows the same pattern as was observed for the dispersive component, i.e., γsd increases with surface area. This is believed to be related to the crystallographic structure and the surface chemistry. Studies on adsorption energies of the low-molecular-weight analogs of elastomers generally show that the interactions between carbon blacks and rubbers depend not only on filler surface energies but also on the structure of the elastomers. Due to their polar functional groups, NBR and SBR show a stronger interaction with blacks than unsaturated rubbers. Among the rubbers simulated, IIR would have the lowest interaction with the filler. A comparison of the surface energies of carbon blacks and silicas points toward a very high γsd, for blacks which may show strong interaction with nonpolar- or low-polar polymers, while the very high Sf value of the silicas, especially precipitated silicas, a measure of the relative polarity of their surface, is considered to be representative of strong particle-particle interaction, leading to the formation of a filler network.

PROPERTIES OF SBR FILLED WITH CARBON BLACK AND ARAMID PULP HYBRID FILLER: COMPARISON BETWEEN PREDISPERSED ARAMID PULP AND CONVENTIONAL ARAMID PULP

2016 ◽  
Vol 89 (4) ◽  
pp. 640-652 ◽  
Author(s):  
Manuchet Nillawong ◽  
Pongdhorn Sae-oui ◽  
Krisda Suchiva ◽  
Chakrit Sirisinha
Keyword(s):  
Carbon Black ◽  
Hybrid Composites ◽  
Aramid Fiber ◽  
Rubber Content ◽  
Hybrid Filler ◽  
Fiber Loading ◽  
Bound Rubber ◽  
Extended Range ◽  
Heat Buildup ◽  
Rubber Filler

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.

A Method for Evaluation of Carbon Blacks and Correlation with Road Wear Ratings

1974 ◽  
Vol 2 (3) ◽  
pp. 211-228 ◽  
Author(s):  
G. R. Cotten ◽  
E. M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Abrasion Resistance ◽  
Laboratory Tests ◽  
The Other ◽  
Rubber Content ◽  
Carbon Blacks ◽  
Heat Treated ◽  
Bound Rubber ◽  
Normal Production

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.

New Studies on the Surface Properties of Carbon Blacks

1990 ◽  
Vol 63 (5) ◽  
pp. 747-778 ◽  
Author(s):  
J. A. Ayala ◽  
W. M. Hess ◽  
A. O. Dotson ◽  
G. A. Joyce
Keyword(s):  
Carbon Black ◽  
Hydrogen Content ◽  
Surface Reactivity ◽  
Moisture Adsorption ◽  
Carbon Blacks ◽  
Surface Sites ◽  
Bound Rubber ◽  
Carbon Black Surface ◽  
Black Surface ◽  
Polymer Interaction

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.

Swelling Behavior of Rubbers Compounded with Reinforcing Pigments

1959 ◽  
Vol 32 (3) ◽  
pp. 825-843 ◽  
Author(s):  
B. B. S. T. Boonstra ◽  
Eli M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Fumed Silica ◽  
Crosslink Density ◽  
The Other ◽  
Rubber Matrix ◽  
Volume Loading ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
Equilibrium Swelling ◽  
The Matrix

Abstract Equilibrium swelling data are presented for vulcanizates of natural rubber, SBR 1500, butyl rubber, neoprene, and nitrile rubber containing fumed silica, precipitated silica, precipitated calcium metasilicate, hard clay and carbon black. Swelling media are chloroform, benzene, hexane, and acetone. It is observed that certain fillers, particularly carbon black, cause a reduction in the swelling of the rubber matrix which is commensurate with the volume loading of the filler. This effect is not specific for a particular solvent or elastomer. When a series of loadings of a filler shows this effect of reducing the matrix swelling in one solvent, it is also shown by the swelling data for the other solvents, but not to the same degree. The system SBR-benzene was studied to determine from the bound rubber measurements and the equilibrium swelling data for the corresponding vulcanizates the number of crosslinks per cubic centimeter in the unvulcanized and vulcanized states. It appears that the number of crosslinks estimated in the bound rubber gel is much too small to account for the increase in crosslink density in the rubber matrix that is caused by the presence of carbon black in the vulcanizate.

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.

Influence of Carbon Black on Process-Ability of Rubber Stocks. I. Bound Rubber Formation

1975 ◽  
Vol 48 (4) ◽  
pp. 548-557 ◽  
Author(s):  
G. R. Cotten
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Polymer Degradation ◽  
Processing Conditions ◽  
Rubber Content ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Bound Rubber ◽  
Wide Range ◽  
Process Ability

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.

Carbon-Black-Elastomer Interaction

1991 ◽  
Vol 64 (1) ◽  
pp. 19-39 ◽  
Author(s):  
J. A. Ayala ◽  
W. M. Hess ◽  
F. D. Kistler ◽  
G. A. Joyce
Keyword(s):  
Carbon Black ◽  
Surface Activity ◽  
Chemical Reactivity ◽  
Surface Reactivity ◽  
Moisture Adsorption ◽  
Carbon Blacks ◽  
Bound Rubber ◽  
Carbon Black Surface ◽  
Black Surface ◽  
Polymer Interaction

Abstract A number of different techniques were applied to measure carbon-black-surface reactivity and the level of black-polymer interaction in four different elastomer systems (SBR, IIR, NR, and NBR) representing differences in unsaturation, crystallinity and polarity. Known within-grade surface activity variations were based on partial graphitization of an N121-type carbon black. The surface activity of different black grades was studied as a function of variations in both surface area and DBPA. Direct measurements of carbon-black-surface reactivity were based on hydrogen analysis, SIMS, IGC, and moisture adsorption. In-rubber measurements included bound rubber, SIMS of cut surfaces, and an interaction parameter, σ/η, which is derived from the slope (σ) of the stress-strain curve at low elongations, and (η), the ratio of dynamic modulus (E′) at 1% and 25% DSA. The following trends were observed: 1. The σ/η values provided a good measure of black-polymer interaction in all four polymer systems for either the within-grade or across-grade comparisons. 2. Higher σ/η values were indicated for SBR and NBR, followed by NR and IIR in that order. 3. SBR indicated the greatest sensitivity for bound-rubber measurements in terms of distinguishing within-grade variations in black-polymer interaction, followed by IIR, NR, and NBR in that order. 4. Positive SIMS on dry carbon black indicates the presence of complex hydrocarbon structures suitable for chemical reactivity at the carbon-black surface. 5. SIMS analyses on the dry carbon blacks exhibited intensity variations in the negative hydrocarbon fragments which were in line with the within-grade variations in hydrogen content. 6. SIMS analyses on the cut-rubber compound surfaces showed overall variations in intensity which were proportional to the range and level of the bound-rubber measurements. The most meaningful variations were recorded for SBR and IIR. 7. Heats of adsorption derived from IGC measurements with different adsorbates showed an excellent correlation with black-polymer interaction for the within-grade studies. Measurements across grades did not correlate as well with the in-rubber measurements, but the best results were obtained using styrene as the adsorbate. 8. The within-grade moisture adsorption measurements showed excellent agreement with IGC and the other techniques for the N121 series of heat-treated carbon blacks.

Influence of Fillers Surface Characteristics on Bound Rubber Properties of Filled Natural Rubber Compounds

2013 ◽  
Vol 845 ◽  
pp. 412-416 ◽  
Author(s):  
Mustafa Kamal Mazlina
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Surface Activity ◽  
Specific Activity ◽  
Filler Particle ◽  
Surface Characteristics ◽  
Rubber Content ◽  
Rubber Compounds ◽  
Bound Rubber ◽  
Service Application

One of the most important phenomena in rubber science is the reinforcement by rigid entities, such as carbon black, clays, silicates and calcium carbonate. Thus, these fillers are added to rubber formulations to optimise properties that meet a given service application or set of performance parameters. Fillers can be divided into three categories reinforcing, semi-reinforcing and non-reinforcing. For a given elastomer and state of mix, bound rubber can be considered as a measurement of a surface activity of a filler and is considered as one of major factors in reinforcement. A strong rubber: filler interaction results in a large bound rubber content. Good dispersions and distribution of filler aggregates is also important for the full reinforcing potential of fillers to be reached. In this study, the influence of fillers on bound rubber content of Natural Rubber compounds were determined and compared. Results showed that the bound rubber content followed the trend of Carbon Black>Silica>Carbon Black>Starch. The two main filler characteristics that affect the bound rubber properties are the filler particle size and surface activity. The specific activity of the filler is determined by the physical and chemical nature of the filler surface in relation to that of elastomer. Keywords: reinforcement, surface energy

Effect of Epoxidation Level in Silica Filled Epoxidized Natural Rubber Compound on Cure, Rheological, Mechanical and Dynamic Properties

2014 ◽  
Vol 554 ◽  
pp. 71-75 ◽  
Author(s):  
Afnan Aiman Rohadi ◽  
Abdul Razak Rahmat ◽  
Mazlina Mustafa Kamal
Keyword(s):  
Natural Rubber ◽  
Dynamic Properties ◽  
Small Deformation ◽  
Epoxidized Natural Rubber ◽  
Rubber Content ◽  
Silanol Groups ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
Spectroscopy Studies ◽  
Work Effect

Reinforcement of rubber by precipitated silica is adversely affected due to lack of strong polymer silica bonding. Functionalized polymers interact strongly with surface silanol groups of precipitated silica. In this work, effect of variation of epoxide content in silica filled Epoxidized Natural Rubber (ENR) compound was studied namely ENR 10, 25, 37.5 and 50mol%. Increasing in epoxide level of rubber has contributed to better rubber filler interaction and lead to better mechanical properties. Meanwhile, ENR’s with greater degree of polarity has contributed significantly to higher storage moduli at small deformation and also leads to increase in bound rubber content value. Fourier transform infrared spectroscopy studies showed that the silanol groups in silica interact with ENR through formation of Si-OH bond.

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