Elastomer Blend Properties—Influence of Carbon Black Type and Location

1977 ◽  
Vol 50 (2) ◽  
pp. 301-326 ◽  
Author(s):  
W. M. Hess ◽  
V. E. Chirico
Keyword(s):  
Fatigue Life ◽  
Carbon Black ◽  
Wide Distribution ◽  
Continuous Phase ◽  
Unit Size ◽  
Polymer Phase ◽  
Tear Strength ◽  
Lower Heat ◽  
Heat Buildup ◽  
Tear Resistance

Abstract Criteria for minimizing hysteresis in carbon-black-filled elastomer blends are: (1) large black unit size, wide distribution, and low structure; (2) higher black loading in the discrete polymer phase (large zones); and (3) polymer of lower hysteresis as the continuous phase (low black loading). Of the different strength properties that were evaluated, tear and fatigue resistance showed the greatest dependence on black location in NR-BR and NR-SBR blends. Both properties were markedly higher for NR-BR, with most of the black in the NR phase. In NR-SBR, tear strength was higher with high loadings of black in the SBR. Fatigue life showed a reverse pattern, but the variations were not as great in this system. Criteria for maximizing tear resistance are: (1) small black unit size, low structure; (2) higher loading of carbon black in the continuous polymer phase ; and (3) the polymer of higher strength as the continuous phase. There may also be optimum levels of polymer zone size and black size distribution which affect tear strength. Optimized performance in a 50:50 NR-BR radial truck tire tread stock was obtained with a wide-distribution N-375 (50:50 N-351-N-110 blend) black with 75% location in the NR phase. This black gave 5–6°C lower heat buildup, equivalent modulus, 35% higher tear strength, and almost double the fatigue life of a conventionally mixed N-220 at essentially equivalent tread wear resistance (−4%). Optimized performance in 50:50 NR-SBR was indicated for a wide-distribution N-231 type (50:50 blend of N-351-N-119) with 75% of the black in the SBR phase. In comparison to conventionally mixed N-234 and N-220, this black gave about 8–10°C lower heat buildup, about 15% lower modulus, and essentially equal tensile, tear, and fatigue properties. Alternatively, a standard N-231 type with 75% location in the NR phase showed about 5–6°C lower heat buildup, about 20% lower modulus, equivalent tensile strength, 60% higher tear resistance, and 75–120% higher fatigue life.

Carbon Black in NR/BR Blends for Truck Tires

1985 ◽  
Vol 58 (2) ◽  
pp. 350-382 ◽  
Author(s):  
W. M. Hess ◽  
P. C. Vegvari ◽  
R. A. Swor
Keyword(s):  
Fatigue Life ◽  
Carbon Black ◽  
Phase Distribution ◽  
Dynamic Properties ◽  
Performance Criteria ◽  
Polymer Phase ◽  
Tear Strength ◽  
Truck Tires ◽  
Bound Rubber ◽  
Heat Buildup

Abstract A series of ten commercial tread-grade carbon blacks were evaluated in a 60/40 NR/BR truck tire tread formulation. A number of important physical properties and performance criteria were assessed in terms of carbon black surface area and DBPA. Significant response equations were obtained for viscosity, bound rubber, resilience, heat buildup, tear strength, and dynamic properties. Dynamic modulus showed a much greater dependence on DBPA in comparison to previous studies on SBR/BR compounds. In a second designed experiment, a single carbon black (N299) was studied as a function of the NR/BR ratio and the amount of carbon black added to the BR phase. The BR black loading was varied at 30, 60, and 90 phr using separate masterbatches which were blended with NR-black masterbatches to give the same final composition for all of the compounds. Properties such as resilience, heat buildup, fatigue life, and tear strength were all improved in the direction of higher loadings of carbon black in the NR phase. A high loading of black in the BR phase caused low bound-rubber development and poor dispersion. This was found to be related to the viscosity ratio of the separate masterbatches. NR to BR viscosity ratios of about 1 to 3 produced good dispersion and high bound rubber. When the BR masterbatch viscosity was two to three times higher than the NR masterbatch, however, dispersion and bound-rubber development dropped sharply at the same total mixing energy. Low hysteresis properties were found to be most dependent on high bound-rubber development, with polymer phase distribution having a relatively minor influence. In contrast, tear strength and fatigue life reached their maximum levels when the NR was the more continuous polymer phase. High bound rubber also appears to enhance tear strength and fatigue life by improving the microdispersion of the carbon black.

Tire tread rubber compounds with ternary system filler based on carbon black, silica, and metakaolin: Contribution of silica/metakaolin content on the final properties

2019 ◽  
Vol 51 (7-8) ◽  
pp. 712-726 ◽  
Author(s):  
Cléverson Fernandes Senra Gabriel ◽  
Alessandra de Alencar Padua Gabino ◽  
Ana Maria Furtado de Sousa ◽  
Cristina Russi Guimarães Furtado ◽  
Regina Célia Reis Nunes
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rolling Resistance ◽  
Partial Substitution ◽  
Negative Effects ◽  
Rubber Compounds ◽  
Lower Heat ◽  
Tread Rubber ◽  
Heat Buildup

Carbon black and high performance silica have been widely employed as binary system filler in tire tread formulations. This study evaluated the total and partial substitution of silica by metakaolin (MK) on the properties of tread rubber composites. Dynamic mechanical thermal analysis and abrasion tests were conducted as typical assessments of tire tread performance: rolling resistance (fuel consumption), wet traction (safety), and abrasion (durability). Further the energy spent by the equipment during the processing of formulations was also analyzed, as well as rheological and mechanical properties. A significant reduction of rolling resistance was obtained with 75% and 100% of silica substitution by MK, which could lead to lower heat buildup in tire tread applications, without showing negative effects on wet traction, although abrasion showed undesired results. The substitution of silica by MK also lowered energy demanded for processing. No major changes were observed in vulcanization parameters and mechanical properties, which is interesting considering the fact that MK is nonreinforce filler.

EFFECTS OF BLEND RATIO AND SBR TYPE ON PROPERTIES OF SILICA-FILLED SBR/NR TIRE TREAD COMPOUNDS

2016 ◽  
Vol 89 (2) ◽  
pp. 240-250 ◽  
Author(s):  
Pongdhorn Sae-oui ◽  
Krisda Suchiva ◽  
Uthai Thepsuwan ◽  
Wenussarin Intiya ◽  
Pram Yodjun ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Rolling Resistance ◽  
Skid Resistance ◽  
Blend Ratio ◽  
Elongation At Break ◽  
Tear Strength ◽  
Cure Time ◽  
Lower Heat ◽  
Heat Buildup ◽  
Wet Skid Resistance

ABSTRACT The influences of blend ratio between SBR and NR and SBR type, emulsion SBR (E-SBR) and solution SBR (S-SBR), on properties of silica-filled passenger car tire tread–based compounds were investigated. Results reveal that, with increasing NR proportion, cure time and most mechanical and dynamic properties, for example, tensile strength, tear strength, modulus, abrasion resistance, and wet skid resistance of the compounds and vulcanizates, are reduced, whereas the improvements in elongation at break and crack growth resistance are observed. The unexpectedly impaired mechanical and dynamic properties identified in the presence of NR are mainly caused by thermal degradation of NR taking place during the mixing process at high temperature. Compared with E-SBR, S-SBR provides superior properties in many aspects, that is, higher modulus and greater abrasion and wet skid resistances as well as lower heat buildup and rolling resistance. However, E-SBR gives greater tear strength than S-SBR.

Measurement of Carbon Black Dispersion in Rubber by Surface Analysis

1978 ◽  
Vol 51 (4) ◽  
pp. 817-839 ◽  
Author(s):  
P. C. Vegvari ◽  
W. M. Hess ◽  
V. E. Chirico
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
Fatigue Life ◽  
Carbon Black ◽  
Distinct Advantage ◽  
Dispersion Index ◽  
Programmable Calculator ◽  
Wide Range ◽  
Heat Buildup ◽  
Carbon Black Dispersion

Abstract A stylus-type surface roughness tester has been applied to the study of carbon black dispersion in a number of different rubber systems. The method is based on a freshly cut rubber surface which is tracked by the stylus to provide a roughness trace on a strip chart. Carbon black agglomerates deflect the cut path because of their higher hardness relative to the surrounding matrix. Thus, surface roughness diminishes at increasing levels of dispersion. A quantitative index of dispersion quality may be derived from the frequency and average height of the roughness peaks. The method offers a distinct advantage over previous methods in its ability to provide precise dispersion ratings over a very wide range of rubber processing levels from the masterbatch to the final product. The technique is applicable to the analysis of unvulcanized rubber compounds and could be utilized as a factory quality control procedure. Direct interfacing of the surface analyzer to a programmable calculator would provide quantitative dispersion ratings within five minutes of the receipt of a sample. Studies of varied carbon black dispersions in SBR and SBR/BR passenger tread formulations have confirmed the work of previous authors. Tensile strength, fatigue life, resilience, elongation, and extrusion shrinkage increased at higher dispersion levels, while Mooney viscosity, Shore hardness and heat buildup exhibited a progressive decrease. The properties of a 50/50 NR/BR truck tread formulation showed a more varied response to black dispersion. Tensile strength and resilience showed considerably less dispersion dependence than SBR and SBR/BR. However, the tensile response increases with increasing black fineness and decreasing structure, while resilience showed the opposite trend. Fatigue life and heat buildup showed the same trends observed for SBR and SBR/BR. However, NR/BR treadwear (radial tires) showed considerably less dependence on dispersion above the 70% level, in comparison to those other polymers (bias ply tires). NR/BR with N220 at a dispersion index of 68 gave treadwear resistance that was equivalent to the same compound at a dispersion index of 89. However, dispersion indices of 50 or lower caused severely depressed treadwear resistance for the different blacks that were tested. The milling of NR/BR masterbatches cooled overnight produced significantly higher dispersion levels in comparison to hot batches at the same total mixing energy. This procedure can be employed to optimize treadwear and other properties at lower levels of energy consumption.

Effect of Diameter and Surface Area of Carbon Black Particles on Certain Properties of Rubber Compounds

1944 ◽  
Vol 17 (2) ◽  
pp. 451-474
Author(s):  
D. Parkinson
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Carbon Black ◽  
Abrasion Resistance ◽  
Particle Diameter ◽  
Stiffness Modulus ◽  
Carbon Structures ◽  
Rubber Compounds ◽  
Regular Manner ◽  
Tear Resistance

Abstract Carbon blacks can be grouped into different classes according to the way in which their fineness of division relates to different properties in rubber. Within any one class the principal properties vary in a regular manner with particle size. The normal class consists of the furnace carbons, Kosmos (Dixie)-40, Statex, the rubber-grade impingement carbons, and possibly, the color-grade impingement carbons. The subnormal classes consist of thermal carbons and acetylene and lamp blacks. Irrespective of the above classification, the properties which depend more on fineness of division than on other factors are rebound resilience, abrasion resistance, tensile strength and tear resistance. The lower limit of particle diameter for best tensile strength and tear resistance appears to be higher than that for abrasion resistance. B.S.I, hardness and electrical conductivity are properties which depend at least as much on other factors as on particle size. Stiffness (modulus) depends more on other factors than on particle size. Factors modifying the effects of particle size (or specific surface) include the presence of carbon-carbon structures and a reduction in strength of bond in rubber-carbon structures. Carbon black is thought to exist in rubber in four states: agglomerated, flocculated, dispersed, and bonded to the rubber molecules (the reënforcing fraction). Abrasion resistance is regarded as providing the only reliable measure of reënforcement.

Effect of Carbon Black Reinforcing Fillers on Mechanical Properties of NBR Materials Used for the Progressing Cavity Pump

2015 ◽  
Vol 750 ◽  
pp. 339-344 ◽  
Author(s):  
Long Pan ◽  
Jin Zhu Tan ◽  
Liu Fei Fan ◽  
Xue Mei Han
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Black ◽  
Heat Resistance ◽  
Tear Strength ◽  
Resistance Property ◽  
Reinforcing Fillers ◽  
Materials Used

Three kinds of reinforcing fillers (i.e. carbon black N330, carbon black N880 and carbon-white) were used to study effect of the reinforcing fillers on the mechanical properties of NBR materials. The NBR materials with various reinforcing fillers were fabricated, and the mechanical property tests were performed in this work. The results show that the carbon black N330 made the NBR material have better tensile strength, hardness, elongation and compression elastic modulus compared to the carbon black N880 and the carbon-white, while the carbon-white made NBR material have better heat resistance, tear strength and elongation compared to the carbon black N330 and the carbon black N880. In addition, the tensile strength, tear strength, elongation and the heat resistance property of the NBR materials increased significantly with the increase of the carbon-white, but the compression elastic modulus decreased with the increase of the carbon-white.

A Method to Resolve the Properties of Individual Phases in Carbon-Black-Loaded Elastomer Blends

1991 ◽  
Vol 64 (2) ◽  
pp. 234-242
Author(s):  
R. F. Bauer ◽  
A. H. Crossland
Keyword(s):  
Carbon Black ◽  
Large Deformation ◽  
Polymer Phase ◽  
Stress Strain ◽  
Strain Behavior ◽  
Stress Behavior ◽  
Strain Relationship ◽  
Deformation Stress ◽  
The Individual ◽  
Vulcanization Process

Abstract Properties of the individual phases in a 70/30 carbon-black-loaded BR/NR blend could be successfully resolved using large deformation stress-strain modelling. Since the dispersed NR phase of the example had a lower modulus than the continuous BR phase, the interaction between the blend phases could be modelled by a simple parallel coupling arrangement. The stress behavior of each individual carbon-black-loaded polymer phase was then determined with respect to strain using a specially derived stress-strain relationship. The blend components also have to be characterized with respect to state-of-cure by empirically establishing how the parameters in the stress-strain relationship vary with respect to cure. The properties of the phases in the blend are then determined by finding the combination of component parameters which precisely reproduce the stress-strain behavior of the blend. In the demonstration example of this paper, there was evidence of a significant amount of curative migration between phases during the vulcanization process.

Carbon Black in Rubber Insulating Compounds

1930 ◽  
Vol 3 (4) ◽  
pp. 733-742
Author(s):  
W. B. Wiegand ◽  
C. R. Boggs
Keyword(s):  
Dielectric Properties ◽  
Electrical Properties ◽  
Carbon Black ◽  
Power Factor ◽  
Dielectric Strength ◽  
Electrical Insulation ◽  
Rubber Content ◽  
Beneficial Effects ◽  
The Wire ◽  
Tear Resistance

Abstract 1—It has been shown that, in conformity with published behavior of other conducting substances (metallic sols, etc.), carbon black may be incorporated in a dielectric such as rubber without detracting from its insulating or dielectric properties. Published results to the contrary were in error, probably because the material was added in excessive amounts. 2—In addition to this effect, it has been shown that the well-known ability of carbon black to adsorb water and dissolved electrolytes endows carbon black???rubber insulating compounds of various types with improved dielectric strength, resistivity, and power factor, the specific inductive capacity remaining substantially unchanged. In some cases this improvement may exceed 50 per cent. 3—The prevailing opinion that carbon black is injurious to rubber insulating compounds which are to be used next to the wire, or which in general are expected to serve as electrical insulation, has been shown to be erroneous, provided the proper proportions are employed. 4—These results would seem to render advisable the rewriting of many specifications dealing with rubber insulating compounds, and thus make it possible to apply the well-known beneficial effects of carbon black compounding—improved toughness, density, wearing resistance, imperviousness to light, tear resistance, etc.—to the electrical insulation field, from which it has hitherto been barred. 5—Although it is strongly recommended that the proper dosage of carbon black (which must be of suitable quality and thoroughly dry) be redetermined in each case, the writers' results would indicate that up to 10 per cent of carbon black on the crude rubber (plus the rubber content of any reclaimed rubber present) will effect the desired improvement in electrical properties.

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