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.

Mixing of Carbon Black with Rubber. II. Mechanism of Carbon Black Incorporation

1985 ◽  
Vol 58 (4) ◽  
pp. 774-784 ◽  
Author(s):  
George R. Cotten
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Carbon Black ◽  
Cross Section ◽  
Effective Cross Section ◽  
Rubber Content ◽  
Narrow Channels ◽  
Second Stage ◽  
Bound Rubber ◽  
Average Size

Abstract The present study leads to postulating the following mechanism for carbon black incorporation. During the first stage of incorporation, carbon black agglomerates become encapsulated by the polymer. At this stage, the interstices within these agglomerates are still filled with air, giving a very weak, crumbly composite. The rubber becomes forced into these interstices during the second stage of incorporation. As the rubber is being forced through the narrow channels between the aggregates, bound rubber is being formed. The immobilized layer of the polymer tends to reduce the effective cross section of the channels through which more rubber must pass before reaching the inner part of the agglomerates. Thus, as the activity of carbon black increases, e.g., higher bound rubber, the incorporation time increases. At a given carbon black activity, the effective thickness of the immobilized polymer layer would increase with increasing molecular weight of polymer, but be independent of the oil loading. This agrees with experimental observation that the incorporation time increases with molecular weight of the polymer, while oil loading has no effect other than that associated with the lowering of bound rubber content. The average size of channels through which rubber must pass depends also on the carbon black morphology. The size of these channels would be expected to increase with increasing structure of carbon black, and (to a lesser extent) with increasing particle size. These parameters have the expected influence on the incorporation time; since the incorporation time decreases with increasing DBPA value and decreasing tint.

Sorption of GR-S Type of Polymer on Carbon Black. III. Sorption by Commercial Blacks

1953 ◽  
Vol 26 (1) ◽  
pp. 102-114 ◽  
Author(s):  
I. M. Kolthoff ◽  
R. G. Gutmacher
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Intrinsic Viscosity ◽  
Benzene Solution ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Molecular Weights ◽  
Bound Rubber ◽  
Flow Through ◽  
Peculiar Behavior

Abstract The sorption capacities toward GR-S five commercial carbon blacks are in decreasing order: Spheron-6, Vulcan-1, Philblack-0, Sterling-105, Philblack-A. Apparently, the sorption is not related to surface area. The sorption on Vulcan-1 of GR-S from its solutions in seven different solvents or mixtures of solvents increases with decreasing solvent power for the rubber. The sorption curves of two “cold rubbers,” polymerized at −10 and +5° respectively, showed little difference from that of 50° GR-S. Previous heating of carbon black in nitrogen at 500 or 1100° increased the sorption by about 20 per cent over unheated carbon. Air-heating of carbon black at 425° did not cause a difference in the sorption from benzene solution, but produced an increase in the sorption of rubber from n-heptane solution. In the range 75% butadiene-25% styrene to 5% butadiene-95% styrene, there is practically no effect of the degree of unsaturation on the sorption. Polystyrene of high intrinsic viscosity exhibits a peculiar behavior with furnace blacks. Vulcan-1 sorbed microgel as well as the sol fraction from n-heptane solutions of GR-S containing microgel (conversion 74.7 and 81.5 per cent). There was no appreciable difference in the amount of sorption of rubber fractions having average molecular weights varying from 433,000 to 85,000. There is little change in the amount sorbed after two hours of shaking, but the intrinsic viscosity of the residual rubber decreases with time. The low molecular-weight rubber is sorbed more rapidly, but is slowly replaced by the more tightly sorbed high molecular weight fraction. Partial fractionation of a rubber sample can be achieved by allowing the rubber solution to flow through a column of weakly sorbing carbon black. A large portion of the sorbed rubber can be recovered from the column by washing it with a good solvent such as xylene. Bound rubber is produced by intimate mixing of equal parts of carbon black and rubber swollen in chloroform, when the mixture is dried in vacuum at 80° or at room temperature. Milling is not essential to get bound rubber.

Intrinsic viscoelasticity in thin high-molecular-weight polymer films

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
Xiaoyuan Sheng ◽  
Frédéric Wintzenrieth ◽  
Katherine R. Thomas ◽  
Ullrich Steiner
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polymer Films ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer

Structural studies of the capsular polysaccharide from Haemophilus pleuropneumoniae serotype 2

1987 ◽  
Vol 65 (5) ◽  
pp. 414-422 ◽  
Author(s):  
Eleonora Altman ◽  
Jean-Robert Brisson ◽  
Malcolm B. Perry
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Molecular Weight ◽  
Capsular Polysaccharide ◽  
Structural Studies ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Structure Formula ◽  
Nuclear Magnetic

The capsular polysaccharide of Haemophilus pleuropneumoniae serotype 2 (ATCC 27089) is composed of D-glucose (two parts), D-galactose (one part), glycerol (one part), and phosphate (one part). Hydrolysis, dephosphorylation, methylation, enzymic studies, and 1H and 13C nuclear magnetic resonance experiments showed that the polysaccharide is a high molecular weight polymer of a tetrasaccharide repeating units, linked by monophosphate diester and having the following structure:[Formula: see text]

Mixing of Carbon Black with Rubber. VI. Analysis of NR/SBR Blends

1988 ◽  
Vol 61 (4) ◽  
pp. 609-618 ◽  
Author(s):  
George R. Cotten ◽  
Lawrence J. Murphy
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
High Molecular Weight ◽  
Surface Area ◽  
Bound Rubber ◽  
Very High

Abstract The distribution of carbon black in NR/SBR blends was determined through the analysis of bound rubber. The NR/SBR blends were found to be very different from the previously studied SBR/BR compounds: these differences were assigned to mutual insolubility of the two polymers and a very high molecular weight of NR. In NR/SBR blends, it was found that changes in molecular weight of the polymer has no effect on the carbon black distribution in the blend. While the “activity” of carbon black did not affect the distribution, the loading of the black in NR decreased linearly with increasing surface area of the black. Approximately 35% of normal tread blacks (surface area 80–100 m2/g) was found in the NR phase. However, the bond between NR and carbon black is quite weak, and black continues to migrate into the SBR phase on prolonged mixing or during blending of NR and SBR masterbatches.

scholarly journals Antigen valence determines the binding of nominal antigen to cytolytic T cell clones.

1985 ◽  
Vol 162 (2) ◽  
pp. 768-773 ◽  
Author(s):  
R F Siliciano ◽  
R M Colello ◽  
A D Keegan ◽  
R Z Dintzis ◽  
H M Dintzis ◽  
...  
Keyword(s):  
Molecular Weight ◽  
T Cell ◽  
High Molecular Weight ◽  
Cytotoxic T Cell ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
T Cell Clones ◽  
Cell Clones ◽  
Nominal Antigen ◽  
Epitope Density

We have shown that cytotoxic T cell clones specific for the nominal antigen FL will bind high molecular weight (600,000 to 2,000,000) polyacrylamide and Ficoll polymers conjugated with 200-600 FL groups per molecule. Low molecular weight polymers (40,000) with the same epitope density did not give stable binding. A high molecular weight polymer with a lower epitope density also failed to bind. Taken together, these results suggest that a substantial degree of multivalence is a necessary factor in the stable binding of nominal antigen to T cell clones.

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