Surface Chemistry of Carbon Black. Effect on Vulcanization of Rubber

1935 ◽  
Vol 8 (3) ◽  
pp. 483-498
Author(s):  
Frank K. Schoenfeld
Keyword(s):  
Carbon Black ◽  
Organic Acids ◽  
Surface Chemistry ◽  
Organic Acid ◽  
Experimental Evidence ◽  
Acid Complex ◽  
Adsorption Theory ◽  
Rubber Compounds

Abstract In an attempt to develop a theory for the retardation of the rate of cure of rubber stocks by carbon black the adsorption theory is critically reviewed. Experimental evidence is presented that is not readily explainable on the basis of this theory. It is shown that the retarding action of gas black is analogous to the action of organic acid retarders of cure. The mechanism of this action is unknown. Gas black activatedly adsorbs oxygen to form an acid complex that retards the cure of rubber compounds. Organic acids have been obtained from commercial blacks by washing with alkalies.

Oxidation of Unvulcanized Cold Rubber Influence of Adsorption by Carbon Black

1952 ◽  
Vol 25 (3) ◽  
pp. 557-572
Author(s):  
C. W. Sweitzer ◽  
Francis Lyon
Keyword(s):  
Carbon Black ◽  
Surface Chemistry ◽  
Carbon Films ◽  
Cross Linking ◽  
Additional Information ◽  
Rubber Compounds ◽  
Repressive Effect ◽  
Solvent Systems ◽  
Dilute System

Abstract Previous investigations have shown a large difference between the amount of rubber insolubilized by carbon black in dilute solvent systems and in standard mill mixes. The purpose of this study, after reconciling these extremes, was to evaluate the role of adsorption in the insolubilization of rubber in mill-mixed compounds. An adsorption test was employed which eliminated the solvent effect of the dilute system and the mastication effect in mill mixing. Results showed that carbon black, depending on the temperature and atmosphere conditions imposed on the rubber carbon films, represses the scission, cross-linking, and gelation reactions of GR-S X-478. This repressive effect is ascribed to the adsorption and inactivation by the carbon black of the oxidized intermediates through which these various reactions proceed. The magnitude of this effect was found to vary with the type, loading, and surface chemistry of the carbon. This approach not only offers promise as a means for predicting the behavior of carbon black in rubber compounds, but also, because of its applicability to the study of all rubber-carbon systems, offers possibilities of providing additional information on the mechanism of the carbon-rubber bond.

Thermal aging of carbon black filled rubber compounds. I. Experimental evidence for bridging flocculation

Polymer ◽  
2003 ◽  
Vol 44 (23) ◽  
pp. 7229-7240 ◽  
Author(s):  
Gustavo A. Schwartz ◽  
Silvina Cerveny ◽  
Ángel J. Marzocca ◽  
Michel Gerspacher ◽  
Leszek Nikiel
Keyword(s):  
Carbon Black ◽  
Experimental Evidence ◽  
Thermal Aging ◽  
Bridging Flocculation ◽  
Filled Rubber ◽  
Rubber Compounds

Partial replacement of carbon black by nanoclay in butyl rubber compounds for tubeless tires

2017 ◽  
Vol 59 (11-12) ◽  
pp. 1054-1060 ◽  
Author(s):  
Mohan Kumar Harikrishna Kumar ◽  
Subramaniam Shankar ◽  
Rathanasamy Rajasekar ◽  
Pal Samir Kumar ◽  
Palaniappan Sathish Kumar
Keyword(s):  
Carbon Black ◽  
Butyl Rubber ◽  
Partial Replacement ◽  
Rubber Compounds

scholarly journals PSVIII-16 The effects of adding two organic acid blends with or without high levels of zinc or copper, on post-weaning pig performance

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 209-210
Author(s):  
Casey L Bradley ◽  
Jon Bergstrom ◽  
Jeremiah Nemechek ◽  
J D Hahn
Keyword(s):  
Phosphoric Acid ◽  
Benzoic Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Factorial Design ◽  
Sodium Butyrate ◽  
Weaned Pigs ◽  
Weaning Pig ◽  
Pig Performance ◽  
Dietary Treatments

Abstract A subset of 720 weaned pigs (6.44 ± 0.1 kg, PIC genetics, approximately 21-d of age) were used in a 42-d trial with a 2x3 factorial design evaluating the effects of adding organic acid (OA) blends [factor 1 = no organic acid (NO), Acid Pak 1 (AP1), Acid Pak 2 (AP2)] to diets with or without higher levels of Zn or Cu [factor 2 = +/-PZC] on pig performance. Pigs were allotted 10 pigs/pen to 12 weight blocks and randomly assigned the six dietary treatments. The +PZC diets contained 3000 ppm Zn (d 0-7), 2000 ppm Zn (d 8-21), and 250 ppm Cu (d 21-42) and -PZC diets contained 95 ppm Zn and 20 ppm Cu (d 0-42). The AP1 and AP2 diets used 0.9% of 2 acid premixes (d 0-21), and 0.45% of the premixes (day 22-42). AP1 provided 0.5% benzoic acid, 0.07% sodium butyrate, and 0.025% phosphoric acid (day 0-21) and half those levels (day 22-42). AP2 included the same acids as AP1 but at half the rate and combined with 7 other organic acids and carvacrol. From d 0-21, ADG, ADFI, and G:F were improved (P< 0.01) by +PZC compared to -PZC and by AP1 or AP2 compared to NO (P< 0.02). Overall (d 0-42), ADG and G:F were improved (P< 0.01) by +PZC compared to -PZC and by AP1 or AP2 compared to NO (P< .010). Data from this trial indicate that performance was improved by the addition of both OA and PZC. However, pigs fed OA and -PZC performed similarly to those fed NO and +PZC in the post-weaning period. In summary, regardless of the acid combination, organic acid supplementation has the potential to improve growth performance in weaned pigs.

The Xylem Sap of Maize Roots: Its Collection, Composition and Formation

1988 ◽  
Vol 15 (4) ◽  
pp. 557 ◽  
Author(s):  
MJ Canny ◽  
ME Mccully
Keyword(s):  
Amino Acids ◽  
Organic Acids ◽  
Organic Acid ◽  
Aspartic Acid ◽  
Xylem Sap ◽  
Great Variability ◽  
Reduced Pressure ◽  
Transpiration Stream ◽  
Maize Roots ◽  
Total Amino Acids

Three methods of sampling xylem sap of maize roots were compared: sap bleeding from the stem cut just above the ground; sap bleeding from the cut tops of roots still undisturbed in the ground; and sap aspirated from excavated roots under reduced pressure. The bleeding saps were often unobtainable. When their composition was measured with time from cutting, the concentrations of the major solutes approximately doubled in 2 h. Aspirated sap was chosen as the most reliable sample of root xylem contents. Solute concentrations of the saps showed great variability between individual roots for all solutes, but on average the concentrations found (in �mol g-1 sap) were: total amino acids, 1.8; nitrate, 1.8; sugars (mainly sucrose), 5.4; total organic acids, 18.3. Individual amino acids also varied greatly between roots. Glutamine, aspartic acid and serine were generally most abundant. The principal organic acid found was malic, approximately 8 �mol g-1. From these analyses the ratios of carbon in the fractions (sugars : amino acids : organic acids) = (44 : 6 : 50). 14Carbon pulse fed to a leaf appeared in the root sap within 30 min, rose to a peak at 4-6 h, and declined slowly over a week. During all this time the neutral, cation and anion fractions were sensibly constant in the proportions 86 : 10 : 4. The 14C therefore did not move towards the equilibrium of 12C-compounds in the sap. It is argued that the results do not support a hypothesis of formation of amino carbon from recent assimilate and reduced nitrate in the roots and an export of this to the shoot in the transpiration stream.

scholarly journals Characterization of Aerosol Composition, Aerosol Acidity and Organic Acid Partitioning at an Agriculture-Intensive Rural Southeastern U.S. Site

2018 ◽  
Author(s):  
Theodora Nah ◽  
Hongyu Guo ◽  
Amy P. Sullivan ◽  
Yunle Chen ◽  
David J. Tanner ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Organic Acids ◽  
Organic Acid ◽  
Organic Aerosol ◽  
Water Soluble ◽  
Molar Concentration ◽  
Particle Phase ◽  
Aerosol Composition ◽  
Phase Water ◽  
Acetic Acids

Abstract. The implementation of stringent emission regulations has resulted in the decline of anthropogenic pollutants including sulfur dioxide (SO2), nitrogen oxides (NOx) and carbon monoxide (CO). In contrast, ammonia (NH3) emissions are largely unregulated, with emissions projected to increase in the future. We present real-time aerosol and gas measurements from a field study conducted in an agricultural-intensive region in the southeastern U.S. during the fall of 2016 to investigate how NH3 affects particle acidity and SOA formation via the gas-particle partitioning of semi-volatile organic acids. Particle water and pH were determined using the ISORROPIA-II thermodynamic model and validated by comparing predicted inorganic HNO3-NO3− and NH3-NH4+ gas-particle partitioning ratios with measured values. Our results showed that despite the high NH3 concentrations (study average 8.1 ± 5.2 ppb), PM1 were highly acidic with pH values ranging from 0.9 to 3.8, and a study-averaged pH of 2.2 ± 0.6. PM1 pH varied by approximately 1.4 units diurnally. Formic and acetic acids were the most abundant gas-phase organic acids, and oxalate was the most abundant particle-phase water-soluble organic acid anion. Measured particle-phase water-soluble organic acids were on average 6 % of the total non-refractory PM1 organic aerosol mass. The measured molar fraction of oxalic acid in the particle phase (i.e., particle-phase oxalic acid molar concentration divided by the total oxalic acid molar concentration) ranged between 47 and 90 % for PM1 pH 1.2 to 3.4. The measured oxalic acid gas-particle partitioning ratios were in good agreement with their corresponding thermodynamic predictions, calculated based on oxalic acid’s physicochemical properties, ambient temperature, particle water and pH. In contrast, gas-particle partitioning of formic and acetic acids were not well predicted for reasons currently unknown. For this study, higher NH3 concentrations relative to what has been measured in the region in previous studies had minor effects on PM1 organic acids and their influence on the overall organic aerosol and PM1 mass concentrations.

scholarly journals Insights into the Payne Effect of Carbon Black Filled Styrene-butadiene Rubber Compounds

2020 ◽  
Vol 39 (1) ◽  
pp. 81-90
Author(s):  
An Zhao ◽  
Xuan-Yu Shi ◽  
Shi-Hao Sun ◽  
Hai-Mo Zhang ◽  
Min Zuo ◽  
...  
Keyword(s):  
Carbon Black ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Payne Effect ◽  
Rubber Compounds ◽  
Styrene Butadiene

Ultrasonic Measurements with Rubber Compounds during Extrusion

1979 ◽  
Vol 52 (2) ◽  
pp. 294-303 ◽  
Author(s):  
R. Caspary ◽  
P. Kretschmer
Keyword(s):  
Carbon Black ◽  
Sound Velocity ◽  
Specific Volume ◽  
Carbon Black Content ◽  
Rubber Compounds ◽  
Ultrasonic Measurements ◽  
Temperature And Pressure ◽  
Reciprocal Value

Abstract The dependence of the Index of Elasticity, E, the reciprocal value of sound velocity, on temperature and pressure is related to specific volume and compressibility of rubbers. The sensitivity of E towards changes of temperature and pressure was calculated, indicating a new versatile possibility for the control of rubber extruders. To confirm this, extruder experiments were carried out with an SHR compound, of which a working diagram was established showing the complete behavior of E=f(p,T). The effect of compound composition, especially of plasticizer and carbon black content, was examined. Viscosity in the extruder primarily determines changes in E. The method was shown to be applicable up to a die diameter of at least 200 mm. The method may also be applied to follow degradation of rubber compounds during mastication.

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.

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