Pigment Contact Potentials and Reinforcement

1963 ◽  
Vol 36 (1) ◽  
pp. 176-193
Author(s):  
R. S. Havenhill ◽  
L. E. Carlson
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Calcium Carbonate ◽  
Contact Potential ◽  
Zinc Oxides ◽  
Polybutadiene Rubber ◽  
New Apparatus ◽  
Mohs Hardness ◽  
Processing Properties ◽  
Cut Surface

Abstract 1. A new apparatus has been described for measuring the contact potential of powdered reinforcing pigments. 2. With this apparatus, contact potentials on MPC and FT blacks, fine and coarse particle size zinc oxides, whiting, and barytes show correlation with their reinforcing properties in natural rubber and cis-1 ,4-polybutadiene rubber. 3. Contact potentials of Hi-Sil, Suprex clay, coated zinc oxides and coated calcium carbonate pigments showed no correlation with their reinforcing properties in rubber. 4. Contact potentials on the minerals, diamond, quartz, zinc oxide, calcite and barite correlated with the reinforcing properties of their pigment counterparts. 5. Contact potentials of the minerals also correlated with Mohs hardness. 6. Contact potentials on coated zinc oxide pigments correlated with their improved processing properties in rubber. 7. A new apparatus has been described for measuring the contact potentials of cured stocks in which cut surfaces, rather than molded surfaces, are used. Greater accuracy is possible due to the elimination of surface bloom and other surface contamination. 8. Contact potentials measured on the cut surface of cis-1,4-polybutadiene stocks containing various pigments showed good correlation with their reinforcing properties, thus confirming, with this new rubber, the Electrostatic Contact Potential Theory of Reinforcement.

Processing Characteristics of Rubber Compounds- - -. Effect of Pigment Particle Size and Surface

1938 ◽  
Vol 11 (3) ◽  
pp. 585-590
Author(s):  
A. H. Nellen ◽  
C. E. Barnett
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Zinc Oxide ◽  
Abrasion Resistance ◽  
Pigment Particle ◽  
Rubber Compound ◽  
Zinc Oxides ◽  
Truck Tire ◽  
Rubber Compounds ◽  
Processing Properties

Abstract A STUDY of the processing properties imparted by any pigment to a rubber compound is important in determining the most effective and economical type of pigment for a particular purpose. For example, in a truck tire carcass compound where zinc oxide may be the main pigment, in order to obtain the maximum quality this zinc oxide should be of the type which will give a soft uncured stock and free-flowing qualities so that the cords in the carcass may be thoroughly impregnated during the calendering and curing processes. Also, in a tread compound where channel black is the main pigment, that type of black which will allow faster incorporation into the rubber, faster extrusion, and better flowing qualities will result in manufacturing economies. In the case of both the zinc oxides and the carbon blacks it is essential that these desirable processing characteristics be obtained without losses in other properties, such as rate of cure, tensile strength, and abrasion resistance.

Rheological Behavior of Highly Filled EPDM Compounds with Calcium Carbonate, Carbon Black, Silica and Zinc Oxide

1996 ◽  
Vol 69 (4) ◽  
pp. 628-636 ◽  
Author(s):  
Li Li Li ◽  
James L. White
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Calcium Carbonate ◽  
Shear Rate ◽  
Carbon Black ◽  
Shear Viscosity ◽  
Volume Fraction ◽  
Carbonate Carbon ◽  
Yield Value ◽  
Yield Values

Abstract The shear viscosity, creep and constant shear rate transients have been measured for 0.20 volume fraction compounds of an EPDM with calcium carbonate, carbon black, silica and zinc oxide of similar particle size at 100°C. Measurements have been made in a creep sandwich instrument, pressurized rotational rheometer and a capillary rheometer and cover nine decades of shear rate. All of the compounds exhibit enhanced viscosities and yield values; i.e. there are stresses below which there is no flow. The greatest yield values and increased viscosities are with the compounds with calcium carbonate and zinc oxide. More extensive studies were made with the EPDM-calcium carbonate system, where it was shown that, increasing particle size reduces shear viscosity and yield values. Further, surface treating calcium carbonate with stearic acid signifcantly reduces the shear viscosity and yield value of the corresponding EPDM compound.

Refractometer Studies on Rubber-Pigment Mixtures

1940 ◽  
Vol 13 (3) ◽  
pp. 649-654 ◽  
Author(s):  
H. C. Jones
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Refractive Index ◽  
Fine Particle ◽  
Transmitted Light ◽  
Published Data ◽  
Rubber Mixture ◽  
Zinc Oxides ◽  
Fine Particle Size ◽  
Free Sulfur

Abstract Several years ago, McPherson and Cummings published data on the refractive index of rubber and of rubber-pigment mixtures. They found no difference in the refractive index of rubber from various sources. The degree of mastication did not appreciably change the refractive index. Sulfur in combination with rubber altered the refractive index relatively more than free sulfur in rubber. With the exception of zinc oxide, the pigments and fillers they examined did not affect the refractive index. In the case of zinc oxide, there was a significant increase in refractive index and the fine particle size oxide (Kadox) developed a higher value than the coarser oxide (XX Red). They suggested that zinc oxide probably reacts with the nonrubber components to form salts which dissolve and change the refractive index. This laboratory found that, for a series of various particle size zinc oxides in rubber, the increase in refractive index was inversely proportional to the particle size of the oxides; that is, a fine particle size zinc oxide increased the refractive index somewhat more than a coarse oxide. It was also observed that the refractive index of zinc oxide-rubber mixtures increased proportionally with each addition of zinc oxide until the opacity of the zinc oxide-rubber mixture became too great (over 6 per cent) to allow measurement by transmitted light.

“Colloidal” Zinc Oxide

1937 ◽  
Vol 10 (2) ◽  
pp. 309-311
Author(s):  
H. A. Curran ◽  
T. R. Dawson
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Manufacturing Industry ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Average Particle ◽  
Average Particle Diameter ◽  
Zinc Oxides ◽  
Two Samples ◽  
Good Grade

Abstract Some ten years ago, when so-called “colloidal” zinc oxides were being introduced to the rubber manufacturing industry, two samples were investigated to determine their behavior in rubber compared with ordinary good quality zinc oxide used in rubber. According to accounts published at the time, “colloidal” zinc oxide possesses an average particle size just within the limit of resolution of high-power microscopes, and an average particle diameter of 0.15 micron. In rubber it has been claimed to impart superior reinforcement, higher tensile strength, greater resistance to abrasion, and enhanced activation of organic accelerators. In the following report, samples A and B represent two samples of the same grade of “colloidal” zinc oxide, and C a good grade of regular zinc oxide.

Electrostatic and Tensile Properties of Rubber and GR-S at Elevated Temperatures

1946 ◽  
Vol 19 (2) ◽  
pp. 428-443
Author(s):  
R. S. Havenhill ◽  
H. C. O'Brien ◽  
J. J. Rankin
Keyword(s):  
Tensile Strength ◽  
Zinc Oxide ◽  
Test Specimen ◽  
Elevated Temperatures ◽  
Electrostatic Charge ◽  
Inclined Plane ◽  
Contact Potential ◽  
New Apparatus ◽  
Highly Loaded ◽  
Positive Materials

Abstract A new apparatus has been described for measuring contact potentials of rubber and GR-S compounds at elevated temperatures. In this apparatus, the electrostatic charge, acquired by rolling a steel ball down the surface of a rubber test-specimen on a heated inclined plane, is measured when the ball drops into the cup of an electrostatic modulator. This potential, although not the actual contact potential, is nevertheless, proportional to it. With this apparatus, the contact potential of GR-S at elevated temperatures was found to increase much more (become more negative) than that of rubber. The release of electrons (increase in negative contact-potential) and consequent disruption of electrostatic attractive forces within the material at elevated temperature probably partly accounts for the much greater decrease in tensile strength of GR-S over rubber, and is further confirmation of the electrostatic contact potential theory of reinforcement. By the further application of this theory, highly positive materials, such as certain proteins, finely divided silica, and sodium silicate, which retain their positive charges at elevated temperatures and make the stocks more positive, have been found to more than double the hot tensile strengths of compounds made from GR-S latex and highly loaded with zinc oxide.

scholarly journals ZnWO4 Nanoparticle Scintillators for High Resolution X-ray Imaging

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1721
Author(s):  
Heon Yong Jeong ◽  
Hyung San Lim ◽  
Ju Hyuk Lee ◽  
Jun Heo ◽  
Hyun Nam Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
High Resolution ◽  
Tungsten Oxide ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
Average Size ◽  
And Tungsten

The effect of scintillator particle size on high-resolution X-ray imaging was studied using zinc tungstate (ZnWO4) particles. The ZnWO4 particles were fabricated through a solid-state reaction between zinc oxide and tungsten oxide at various temperatures, producing particles with average sizes of 176.4 nm, 626.7 nm, and 2.127 μm; the zinc oxide and tungsten oxide were created using anodization. The spatial resolutions of high-resolution X-ray images, obtained from utilizing the fabricated particles, were determined: particles with the average size of 176.4 nm produced the highest spatial resolution. The results demonstrate that high spatial resolution can be obtained from ZnWO4 nanoparticle scintillators that minimize optical diffusion by having a particle size that is smaller than the emission wavelength.

Particle Size, Structure and Powdering Process of Calcium Carbonate Nanoparticles Filled Powdered Styrene-Butadiene Rubber

2011 ◽  
Vol 415-417 ◽  
pp. 237-242
Author(s):  
Zhou Da Zhang ◽  
Xue Mei Chen ◽  
Guo Liang Qu
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Size Structure ◽  
Average Diameter ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Particle Structure ◽  
Styrene Butadiene ◽  
New Particles

Calcium carbonate nanoparticles (nano-CaCO3) filled powdered styrene-butadiene rubber (P(SBR/CaCO3) was prepared by adding nano-CaCO3 particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO3) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO3 particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO3) by coagulating “new particles”. The SEM results also shown that the nano-CaCO3 and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO3) particles and nano-CaCO3 dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.

Sign in / Sign up

Export Citation Format

Share Document