Electrostatic Properties of Rubber and GR-S

1945 ◽  
Vol 18 (2) ◽  
pp. 337-352
Author(s):  
R. S. Havenhill ◽  
H. C. O'Brien ◽  
J. J. Rankin
Keyword(s):  
Tensile Strength ◽  
Condensation Product ◽  
Electrostatic Charge ◽  
Contact Potential ◽  
Electrostatic Charges ◽  
Audio Amplifier ◽  
Synthetic Rubber ◽  
Current Voltage ◽  
High Zinc ◽  
Stationary Electrode

Abstract A new electrostatic modulator has been described for measuring the electrostatic charges on rubber, synthetic rubber, and various materials. In this apparatus the electrostatic lines of force established between the charged specimen and a stationary electrode plate connected to the grid of an audiofrequency amplifier are cut or modulated at audiofrequency by a small four-bladed, motor-driven fan. This produces in effect an alternating current voltage which can be readily amplified by the audio amplifier and quantitatively measured on a meter in the output circuit. This device, in conjunction with a mirror-surfaced metal plunger system for contacting the rubber samples, has been used to measure the contact potential of various rubber and GR-S compounds. Electrostatic contact potential data are shown for both rubber and GR-S compounds with and without organic and inorganic reinforcing agents, and these data bear out the formulation of an electrostatic contact potential theory of reinforcement in which the reinforcement of rubber and GR-S is explained on the basis of contact potentials and resultant electrostatic attractive forces which exist between the rubber and the reinforcing agents. By the application of this theory, organic materials which have a highly positive electrostatic charge, such as polymerized trimethyldihydroquinoline and Flectol-H (an acetone-aniline condensation product), have been found to increase the tensile strength of the pure-gum type of GR-S compounds as much as fivefold and nearly to double the tensile strength of high zinc oxide loaded GR-S compounds.

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 Влияние контактной разности потенциалов на вольт-амперные характеристики в сканирующей туннельной спектроскопии

2021 ◽  
Vol 91 (11) ◽  
pp. 1769
Author(s):  
М.В. Кузьмин ◽  
М.А. Митцев
Keyword(s):  
Contact Potential Difference ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Differential Conductivity ◽  
Contact Potential ◽  
Potential Barriers ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Work Functions ◽  
Conductivity Spectra

Using the energy diagrams of asymmetric potential barriers formed at the contact of two metals with different work functions, the influence of contact potential difference on the current-voltage characteristics and differential conductivity spectra measured by scanning tunneling spectroscopy is considered. It is shown that the obtained conclusions are in qualitative agreement with the experimental results for ytterbium nanofilms with the thickness of 16 monolayers (6.08 nm). However, they significantly differ quantitatively. The analysis of such diffrences is performed.

Modelling of Electrostatic Charge in Ultra-High Precision Diamond Turning of Contact Lens Polymer

2019 ◽  
Vol 298 ◽  
pp. 135-140
Author(s):  
Muhammad Mukhtar Liman ◽  
Khaled Abou El Hossein
Keyword(s):  
High Precision ◽  
Contact Lens ◽  
Feed Rate ◽  
Contact Lenses ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Electrostatic Charge ◽  
Diamond Turning ◽  
Depth Of Cut ◽  
Electrostatic Charges

The electrostatic charges encountered by a cutting tool when turning advanced contact lenses are important as they reflect the quality and condition of the tool, machine, fixture, and sometimes even the surface finished which is responsible for tool wear and poor surface quality. This study investigates the influence of cutting parameters namely cutting speed, feed rate and depth of cut on electrostatic charge (ESC) which play the leading role in determining the machine economics and quality of machining contact lens polymers. An electrostatic charge model based on response surface statistical method is developed for reliably predicting the values of static charging based on its relationship to cutting parameters in ultra-high precision diamond turning of contact lenses. It is clearly seen that all the model terms are significant with cutting speed having the highest degree of significance followed by feed rate and the interaction of speed and feed. However, depth of cut has the lowest degree of significance on the electrostatics charge.

The Synthesis of Isocyanate-Modified Novolak Resins for Use in Natural and Synthetic Rubber

1980 ◽  
Vol 53 (2) ◽  
pp. 239-244 ◽  
Author(s):  
N. D. Ghatge ◽  
B. M. Shinde
Keyword(s):  
Tensile Strength ◽  
Synthetic Rubber ◽  
Natural And Synthetic

Abstract Resin-C and Resin-B give higher values for tensile strength, modulus, and hardness than all other resins.

Elastomer-Resin Blends. Acrylonitrile Type Synthetic Rubber and Polyvinyl Chloride Resins

1949 ◽  
Vol 22 (3) ◽  
pp. 735-755
Author(s):  
D. W. Young ◽  
D. J. Buckley ◽  
R. G. Newberg ◽  
L. B. Turner
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Polyvinyl Chloride ◽  
Sodium Acetate ◽  
Blocking Temperature ◽  
Acrylonitrile Copolymer ◽  
Rubber Blends ◽  
Synthetic Rubber ◽  
Cure Time ◽  
Acrylonitrile Copolymers

Abstract 1. 1,3-Butadiene-acrylonitrile copolymers were mill-mixed with benzothiazoyl disulfide, sulfur, litharge, and vinyl resins, such as Vinylite (VYNW), and Saran and cured to compounds with good tensile strength, modulus, hardness, solvent resistance, and blocking temperature. 2. Results show that higher acrylonitrile type of copolymers give cured Vinylite-rubber blends with higher tensile strength, higher 100 per cent modulus, and greater ultimate elongation to break than low acrylonitrile copolymers. 3. The low temperature properties of the cured blends improve as the acrylonitrile content of the synthetic rubber is reduced. 4. An effective cure at 287° F is obtained in 15 to 30 minutes by using 2 parts of accelerator and 2 parts of sulfur per hundred parts of 1,3-butadieneacrylonitrile type copolymer-Vinylite blends. Added amounts of sulfur, and accelerator did not improve the properties or decrease the cure time at 287° F. 5. Some of the cured blends studied are free of tackiness at temperatures as high as 230° F. 6. Some stabilizers for vinyls tested as well as sodium acetate can be used to activate sulfur cures in 1,3-butadiene-acrylonitrile copolymer-Vinylite blends to formulate light-colored transparent products.

Heat Generation in Flexed Rubber

1944 ◽  
Vol 17 (1) ◽  
pp. 76-91 ◽  
Author(s):  
S. D. Gehman ◽  
P. J. Jones ◽  
D. E. Woodford
Keyword(s):  
Tensile Strength ◽  
Heat Generation ◽  
High Speed ◽  
Synthetic Rubber ◽  
Tear Resistance

Abstract The problem of heat generation in tires assumes new importance with the advent of synthetic rubber and the increased use of reclaimed rubber. Even if reduced speeds may prevent heat blowouts, higher temperatures mean that both fabric and rubber are operating under unfavorable conditions. Synthetic rubber, in particular, is then working at reduced tensile strength and tear resistance. It is more susceptible to heat embrittlement, cuts, and abrasion. A number of flexometers for rubber testing have been described, and some of these instruments have been widely used. The flexometer described here is characterized by simplicity of construction, high speed, and convenience of operation.

scholarly journals Effect of method of measuring on size of electrostatic charge and grinding efficiency of a pinewood

Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 918-921
Author(s):  
Stanisław Płonka ◽  
Piotr Zyzak
Keyword(s):  
Constant Pressure ◽  
Electrostatic Charge ◽  
General Purpose ◽  
Time Function ◽  
Electrostatic Charges ◽  
Grinding Speed ◽  
Grinding Efficiency

In the paper is presented a station to measurement of electrostatic charge generated during grinding operation of pinewood. Size of the charge was determined in course of measurement of voltage in function of time. It has been investigated an effect of two types of abrasive papers: general-purpose paper of PS 18E brand and antistatic one of PS 15F brand on value of the voltage during grinding operation, and weight efficiency of a specimens made from the pinewood, at constant pressure equal to p = 4,54 kPa and variable grinding speed vc in range from 12,1 to 24,2 m/s. It was found that the method of measuring electrostatic charges by recording voltage in the time function U = f(t) has a significant effect primarily on the sign of arising charges and the repeatability of the obtained voltage waveforms during grinding.

scholarly journals Parametric Optimization of Metal Inert Gas Welding for Hot Die Steel by using Taguchi Approach

2018 ◽  
Vol 15 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Vijander Kumar ◽  
Navneet Goyal
Keyword(s):  
Tensile Strength ◽  
Weld Bead ◽  
Bead Geometry ◽  
Weld Penetration ◽  
Weld Bead Geometry ◽  
Maximum Tensile Strength ◽  
Current Voltage ◽  
Result Show ◽  
Metal Inert Gas Welding ◽  
Different Levels

In present experimental study an attempt has been made to investigate the effect of three machine input parameters namely current,voltage and nozzle to plate distance (NPD) on tensile strength of weld bead and weld penetration. Three different levels (current 180, 190, 200 in ampere. Voltage 21, 24, 27 in volt and NPD 12, 16, 20 in mm) have been considered in order to evaluate the effect of these parameters on tensile strength and penetration of weld bead. Taguchi method has been employed to abate the number of experiments and analyze the effect of various parameters. Orthogonal array L9 was used for data optimization. On the basis of experimental data, the mathematical technique has been developed by using analysis of variance. Results were obtained from each parameter at different levels for tensile strength and weld bead geometry. Based on these results different parameters were identified for maximum tensile strength and maximum weld penetration. Result show that maximum tensile strength was 390.8 Mpa at 200 ampere current, 27 volt and 16 mm NPD where as maximum weld penetration was 3.20 mm at 200 ampere current, 24 volt and 12 mm NPD

Optimisation of Tensile Strength and Weight Loss via Taguchi and Response Surface Method for Natural Rubber Latex Film Consisting Cassava Peel as a Bio-Based Filler

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Mahiratul Husna Mustaffar ◽  
◽  
Aliff Hisyam A. Razak ◽  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Synthetic Rubber ◽  
Surface Method ◽  
Prepared Composite ◽  
Cassava Peel

Disposal latex and synthetic rubber gloves is troublesome such that disposal via incineration and land fill may release poisonous gasses and contaminate soil and water, respectively. As solution to latex and synthetic rubber, biodegradable glove is extensively studied. A bio-based filler is extracted from food waste and blended into natural rubber latex (NRL) as a composite NRL. The effect of biodegradability of composite NRL was studied by varying the loading of bio-based filler in a form of starch dispersion and blended into NRL mixture. Herein some amount of starch can be extracted from cassava peel to be incorporated in NRL for a sustainable and yet biodegradable glove. Previous work on incorporation of cassava-peel filler in NRL has shown a biodegradability without compromising the pristine strength of NRL film at 50% loading starch. In this project, tensile strength and weight loss of prepared composite NRL films were optimised via Taguchi and Response Surface Method (RSM) by means of Design Expert software by varying starch/filler loading, curing temperature and curing drying duration. Due to inadequate data, the optimisation from that previous prepared composite NRL was compared with similar work which utilising NRL and bio-based filler. For Pulungan (2020) study, it can be concluded that the tensile strength of cassava peel starch biodegradable film has the best condition at 50°C to 60°C at approximately 5.5 hours. Elongation optimum conditions shows contrast value of temperature and time. Meanwhile, for Wendy (2020) study, it shows the best percentage loading of cassava-peel starch is at 20% to achieve high stress and strain at break. The optimised mechanical properties via Taguchi and RSM are rather different and hence validation on mechanical properties at above mentioned conditions need to be performed experimentally.

Conception of the Kelvin Method on the Basis of a Mechanic-Electrical Transformation

2018 ◽  
Vol 63 (3) ◽  
pp. 269
Author(s):  
Yu. S. Zharkikh ◽  
S. V. Lysochenko
Keyword(s):  
Mechanical Energy ◽  
Contact Potential Difference ◽  
Electrical Potential ◽  
Potential Difference ◽  
Atomic Scale ◽  
Measured Signal ◽  
Electrical Potential Difference ◽  
Kelvin Probe ◽  
Contact Potential ◽  
Electrostatic Charges

The Kelvin method was based on the concept of the dynamic capacitor recharging by a contact potential difference. The present paper draws attention to the fact that the contact potential difference is not the same physical agent as the electrical potential difference due to the electromotive force. It cannot act as an active electrical voltage and, accordingly, cause the flow of an electric recharging current. The real reason for the appearance of a measured signal is the transformation of the electrode movement mechanical energy into the electric current energy. The current is generated due to periodic changes in the screening conditions of electrostatic charges above the investigated surface. Investigations are made of the method sensitivity to the amount of charges on the sample surface. It is shown that the measurement results are interpreted without invoking the ideas of the work function. Therefore, the method can besuccessfully used in studies of organic and biological materials and electrolytes. The proposed mechanism is applicable in both the investigations of macroscopic distributions of the surfacecharge and the atomic scale in the Kelvin probe force microscopy.

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