Dynamic Properties Of Rubber Research Articles

Dynamic properties of butadiene styrene rubbers with layered silicates

In our study, modification of SBR-1705 butadiene styrene latex using a variety of bentonite clay variants was carried out Among them were domestic sodium bentonite, domestic bentonite pretreated with surfactants (surfactants), as well as organoclays based on foreign layered silicates and also treated with surfactants at the coagulation stage with subsequent rubber release. Further, within the framework of our study, we carried out a detailed comparative study of physical and mechanical properties of rubbers produced using modified butadiene-styrene rubbers. We considered rubbers containing different variants of bentonite, including both domestic origin and imported bentonite. The dynamic properties of these rubbers, including elastic modulus and mechanical loss angle tangent, were analyzed using dynamic thermomechanical analysis (DTMA). The study found that the rubber samples containing PT clay and Cloisite 30B showed a 20% reduction in mechanical loss tangent within the operating temperature range. This indicates an improvement in the mechanical properties of the rubber under a variety of operating conditions. In addition, rubber samples containing imported layered silicates and treated with surfactants exhibited increased strength both before and after thermo-oxidative aging at 150°C. These results emphasize the importance of silicate and surfactant composition selection in developing rubbers with improved mechanical properties and durability. The findings of this study have important implications for industry and academia, emphasizing the role of proper bentonite selection and processing in creating rubbers with optimal performance for a variety of applications

Investigation of the Dynamic Properties of Seawater-Resistant Rubber

The influence of rubbers, trans-polynorbornene, polyisobutylene P-200 and sevilene on vulcanization characteristics, physical-mechanical and dynamic properties of rubber used for the manufacture of products in contact with sea water has been investigated. It has been established that the developed rubber with a sulfur vulcanizing system based on rubbers SKMS-30ARK, SKN-4065 and BK-1675 with additives of trans-polynorbornene and sevilene 11808-340 has improved physical and mechanical characteristics, resistance to sea water and increased dynamic properties

STUDYING OF EFFICIENT AND SEMI-EFFICIENT CURING SYSTEMS INFLUENCE ON DYNAMICAL PROPERTY AND OZONRESISTANT OF RUBBER

There was showed dependence of the storage modulus and the loss modulus on shear deformation in torsion. For the first time type of curing system influence on Payne and Mullins effect is investigated. The Cole-Cole plots exhibit the contribution of the cross-linking system effect in the dynamic properties of rubber. There was increase of ozone resistance of rubber based on efficient curing system in condition general stress to critical stress is showed.

RESEARCH OF OPERATIONAL AND DYNAMIC PROPERTIES OF RUBBER FOR PRODUCTS WORKING IN SEA WATER

The article studies the effect of trans-polynorbornene, general and special-purpose rubbers and fillers on the vulcanization characteristics of a rubber mixture, physical, mechanical, operational and dynamic properties of vulcanizates based on butadiene methylstyrene caoutchouc. The investigated model rubber mixture included SKMS-30ARK rubber, sulfur, 2,2'-dibenzthiazole disulfide, guanide F, zinc white, stearic acid, phenyl-2-naphthalamine, N-isopropyl-N'-phenyl-para-phenylenediamine, carbon blacks of grades P 514 and N 220, shungite powder and other ingredients. The rubber mixture was produced on laboratory rolls LB 320 160/160. The first (basic) version of the rubber mixture contained industrial oil I-12A as a softener. The second version of the mixture contained a modifying additive based on trans-polynorbornene and industrial oil I-12A. The third, fourth and fifth versions were prepared on the basis of a combination of rubbers SKMS-30ARK, SKN-4065 and BK-1675, including a modifying additive, as well as polyisobutylene P-118 and sevilen 11808-340. The vulcanization characteristics of the rubber mixture were studied on an MDR 3000 Basic rheometer at 150 °C for 30 min. To determine the physical and mechanical properties of rubber, standard samples of all variants of the rubber mixture were vulcanized at a temperature of 143 °C for 30 min in a vulcanization press of the P-V-100-3RT-2-PCD type. Studies of the physical, mechanical, operational and dynamic properties of rubber were carried out in accordance with the existing standards for the rubber industry. It is shown that vulcanizates containing a modifying additive have lower values of conventional tensile strength, hardness and tear resistance compared to vulcanizate of the base version of the rubber mixture and are characterized by increased dynamic and performance properties. Rubber containing a combination of butadiene-nitrile, butadiene-methylstyrene caoutchoucs and butyl caoutchouc, 10.0 mass parts sevilen 11808-340, 20.0 mass parts of trans-polynorbornene composed of in the modifying additive and 55.0 mass parts of carbon black P 324, possesses improved physical, mechanical and dynamic properties, as well as high resistance in sea water.

Effect of carbon black/nanoclay hybrid filler on the dynamic properties of natural rubber vulcanizates

AbstractIn this study, natural rubber (NR) nanocomposites based on carbon black (CB) and two poly(ethylene glycol) (PEG)‐modified clay hybrid filler were fabricated. The morphology and mechanical properties were studied. The dynamic properties of NR vulcanizates were investigated over a range of strain amplitude at two temperatures. It was found that NR with hybrid filler exhibits superior mechanical properties over that with CB as single phase filler. The hybrid filler causes a significant alteration in the dynamic properties of rubber. The Payne effect becomes more pronounced in rubber with modified clay. A decrease in loss factor (tanδ) was observed for rubber with hybrid filler also. The results revealed that the inclusion of nanoclay (NC) could induce a stronger and more developed filler network. Because of the anisotropy of the nanolayers, NC would depress the reconstruction of filler network, or lower the reformation rates when broken down under deformation, giving rise to lower tanδ value at broad temperature range as well as strain amplitude. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

고무부품의 동특성 예측

Although rubber components are extensively used in mechanic parts. There are still a lot of difficulties in designing the rubber components applied in complex shapes and preloaded states because of the complicated material properties. One of the most important parameters for more detailed and accurate mechanical analysis during the development stages is the dynamic characteristics of the rubber components. It is well known that the dynamic properties of rubber are dependent on frequency as well as static preload. Consequently, a large number of experiments have to be conducted to identify the dynamic stiffness of a rubber bush considering the various applied conditions. In this paper, an efficient experimental method is suggested, which estimates the dynamic stiffness of a rubber bush using rubber material test and static stiffness of the bush. This method is capable of predicting the dynamic stiffness of a rubber bush under various load conditions from minimized test data.

A Comparative Investigation of Surface Modification of Carbon Black and Silica by Plasma Polymerization

Abstract Carbon black and silica are widely used active fillers in the rubber industry to improve the physical and dynamic properties of rubbers. The surface energy difference between rubbers and these active fillers is large, which has a negative influence on the stability of their dispersion in the rubber matrix and on the distribution in blends of different rubbers. Reduction of the surface energy of carbon black and silica is aimed for by modifying their surfaces. Plasma polymerization is utilized to modify the surface of carbon black and silica by depositing a thin film over its surface. The modified fillers are characterized using thermogravimetric analysis (TGA), x-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (ToF-SIMS). The studies show that carbon black and silica behave differently towards surface modification by plasma polymerization. The difference in behavior of carbon black and silica is related to the availability of active sites on their surface during exposure to the plasma atmosphere. In this paper the mechanistic aspects of surface modification by plasma polymerization are also discussed.

Comparison of Test Specimens for Characterizing the Dynamic Properties of Rubber

Dynamic material properties inferred via experiment can be strongly influenced by the choice of test specimen geometry unless care is taken to ensure that mechanical fields (stress, strain, etc.) within the specimen adequately reflect the ideal homogeneous deformation state. In this work, finite element models of simple shear, cylindrical compression, simple tension, and bi-conical shear test specimens were analyzed in order to quantify the relative conformity of each specimen to its corresponding ideal. Three metrics of conformity were evaluated, based respectively on the distributions of stress, strain, and strain energy density. The results show that a simple shear specimen provides superior conformity. Other factors involved in the selection of test specimen geometry are also discussed. Such factors include relative linearity and symmetry of measured stress–strain data, grip slip, and heat build up.

Handbook of Mechanical Damping and Acoustical Dynamic Properties of Rubbers and Elastomers

Handbook of Mechanical Damping and Acoustical Dynamic Properties of Rubbers and Elastomers

Handbook of mechanical, damping and acoustical, dynamic properties of rubbers and elastomers. By C. Massot and G. Rocherolles-Deslignieres, Science Indus- tries, Montereau, France, 1985. pp. 293, price FFr. 400. ISBN 2-905906-02-2

British Polymer JournalVolume 18, Issue 6 p. 404-404 Book Review Handbook of mechanical, damping and acoustical, dynamic properties of rubbers and elastomers. By C. Massot and G. Rocherolles-Deslignieres, Science Indus- tries, Montereau, France, 1985. pp. 293, price FFr. 400. ISBN 2-905906-02-2 A. W. Birley, A. W. BirleySearch for more papers by this author A. W. Birley, A. W. BirleySearch for more papers by this author First published: November 1986 https://doi.org/10.1002/pi.4980180627AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume18, Issue6November 1986Pages 404-404 RelatedInformation

The design and use of rubber bearings for vibration isolation and seismic protection of structures

The development of rubber structural bearings for civil engineering applications is described. Rubber bridge bearings are designed to be stiff vertically and soft horizontally. Bearings with these characteristics can be designed from a knowledge of the compression characteristics of rubber blocks. A formula for the compression modulus in terms of the shape factor of the rubber block is given. Both natural and synthetic rubber (neoprene) are normally satisfactory; although stiffening of neoprene may occur where temperatures are at or below 0 degrees C for extended periods. Relevant static and dynamic properties of rubber and the extension of the design methods to provide seismic protection for buildings are described. For anti-seismic bearings the very low horizontal stiffness required may lead to a tall unstable bearing, and detailed consideration of this stability may be required. The possible buckling of the mount under the vertical load must also be considered. It is also important to select the correct degree of damping in the bearing material. (TRRL)

Effect of cycle asymmetry on the dynamic properties of rubbers in tension

The dynamic properties of rubbers have been investigated at large extensions in asymmetric cycles. Methods of calculating the characteristics of the elastic C∞ and hysteretic A properties of rubbers in two regimes are presented: 1) when the harmonic strain amplitude e0 and the mean strain ɛ are given; 2) when the harmonic displacement amplitude w0 of the rubber specimen and a spring dynamometer connected in series and the static load Qst are given. It is shown that in the case of vulcanizates based on crystallizing rubbers and active fillers in the region of strains e0, e and loads Qst causing crystallization during extension C∞ and A increase with increase in e0, e, and Qst. The variation of C∞ and A with e0, e, and Qst is qualitatively different for different types of deformation.

Nonlinearity of the dynamic properties of rubbers at large inhomogeneous compressive deformations

The isothermal inhomogeneous harmonic compression has been calculated for a material with nonlinear elastic characteristics and a hyperbolic relaxation time distribution. The experimental data for rubbers satisfactorily confirm the theory. The proposed characteristics of the elasto-hysteresis properties of rubbers do not depend on the test piece geometry and are functions of the degree of deformation.

Measurement of the Dynamic Modulus of Rubber at Very Small Amplitudes with an Optical Interferometer

Abstract A method of measuring very small differences of optical path using light modulation by an interferometer has been described. This enables one to measure amplitudes of mechanical vibrations of the order of 0.01 A or even smaller. We have used this method to measure the dynamic modulus of rubber at very small amplitudes. It is desirable to use this method for measuring the dynamic modulus of rubber and other highly elastic substances, firstly because in accuracy and simplicity it has certain advantages over existing acoustic methods. In the second place, it enables one to work at very small amplitudes and, in association with other methods, over a very wide range of amplitudes of deformation. This is of interest in connection with the general theory of the dynamic properties of rubber, and in particular, for checking the linearity of these properties, that is, the independence of the modulus and the loss on the amplitude, in particular for filled rubbers. We will briefly describe the apparatus with which the measurements were made. It consists of a Michelson interferometer and a source of monochromatic light. The interference pattern (lines of equal width) is projected onto the cathode of a photomultiplier. The output of the photo multiplier is fed to the input of a narrow-band filter, to the output of which the measuring instrument is connected. The mirror on the interferometer is set up so that the whole of the interference pattern, or the greater part of it, is uniformly illuminated. If now one of the mirrors vibrates with a frequency ω and an amplitude of z, then the difference in path between the interference beams will vary with a frequency of ω and the intensity of the light falling on the photomultiplier will also change. The current through the photomultiplier will be modulated with a frequency of ω. The first harmonic of the photocurrent will be I1=AJ1(4τz/λ), where λ is the wavelength of light; A is a coefficient depending on the intensity of the interfering beams and on their difference of path with the mirror at rest; I1 is a first order Bessel function.

Effect of Vulcanization on the Dynamic Properties of Rubber

Abstract It is a known fact that the mechanical properties of rubber depend essentially upon the density (i.e., the crosslink density) of the vulcanization network. The dependence of the “equilibrium” (statistical) modulus of elasticity upon the concentration of crosslinks as well as the dependence of the tensile strength —has been studied in a series of investigations. In contrast to this, analogous investigations of the dynamic mechanical characteristics are practically nonexistent. We have undertaken our present work with the hope of filling this gap. Series of gum compounds were prepared from natural (smoked sheet) and synthetic polyisoprene (SKI), sodium butadiene (SKB), butadiene-styrene (SKS-30A), and butadiene-nitrile (SKN-26) rubbers which varied in their degree of vulcanization. The percentage of sulfur and accelerator were varied as were the temperature and the time of vulcanization. The mechanical-dynamic characteristics of the rubber at a predetermined impact pressure—the rebound elasticity and the dynamic elastic modulus were studied with the pendulum elastometer KS over a temperature range of 20–100° C. The duration of the stress was .03/.05 second. We estimated the concentration of crosslinks in the rubber samples from the magnitude of the equilibrium modulus. In order to determine this characteristic, we compressed specimens which were 20 mm in height and 10 mm in diameter 15% and studied the relaxation of stress. The specimens were also tested on the pendulum elastometer. Heppler's consistometer operating on the lever weight principle, was adapted for our measurements. The experiments were conducted at 60° C, the thermostatic control being effected with the help of Heppler's ultrathermostat.

Behavior of Rubber in Compression under Dynamic Conditions

Abstract At first sight, it would appear that previous investigators, have dealt fully with the main variables affecting the behavior of rubber. For instance, many publications have dealt with the effects of such variables as frequency, amplitude of deformation, and temperature. A closer examination of these publications, however, brings out the fact that no attempt has been made to keep the amplitude of deformation constant in any of the previous investigations into the effect of temperature at low temperatures. It is important that the amplitude of deformation should be kept constant, since both the stiffness and hysteresis energy absorbed per cycle depend on its value. It does not appear that work has been published on the frequency dependence of the hysteresis energy absorbed per cycle at low temperatures, nor even on how the hysteresis energy absorbed per cycle varies with temperature. For these reasons alone, the main investigation was initiated, and the results are presented to show the effects of frequency, temperature, and amplitude of deformation on the dynamic properties of rubber.

Nonlinearity in the Dynamic Properties of Rubber

Abstract The first two sections of this paper deal with the necessity for amending the classical Newtonian equations by assuming a nonlinear stress-strain curve in order to account for the presence of a considerable amount of second harmonic of the test frequency in the restoring forces in a rubber, in both forced-vibration and positive-displacement dynamic testers. The nonlinear stress-strain curve is applied also to a damped free-vibration curve of the Yerzley type, and is shown to account for the asymmetry of the envelope of the vibration curve. The latter part of the paper obtains a relationship between the dynamic modulus of loaded rubbers and amplitude of vibration, leading to equations analogous to those used in rheology to deal with rate of shear effects in non-Newtonian liquids, and to explain the effects of fillers on the static modulus and hardness of vulcanized rubbers. A resonance curve from a resonant vibrator is analyzed and the variation of modulus with amplitude is shown to exhibit the typical thixotropic effect associated with loaded rubbers subjected to vibrations. The last section discusses how the decrease of modulus with increasing amplitude can be attributed to two different mechanisms: (1) thixotropic breakdown of filler structure, (2) in compression, nonlinearity of the stress-strain curve.

Hysteresis in Rubber

IN the discussion following a recent series of lectures given in the University of Nottingham on the dynamic properties of rubber, it became evident that the methods of specifying and measuring the amount of hysteresis in rubber are subjects of controversy. Two terms in current use for specifying hysteresis are ‘percentage damping’ and ‘resilience’, as defined in the accompanying diagram.

Free and Forced Vibration Methods in the Measurement of the Dynamic Properties of Rubbers

Abstract Previous work on the shear elastic modulus and damping factor of rubber has been carried out chiefly by two methods. Some workers have deduced these quantities from the natural frequency and rate of decay of the free vibrations of a simple system comprising a mass and a rubber spring; others have obtained the values from the resonance curve of such a system under forced vibration excited by a known harmonic force of variable frequency. The derivation of the shear modulus and damping factor from the experimental results is in both cases based on the assumption for rubber of a simple mechanical model consisting of a spring with a viscous dashpot in parallel. In order to ascertain whether the results from the two methods (more particularly for the damping factor) correspond, measurements have been carried out by both methods on the same rubber test piece on the same mechanical system and under identical conditions. The approximate agreement between the results thus obtained justifies the basic assumptions underlying these methods.

The Variation with Temperature of the Dynamic Properties of Rubber and Synthetic Rubberlike Materials. II. Compounded Rubbers

Abstract The whole of the dynamic modulus results may be summarized as follows. (1) A general sensitivity to temperature over the range studied is shown by all rubbers, natural and synthetic. (2) Natural rubber is least sensitive, followed by Neoprene-GN and GR-S. Next in order come Neoprene-YD and butadiene-acrylonitrile copolymers with low acrylonitrile contents. In general, the higher the acrylonitrile content, the more sensitive to temperature is the polymer. Neoprene-Z is only slightly less sensitive than Hycar OR-15 (45–55). (3) Broadly speaking, the effect of compounding with P-33 black and gas black is to increase the sensitivity to temperature. Notable exceptions are Neoprene-GN and GR-S containing extender, which appear almost unchanged, and Neoprene-YD, which shows a decreased sensitivity with loading. (4) It is evident from the results that any specification for dynamic modulus should be accompanied by a specified temperature of test; in design, account must be taken of the variations which it has been shown can be quite considerable for synthetic rubbers now coming into commercial use, even under normal seasonal variation of temperature. (5) Static methods of determining freeze points, e.g., torsion and bending tests, in general place materials in a similar order with respect to their low-temperature behavior as the present dynamic experiments, although no appreciable temperature effects are noted in the temperature range of the experiments discussed here. The results of resilience measurement are not easy to summarize. Suffice it to say that, over the limited range of temperatures investigated, very great differences in resilience are observed between different polymers. The superiority of natural rubber is again evident, although it is somewhat less marked in loaded stocks. In the case of Thiokol-RD and Hycar OR-15, minima in the resilience curves are indicated at 23° C and about 10° C, respectively. This has been reported by previous workers. In all polymers the resilience-temperature curve is in two parts, with a more or less sharply defined transition point, the temperature of which seems to depend largely on the chemical structure of the polymer. Again this is confirmed to some extent by reference to the literature.