Effect of Carbon Black on Dynamic Properties of Rubber Vulcanizates
TL;DR: In this paper, the dynamic properties of rubber vulcanizates with carbon black as a filler are investigated. But the effect of adding carbon black to the rubber is not discussed.
Abstract: The term dynamic properties as applied to elastomers refers to the response to periodic or transient forces which do not cause failure or appreciable fatigue (permanent change of properties) during the investigation. Generally this is limited to vulcanizates subjected to deformations not exceeding about 25%; and generally the dynamic properties are measured after several cycles or (in a transient experiment such as resilience) after several preconditioning transients, so that the Mullins effect or difference between first and second strain cycles is not of consequence. Thus, dynamic properties represent the viscoelastic properties of vulcanizates at deformations below about 25%, after reaching a pseudo-equilibrium state. The dynamic properties of rubber are altered tremendously by the addition of a filler. The scope of this article is restricted to the dynamic properties of rubber vulcanizates with carbon black as a filler. The effect covered in this article are important in designing rubber comp...
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TL;DR: In this article, a detailed experimental investigation probing the material response of carbon black filled Chloroprene rubber subjected to different time-dependent strain histories is presented, based on the experimental data a new constitutive model has been developed.
Abstract: The mechanical behavior of elastomeric materials is known to be rate-dependent and to exhibit hysteresis upon cyclic loading. Although these features of the rubbery constitutive response are well-recognized and important to its function, few models attempt to quantify these aspects of response perhaps due to the complex nature of the behavior and its apparent inconsistency with regard to current reasonably successful models of rubber elasticity. In this paper a detailed experimental investigation probing the material response of carbon black filled Chloroprene rubber subjected to different time-dependent strain histories is presented. Some of the key observations from the experiments are: (1) both filled and unfilled elastomers show significant amounts of hysteresis during cyclic loading; (2) the amount of carbon black particles does not strongly influence the normalized amount of hysteresis; (3) both filled and unfilled elastomers are strain-rate dependent and the rate dependence is higher during the uploading than during the unloading; (4) at fixed strain, the stress is observed to approach the same equilibrium level with relaxation time whether loading or unloading. Based on the experimental data a new constitutive model has been developed. The foundation of the model is that the mechanical behavior can be decomposed into two parts: an equilibrium network corresponding to the state that is approached in long time stress relaxation tests; and a second network capturing the non-linear rate-dependent deviation from the equilibrium state. The time-dependence of the second network is further assumed to be governed by the reptational motion of molecules having the ability to significantly change conformation and thereby relaxing the overall stress state. By comparing the predictions from the proposed three-dimensional constitutive model with experimental data for uniaxial compression and plane strain compression we conclude that the constitutive model predicts rate-dependence and relaxation behavior well.
936 citations
TL;DR: In this paper, the intrinsic potential of carbon nanotubes as reinforcing filler in elastomeric materials is demonstrated, despite a poor dispersion, small filler loadings improve substantially the mechanical and electrical behaviors of the soft matrix.
670 citations
TL;DR: In this article, the authors discuss the nature of rubber-filler interactions and their effects on rheological properties of uncured materials and discuss the relationship between bound rubber and flow properties.
646 citations
TL;DR: The role of active fillers like carbon black and silica has been studied in the rubber matrix for a better understanding of the rubber performance and the mechanism of reinforcement as mentioned in this paper, in particular the influence of basic properties of carbon blacks, such as specific surface area, structure and surface activity on the Payne-effect, was investigated with the Rubber-Process-Analyzer (RPA) which allows a testing of the strength of the filler network and the filler-polymer interaction in the green compound as well as in the vulcanizate in a wide range of shear amplitudes.
Abstract: The role of active fillers like carbon black and silica has been studied in the rubber matrix for a better understanding of the rubber performance and the mechanism of reinforcement. In particular the influence of basic properties of carbon blacks, such as specific surface area, structure and surface activity on the Payne-effect, was investigated with the Rubber-Process-Analyzer (RPA) which allows a testing of the strength of the filler network and the filler-polymer interaction in the green compound as well as in the vulcanizate in a wide range of shear amplitudes. A comparison between carbon black and the silica-silane system leads to further scientific findings for the understanding of the dynamic behavior of filled rubber compounds.
625 citations
TL;DR: In this article, a review describes recent research about reinforcement in elastomers where the main intention is to gain insight into the relationship between disordered filler structure on different length scales and reinforcement and to microscopic mechanisms of strain enhancement.
Abstract: The review describes recent research about reinforcement in elastomers where the main intention is to gain insight into the relationship between disordered filler structure on different length scales and reinforcement and to microscopic mechanisms of strain enhancement. Several theoretical concepts will be discussed together with very recent experimental findings related to hydrodynamic reinforcement, rigid filler aggregates with fractal structure and polymer adsorption on heterogeneous filler surfaces. Based on the new concepts, we present several recent efforts to understand typical effects in filled rubbers that have an extraordinary practical importance (for example, stress softening of carbon black filled rubbers during repeated large strain stretching and during small strain dynamic excitations).
584 citations