Papers by Keyword: Rubber Composites

Abstract: Results of scientific researches in the field of creation of self-adhesive radiation shielding materials on the basis of polymers are presented in this article. It is stated, that radiation shielding coverings on the basis of ethylene propylene rubber are more preferable than coverings on the basis of BSR and SBS. Materials on the basis of ethylene propylene rubber possess high hardness at scaling from metal (more than 600 N/m) and hardness at breakoff from concrete (more than 0,1 MPa), have a high linear absorption coefficient.

Abstract: Based on the connection between macroscopic and microscopic characteristics of carbon black filled rubber composites, Representative Volume Element (RVE) containing one single particle has been proposed, and three dimensional cubic RVE has been established to study and analyze the macroscopic mechanical properties of the carbon black filled rubber composites by the micromechanical finite element method. The research shows that the stiffness of the composite is increased with the increase of the volume fraction of carbon black filler particles. By comparison, it is shown that the results of the predictions on the stress-strain behavior of the rubber composite made with the cubic RVE numerical models containing one spherical particle are in good agreement with the experimental results for seven and fifteen percent carbon black filler content, but there is some discrepancy between them for twenty-five percent carbon black filler content. The results of the predictions on the stress-strain behavior of the rubber composite made with the cubic RVE numerical models containing one cubical particle are higher than the experimental results, and the higher the carbon black filler content, the greater is the discrepancy between them.

Abstract: In this paper, Representative Volume Element with random distribution pattern has been built and applied to study and analyze the macro mechanical properties of the carbon black filled rubber composites by the micromechanical finite element method. And numerical simulations under uniaxial compression have been made by two-dimensional plane stress model. The periodic boundary conditions are imposed on each Representative Volume Element in order to ensure the compatibility of the deformation field. The dependence of the macroscopic stress-strain behavior and the effective elastic modulus of the composites, on particle distribution pattern, particle volume fraction and particle stiffness has been investigated and discussed. It is shown that the stiffness of the composite is increased considerably with the introduction of carbon black filler particles, and the effective elastic modulus of the composite is increased with the increase of the particle volume fraction.

Abstract: In this study, rice husk fiber (RHF) was used as a reinforcing filler for natural rubber (NR). NR composites were prepared at various RHF contents, i.e., 10, 20, 30, 40 and 50 phr. Sulfur conventional vulcanization was used. Effect of RHF content on cure characteristics, mechanical properties and morphological properties of NR composites were investigated. The results showed that scorch and cure times of RHF/NR composites were not affected by increasing RHF content. Crosslink density, tensile strength, elongation at break and tear strength of NR composites slightly decreased with increasing RHF content whereas M100 and M300 of the composites slightly increased with increasing RHF content.

Abstract: In this paper, the micromechanical finite element method based on Representative Volume Element has been applied to study and analyze the macro mechanical properties of the carbon black filled rubber composites by using two-dimensional plane stress simulations and three-dimensional axisymmetric simulations under uniaxial compression respectively. The dependence of the macroscopic stress-strain behavior and the effective elastic modulus of the composites, on particle shape, particle area/volume fraction and particle stiffness has been investigated and discussed. Additionally, the simulation results of the two-dimensional plane stress model and the three-dimensional axisymmetric model are evaluated and compared with the experimental data, which shows that the two-dimensional plane stress simulations generate poor predictions on the mechanical behavior of the carbon black particle reinforced rubber composites, while the three-dimensional axisymmetric simulations appear to give a better prediction.

Abstract: Carbon nanotubes (CNTs) reinforced natural rubber (NR) composite was fabricated in a solvent casting method. The tensile properties and electrical resistivities were investigated. As a comparison, carbon black (CB) reinforced NR was also prepared in the same method. The initial modulus of NR/3 wt% CNT composite was about 1.6 times as large as that of NR/ 3wt% CB composite. NR/CNT composite had a percolation threshold value of about 5 wt% CNTs. The morphology of fillers and composites were observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The improved properties of NR/CNT composites were attributed to the excellent mechanical and electrical properties of CNTs and its formed network, which must be benefit to electromagnetic interference shielding properties of NR composites.

Abstract: The typical roof tiles made from soil or clay will be limited because it destroyed the farmland. On the other hand, the old tire and waste plastic increase year and year, which bring a serious environmental problem. So the roof tiles made from old tire and waste plastic will help a lot to decrease above environmental pressure. To get a suitable formula of roof tiles made from waste rubber tire powder and waste plastic, the present article studied mechanical performance of a series of composites. Then a preferred formula was got through comparing the mechanical performance.

Abstract: Composites of rubbers such as ethylene – propylene and acrylonitrile – butadiene with micro size Fe¬3O4, Fe2O3, and nano size Fe3O4 as the fillers were tested. Iron oxides were found to be active fillers which improved mechanical properties of elastomers. Additionally, they also changed their magnetic properties. Furthermore, the surface of micro size Fe3O4 was modified to upgrade mechanical properties of the vulcanizates. Itaconic acid, methacryloxypropyltrimethoxysilane and monododecyl maleate were used as modifying agents. To improve dispersion of applied fillers in polymers matrix, non-ionic (NF-PEG), anionic (calcium stearate ), cationic (DTAB, DTAC, DDAB, CTAD) and ionic liquids (HMIMBF4, BMIMPF6, OMIMPF6) were used. It was observed that both non-modified and modified micro iron oxides and nano iron oxides improved the properties of the vulcanizates the most effectively.

Abstract: Silica fillers are used in rubber composites to modify their dynamic-mechanical properties. Three fillers are used: a commercial filler of precipitated silica type Vulkasil- S and two fillers obtained by its treatment in different ways: thermally and hydrothermally. The purpose is not only to obtain higher hysteresis of the composite at low temperatures and lower hysteresis at elevated temperature (which is optimal for good tire performance), but to understand the reasons of such changes in elastomer materials behavior and also possibilities to increase the corresponding trends. Both modified fillers exhibited required trends in comparison with the original commercial one. More detailed analyses of their dynamical behavior indicate interdependence between of filler particle size, morphology of particle aggregates and ratio of elastic to loss moduli, influencing all together the dynamic properties of products.