Rubber nanocomposites modeling

Takala M, Ranta H, Nevalainen P, Pakonen P, Pelto J, Karttunen M, Virtanen S, Koivu V, Pettersson M, Sonerud B, Kannus K (2010) Dielectric properties and partial discharge endurance of polypropylene-silica nanocomposite. IEEE Trans Diel Electr Insul 17 1259-1267 Tanaka T, Kozako M, Fuse N, Ohki Y (2005) Proposal of a multi-core model for polymer nanocomposite dielectrics. IEEE Trans Diel Electr Insul 12 669-681 Vaughan AS, Swingler SG, Zhang Y (2006) Polyethylene nanodielectrics the influence of nanoclays on structure formation and dielectric breakdown. Trans lEE Jpn 126 1057-1063 Venkatesulu B, Thomas MJ (2010) Erosion resistance of alumina-filled silicone rubber nanocomposites. IEEE Trans Diel Electr fiisul 17 615-624 Weibull W (1951) A statistical distribution function of wide applicability. J Appl Mech Trans ASME 18 293-297... 

Rubber nanocomposites represent a very attractive field of materials science, bringing new challenges for scientists working in experimental as well as simulation areas. At present the most popular models for predicting the Pa5me effect are ... 

Rubber-based nanocomposites were also prepared from different nanofillers (other than nanoclays) like nanosilica etc. Bandyopadhyay et al. investigated the melt rheological behavior of ACM/silica and ENR/silica hybrid nanocomposites in a capillary rheometer [104]. TEOS was used as the precursor for silica. Both the rubbers were filled with 10, 30 and 50 wt% of tetraethoxysilane (TEOS). The shear viscosity showed marginal increment, even at higher nanosilica loading, for the rubber/silica nanocomposites. All the compositions displayed pseudoplastic behavior and obeyed the power law model within the experimental conditions. The... 

In the second part of this chapter, an illustrative example of PARAFAC analysis for three-way data obtained in an actual laboratory experiment is presented to show how PARAFAC trilinear model can be constructed and analyzed to derive in-depth understanding of the system from the data. Thermal deformation of several types of poly lactic add (PLA) nanocomposites xmdergoing grass-to-rubber transition is probed by cross-polarization magic-angle (CP-MAS) NMR spectroscopy. Namely, sets of temperature-dependent NMR spectra are measured under varying clay content in the PLA nanocomposite samples. While temperature strongly affects molecular dynamics of PLA, the clay content in the samples also influences the molecular mobility. Thus, NMR spectra in this study become a three-way... 

Barrier properties of a rubber matrix are remarkably improved thanks to clay addition. The tortuous path model is proposed to explain this phenomenon. In a NR/Mt nanocomposite prepared from emulsion blending, 1, 2 and 3 phr of clay led to more than 35% and to about 45% and 50% reduction of oxygen permeability, respectively. " 3 phr of OC (Mt/ didodecyl methyl amine) gave a 50% reduction of the oxygen permeability and a 40% reduction of toluene absorption at 20 °C. About 10% and 15% reduction of oxygen permeability were obtained with 5 and 10 phr of OC, respectively, and 30% reduction of toluene absorption was achieved with 15% OC, at 30 °C. ... 

DMA analysis of NR/Ti02 nanocomposites prepared by latex blending showed that its Tg and activation energy are higher than the pure NR. ° According to their dynamic model, the decomposition activation energy of blank sample (vulcanized rubber) and the samples which contained Ti02 with 0.1%, 0.5%, 1.0%, 2.0% were 229.99, 231.085, 201.727, 219.107, 208.249 kJ mol and their pre-exponential factor of dynamic model were found to be 5.07 x 10 8.46 x 10 , 2.94 x 10 8.03 x 10 , 1.04 x 10 s respectively. 

Solubility increase mechanism depends on the interaction between the penetrants and nanofillers. The functional groups of nanofillers such as hydroxyl when occur on the surface of the inorganic nanofiller phase in rubber composites may interact with polar gases such as SO2. This condition can increase the penetrant solubility in the nanocomposite rubbers and, in turn, increase the gas permeability. The solubility increase mechanism model due to permeation coefficient parameter of gas, P is described using the Arrhenius equation ... 

The Nielsen model has been a popular theory, originally used to explain polymer lay nanocomposites. This model is used to describe the tortuosity effect of plate-like particulates of filled rubber polymer composite on the gas permeation. An increase in barrier properties of gas permeation of rubber polymer nanocomposites is a result of the impermeable nature of filler particles which creates a long path of penetrant molecule by directing them around the particle. 

Recently, many models for predicting the diffusion and permeation pattern or mechanism still have been developed to fit the experimental data in various types of polymer composite as well as nanocomposite. Many researchers try to clearly know a characteristic of composite and nanocomposite polymer with different type, shape and amount of filler in the polymer matrix. This basic knowledge of diffusion mechanism of composite rubber material is useful for industrial field to develop the suitable material in several conditions of usage such as a long duration of tires in automobile industrial. However, most of other models have been developed by modification from Neilsen model as a basic equation. 

Abstract The present chapter is written as an introduction towards this book on nonlinear viscoelasticity of rubber composites and nanocomposites. Rather than introducing the concept of the book to the readers this chapter reveals the basics behind rubber viscoelasticity and explains both linearity and nonlinearity from this behavior. Various filler reinforced rubbers are introduced emphasising the flow behavior of such nanocomposites. Major mathematical models proposed by Kraus, Huber and Vilgis and Maier and Goritz for the Payne Effect are briefly addressed based on the filler matrix interactions existing in the composite systems. 

Very interesting studies of natural rubber reinforcement with ZnO nanoparticles were performed by scientists from India, under the direction of Sabu Thomas [62]. The goal of these studies was to characterize the viscoelastic behavior and reinforcement mechanism of ZnO nanoparticles introduced into the rubber matrix. They have presented a constrained polymer model based on a rubbery region and a ZnO nanoparticle. Very interestingly, the authors presented a core-shell morphology model and constrained polymer model to explain the constrained polymer chains in NR/ZnO nanocomposites [62]. Thanks to this research and the proposed models, it is possible to understand the behavior of nanofillers in the polymer matrix and maybe in the future to develop an ideal nanofiller for use in the rubber matrix. 

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