http://staff.ulsu.ru/moliver/ref/polymers/pott11.pdf

Graphene-based polymer nanocomposites

Thermal conductivity of carbon nanotubes and their polymer nanocomposites: A review

When rubber slides on a hard, rough substrate, the surface asperities of the substrate exert oscillating forces on the rubber surface leading to energy “dissipation” via the internal friction of the rubber. I present a discussion of how the resulting friction force depends on the nature of the substrate surface roughness and on the sliding velocity. I consider in detail the case when the substrate surface has a self affine fractal structure. I also present a theory for the area of real contact, both for stationary and sliding bodies, with elastic or elastoplastic properties. The theoretical results are in good agreement with experimental observation.

/pdf/theory-of-rubber-friction-and-contact-mechanics-4jc393dfj5.pdf

Theory of rubber friction and contact mechanics

A review on the mechanical and electrical properties of graphite and modified graphite reinforced polymer composites

Elastomeric biomaterials for tissue engineering

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).

Reinforcement of Elastomers

The viscoelastic properties of (mostly carbon black) filled elastomers are reviewed with emphasis on the strain-dependence of the complex dynamic modulus (Payne effect) Considerable progress has been made in the past in relating the typical dynamical behavior at low strain amplitudes to a cyclic breakdown and reagglomeration of physical filler-filler bonds in typical clusters of varying size, including the infinite filler network Common features between the phenomenological agglomeration/deagglomeration Kraus approach and very recent semi-microscopical networking approaches (two aggregate VTG model, links-nodes-blobs model, kinetical cluster-cluster aggregation) are discussed All semi-microscopical models contain the assumption of geometrical arrangements of sub-units (aggregates) in particular filler network structures, resulting for example from percolation or kinetical cluster-cluster aggregation These concepts predict some features of the Payne effect that are independent of the specific types of filler These features are in good agreement with experimental studies For example, the shape exponent m of the storage modulus, G′, drop with increasing deformation is determined by the structure of the cluster network Another example is a scaling relation predicting a specific power law behavior of the elastic modulus as a function of the filler volume fraction The exponent reflects the characteristic structure of the fractal filler clusters and of the corresponding filler network The existing concepts of the filler network breakdown and reformation appear to be adequate in describing the deformation-dependence of dynamic mechanical properties of filled rubbers The different approaches suggest in a common manner that there is a change of filler structure with increasing dynamic strain However, in all cases additional assumptions are made about the accompanying energy dissipation process, imparting higher hysteresis to the filled rubber This process may be slippage of entanglements (slip-links) in the transition layer between bound rubber layer and mobile rubber phase, and/or partially release of elastically ‘dead’ immobilized rubber trapped within the filler network or agglomerates

Recent Advances in the Theory of Filler Networking in Elastomers

The chapter considers the disordered nature of filler networks on different length scales and relates it to the specific reinforcing properties of active fillers in elastomer composites. On nanoscopic length scales, the surface structure and primary aggregate morphology of carbon blacks, the most widely used filler in technical rubber goods, are analyzed by static gas adsorption and transmission electron microscopy (TEM) techniques, respectively. They are found to be closely related to two distinct disordered growth mechanisms during carbon black processing, surface growth and aggregate growth.

The Role of Disorder in Filler Reinforcement of Elastomers on Various Length Scales

Modified and unmodified multiwalled carbon nanotubes in high performance solution-styrene-butadiene and butadiene rubber blends

A basic theoretical concept of rubber friction on rough surfaces is presented that relates the frictional force to the dissipated energy of the rubber during sliding stochastic excitations on a broad frequency scale. It is shown that this is of high relevance for tire traction and allows for a prediction of the likely level of friction of tread compounds on the basis of viscoelastic data. The impact of both, the frequency dependent loss- and storage modulus on the frictional force during sliding of tires on rough tracks, is demonstrated quantitatively for different sliding velocities. The effect of the surface roughness of road tracks is described by three characteristic surface descriptors, i.e., the fractal dimension and the correlation lengths parallel and normal to the surface. These descriptors can be obtained from a fractal analysis of the road texture via stylus- or laser measurements. In particular, it is shown that the applied model of rubber friction is in agreement with the classical f...

Manfred Klüppel

Papers

Reinforcement of Elastomers

Recent Advances in the Theory of Filler Networking in Elastomers

The Role of Disorder in Filler Reinforcement of Elastomers on Various Length Scales

Modified and unmodified multiwalled carbon nanotubes in high performance solution-styrene-butadiene and butadiene rubber blends

Rubber Friction on Self-Affine Road Tracks