Effect of filler on relaxation-time spectra of filled polymers

The frequency and temperature dependence of the complex shear modulus G* and tan δ of epoxide compositions with various fillers have been studied. Relaxation-time spectra of filled polymers with various fillers have been plotted by the Ninomi-Ferry method. The principles governing changes in the shape of the spectrum curves with increase in filler concentration have been observed, enabling conclusions to be drawn on the effect of the filler on the change in properties of a polymer matrix and the deformation conditions of the polymer layers between the filler particles.     

Fractial parameterization of the structure of filled polymers

It is suggested to consider the structure of a filled polymer as a set of two or more multifractals. It is shown experimentally that the basic factor determining the fractal dimension of distribution of a disperse filler in the polymer is the size distribution of filler particles.Moscow State Open University, Moscow, Russia. Translated from Mekhanika Kompozitnykh Materialov, Vol. 35, No. 3, pp 269–290, 1999.     

Effect of filler structure on strength of some carbon composites

Filler structure and its connection with the strength of composite graphite-plastic materials have been studied. It has been shown that the filler surface affects the cross-linking conditions of the polymeric binder, which determines the mechanical properties of the material. The dependence of the strength of graphite plastics on dimensions of the filler crystallites can be represented by an equation of the Petch type, in which the coefficients have a definite physical meaning.     

Supermolecular structure and properties of polymers

Questions relating to methods of obtaining supermolecular structures and their effect on the properties of polymers are considered.Presented at 2nd All-Union Conference on Polymer Mechanics, Riga, November 10–12, 1971.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 3, pp. 409–415, May–June, 1972.     

The role of sonic shocks between two- and three-phase states in porous media

Flowof threefluids in porousmedia is governed by a systemof two conservation laws. Shock solutions are described by curves in state space, which is the saturation triangle of the fluids. We study a certain bifurcation locus of these curves, which is relevant for certain injection problems. Such structure arises, for instance, when water and gas are injected in a mature reservoir either to dislodge oil or to sequestrate CO₂. The proof takes advantage of a certain wave curve to ensure that the waves in the flow are a rarefaction preceded by a shock, which is in turn preceded by a constant two-phase state (i.e., it lies at the boundary of the saturation triangle). For convex permeability models of Corey type, the analysis reveals further details, such as the number of possible two-phase states that correspond to the above mentioned shock, whatever the left state of the latter is within the saturation triangle.     

Theory of filled polymers and the problem of modifying the structure and properties of polymers with fillers

An attempt is made to explain the effect of fillers on the structure and properties of polymers. The effect of fillers on the state of thermodynamic equilibrium and the stability of polymer structure and properties is also considered.Kiev Shevchenko State University. Translated from Mekhanika Polimerov, No. 6, pp. 1031–1041, November–December, 1970.     

The supramolecular structure of polymers and its effect on their mechanical properties

A study is made of the conditions of formation of various supramolecular structures in polymers and their effect on the mechanical properties. The nonuniformity and instability of the structure, and hence of the mechanical properties, may be controlled by means of artificial crystallization nuclei.Mekhanika polimerov, Vol. 1. No. 1. pp. 5–16, 1965The research was carried out at the L. Ya. Karpov Physicochemical Research Institute.     

Effect of a filler,aging, and remelting on the distribution of the spherulitic structure in polyformaldehyde

The distribution of the spherulitic structure of a crystalline polymer has been experimentally investigated with reference to the example of polyformaldehyde (PF). Experimental histograms and distribution curves have been constructed for the distances between the centers of the spherulites in unfilled PF and PF filled with mullite particles of varying shape and size before and after aging and multiple melting. Similar data have also been obtained for the angles between the lines of centers of the spherulites. The results are closely correlated with the changes in the structure and the physicochemical and mechanical properties of PF accompanying the above-mentioned processes.Shevchenko Kiev State University, Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Mekhanika Polimerov, No. 1, pp. 11–16, January–February, 1971.     

Effect of production technology upon the supramolecular structure of crystalline polymers

The supramolecular structure and some other properties (density, microhardness) of high-density polyethylene and polycaprolactam specimens, molded under various conditions and aged for periods up to five months, have been studied.The change in the nature of the supramolecular structure and properties of the tested materials was determined in relation to molding conditions and aging time. It was found that the properties of these materials are determined by their supramolecular structure.Mekhanika Polimerov, Vol. 1, No. 2, pp. 9–14, 1965     

Mechanism by which tension on the fibrous filler affects the structure and the strength of wound glass-plastics

Conclusions 1. We have studied how the structure of glass-plastics wound with twisted threads is affected by tension on the fibrous filler. The trend of changes in fiber content and porosity, as well as an increasingly nonuniform distribution of the reinforcing filler over the thickness, has been established.2. The effect of a nonuniform filler distribution over the thickness on the tensile strength has been evaluated. The calculated and the experimental curve of strength as a function of the tension have been compared, the former taking into account variable porosity, fiber content, and nonuniformity of fiber distribution over the thickness.3. It has been demonstrated that the change in the strength characteristics of a wound glass-plastic as a function of the tension on the reinforcing filler during winding is due to a combined complex effect of such factors as the overall fiber content and porosity, a nonuniform fiber distribution over the thickness, the fiber orientation, and the degree of mechanical damage in threads due to their interaction with the active components of the winding machine.Report presented at the Third All-Union Conference on Polymer Mechanics. Riga, November 10–12, 1976.Translated from Mekhanika Polimerov, No. 3, pp. 439–444, May–June, 1977.     

Supramolecular structure and incipient cracks in three-dimensional stitched amorphous polymers

The electron-microscopic method was used to study the structure of unsaturated polyester films. The initial submicrocracks developing in the loaded films were studies by the low-angle x-ray diffraction method. It is shown that for these polymers a typical feature is the globular structure with a globule diameter of 10³–3·10³ Å, and the transverse dimension of the submicrocracks developing under the action of a load practically coincides with the globule diameter.     

Concerning the investigation of the supermolecular structure of polymers with a three-dimensional network

The results of an investigation of the structure and properties of a series of crosslinked polymers are presented. It is shown that the structure is determined by the chemical structure of the starting components and the method of synthesis.Institute of Chemistry of High-Molecular Compounds, Academy of Sciences of the Ukrainian SSR, Kiev. Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Mekhanika Polimerov, No. 5, pp. 934–936, September–October, 1970.     

Behavior of the supermolecular structure of oriented amorphous-crystalline polymers under cyclic loading

Equipment has been developed for investigating small-angle X-ray diffraction in various phases of the loading period in cyclically extended polymers. The behavior of the large-period structure of oriented polycaprolactam (kapron) films in cyclic extension has been studied. The results are compared with the data on the behavior of the same structure in static tests.Mekhanika Polimerov, Vol. 4, No. 2, pp. 195–199, 1968     

Relationship between the molecular structure and certain mechanical properties of oriented polymers

The correlations between the molecular structure and intermolecular energy and the fatigue and elastic properties of fibers are considered. It is shown that the maximum of these properties corresponds to an optimal value of the intermolecular energy.Leningrad Branch of the All-Union Scientific-Research Institute of Synthetic Fibers. Translated from Mekhanika Polimerov, No. 4, pp. 734–735, July–August, 1969.     

The piezoelectric effect in polymers

A series of polymers with varying polarity and chain rigidity has been investigated. On the basis of the results obtained it is concluded that piezoelectric properties are to be found in polarized polymers with small dipole groups and a rigid chain due to their polarity.Mekhanika Polimerov, Vol. 4, No. 1, pp. 169–172, 1968     

The effect of a porous polyethylene matrix on the structure and mechanical and deformational properties of electroactive composites

Two types of new electroactive composite systems based on elastic substrates (porous polyethylene films) have been elaborated. The systems of the first type are composed of electroconductive polymers (polypyrrole and polyaniline) obtained by in situ oxidative polymerization of their monomers on porous polyethylene substrates. The composites of the second type contain a cross-linked polyelectrolyte, and they were prepared by polymerization of acrylic acid with a macromolecular cross-linker on the porous substrates. The mechanical properties and the deformational behavior of the porous films and composites have been investigated and analyzed. __________ Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 6, pp. 825–838, November–December, 2006.     

Strength properties of oriented amorphous linear polymers in relation to their structure

Tensile tests have been conducted at room temperature on uniaxially oriented films of a number of amorphous linear polymers. It has been shown that the mechanical properties of the oriented polymers in the glassy state are chiefly determined by two parameters of the structure—the degree of orientation of the macromolecule segments and the concentration of stressed chains per unit volume, irrespective of the molecular weight of the polymer and the orientational stretching conditions.Mekhanika Polimerov, Vol. 3, No. 3, pp. 455–460, 1967