Certain properties of filled partly plasticized polyvinylchloride

The effect of iron oxide as a filler for hard partly plasticized polyvinylchloride was studied. It was shown that the influence of iron oxide on polymer properties varies depending on the proportion of the filler used. When added in small quantities, it improves certain physico-mechanical properties of polyvinylchloride, such as, for instance, its hardness and wear resistance.Mekhanika Polimerov, Vol. 2, No. 6, pp. 813–816, 1966     

Effect of aging creep of polyestermalein resin/mineral filler composites

Long-term (More than 20 years) creep under compression of two polymer concretes, polyestermalein resin/mineral filler composites, was studied. The concretes differ with diabase filler size (d=5–10 mm and d=10–20 mm). It was shown that nonlinearity of viscoelastic properties of concrete increases as the size of filler particle decreases. Aging of the polymer concretes reduces their viscoelastic compliance and shortens the time interval necessary to reach equilibrium conditions under stable loading state.Presented at the Ninth International Conference on the Mechanics of Composite Materials, Riga, October, 1995.Institute of Theoretical and Applied Mechanics of the AS CR, Prague 9, Prosecká 74, Czech Republic. Central Laboratory of Physical-Chemical Mechanics of the BAS, Sofia 1113 Acad. Bontchev Street, IV km, Bl. 1. Published in Mekhanika Kompozitnykh Materialov, Vol. 32, No. 2, pp. 190–194, March–April, 1995.     

Adhesive and cohesive properties of filled Pentaplast

The authors study the influence of an inorganic filler (aluminum oxide) on the hardness of Pentaplast and its adhesion to steel. They show that the change in adhesion accompanying filling is due to changes in the cohesive properties of Pentaplast.Institute of Mechanics of Metal-Polymer Systems, Academy of Sciences of the Belorussian SSR, Gomel'. Translated from Mekhanika Polimerov, No. 6, pp. 1098–1101, November–December, 1975.     

Effect of fillers on the viscosity and viscoelasticity of low-density polyethylene melts. Communication 1

An investigation of low-density polyethylenes filled with up to 30% by volume dispersed particles, has shown that for both the matrix and the composites the apparent viscous flow activation energy does not depend on the shear stresses and increases starting from a certain filler concentration at which the conformation range in the matrix is depleted. The dependence of the relative viscosity of the compositions on the volume filler content is satisfactorily described by an equation that contains the reduced filler concentration, defined as the ratio of the nominal filler concentration to the limiting concentration at which the adsorption layers on the particles extend throughout the matrix. The thickness of the polymer layer adsorbed on the particles must be determined from the specific exterior particle surface, with allowance for the volume of the polymer in the sorption space of the porous filler.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 3, pp. 478–486, May–June, 1976.     

Effect of fillers on the structure and properties of cured resins

The elastic (modulus of elasticity and equilibrium high-elastic modulus) and thermal (volume coefficients of thermal expansion below and above the glass transition temperature) properties of compositions based on ÉD-5 epoxy resin cured with polyethylenepolyamine have been investigated. Quartz powder and aluminoborosilicate glass powder were employed as fillers at concentrations from 0 to 0.413. The thermal expansion coefficients of the compositions were studied in a dilatometer, in which the specimen is free of mechanical loads. The Young's modulus at 25°C and the equilibrium high-elastic modulus at 125°C of the compositions were determined in the compression regime in an instrument based on the IZV-2 optical length gage. The thermal expansion coefficients of the polymer matrix were calculated with allowance for the elastic properties of the resin and the filler. It is shown that, as the filler concentration increases, the thermal and elastic properties of the resin in the filled system change. This can be interpreted as a change in the properties of the resin as it approaches the surface of the filler particles. Increased interaction between the filler surface and the epoxy resin tends to stiffen the polymer network.Scientific Research Institute of Precision Technology, Moscow. Translated from Mekhanika Polimerov, No. 6, pp. 1018–1022, November–December, 1969.     

Effect of quartz sand filler on the mechanical and thermophysical properties of alkyd and epoxy coatings

The effect of a filler on the mechanical and thermophysical properties of polymer coatings has been investigated. It is shown that quartz sand particles are centers of structure formation in alkyd and epoxy coatings. It has been found that a denser, oriented, and stressed polymer structure, much exceeding the size of the individual macromolecules, is formed around the filler particles. The size of the spheres around the filler particles depends on the nature of the film-former, on the filler surface, and on the filler content. It is postulated that secondary supermolecular structures, and not individual polymer macromolecules, are adsorbed on the surface of the filler particles.Mekhanika Polimerov, Vol. 3, No. 3, pp. 507–510, 1967     

The role of the porous structure of the filler in the reinfo rcement of polymers

Composites consisting of polyethylene and porous fillers with various pore sizes (from 22 to 115 Å) and surface types have been investigated. It is shown that the polymer filling the pores takes part in the deformation processes. The modulus of elasticity of the filled polymers is directly proportional to the filler surface per gram polymer. It is proposed to characterize the activity of the fillers by reference to the slope of the straight lines E-S with the hydrodynamic effect excluded.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 2, pp. 253–258, March–April, 1973.     

Effect of the structure of a polymer matrix and its area of contact with the surface of the filler on the rigidity of a polyethylene composite

The distribution of the orientation of the macromolecules over the wall cross section of a filled polyethylene tube is analyzed. A direct proportionality is established between the degree of orientation (estimated from the shrinkage) and the elastic modulus. The effect of various fillers on the melting and crystallization of low-density polyethylene is considered. For a specified filler concentration the elastic modulus of the composites depends very considerably on the relative area of contact between the polymer matrix and the surface of the filler.Institute of the Mechanics of Polymers, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 3, pp. 387–391, May–June, 1974.     

Temperature reversal of the reinforcing effect of fillers

A previous investigation [4] of the tear strength of filled systems based on SKS-85 butadiene-styrene copolymer over a broad temperature interval revealed a reversal of the reinforcing effect of fillers with a coefficient of thermal expansion different from that of the filled polymer. At Tg the strength of mixtures containing polymer fillers [Kapron (polycaprolactam) and cellophane powder] exceeds that of mixtures containing chalk and carbon black. The temperature reversal effect is attributed to the severe weakening of the adhesion of the polymer to the surface of the filler particles as a result of the concentration of shrinkage stresses in the polymer-filler contact zone. The presence of shrinkage stresses around the filler particles at Tg is qualitatively demonstrated on model systems using a photoelastic technique. Moreover, it is shown that the unbalance, and hence the residual stresses, in filled systems at temperatures below the glass transition temperature of the filled polymer is determined by the difference in the coefficients of thermal expansion.Moscow Technological Institute of the Meat and Dairy Industry. Translated from Mekhanika Polimerov, No. 4, pp. 579–583, July–August, 1969.     

Effect of a filler on the strength properties of thermosets

The effect of a filler on the strength properties of polymers in tension is investigated. The thermostructural stresses that develop in the composite during cure are taken into account. Relations are given for the strength of the filled polymer as a function of the percentage filler content. In the process of analyzing the thermostructural stresses an analytic expression is obtained for the linear expansion coefficient of the composite with allowance for the structural distribution of the components. Calculated values of the strength and thermostructural stresses are presented for composites with different filler contents. The theoretical determination of the strength of filled polymers is compared with the results of experimental investigations of composites based on epoxy resin filled with quartz dust.Leningrad Mechanical Institute. Translated from Mekhanika Polimerov, No. 1, pp. 97–101, January–February, 1973.     

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.     

Study of the effect of the dressing of carbon fibers on the properties of carbon-fiber-reinforced plastics based on polyacetals

Studies are made of the mechanical and friction engineering properties of a copolymer of trioxane-1,3,5 with dioxolan-1,3 reinforced with dressed carbon fibers based on hydrated cellulose. Polyalkyloxysilanes are used as the finishes. The optimum concentrations of the finishes on the fibrous filler are determined. Relations are obtained to describe the dependence of the mechanical properties of carbon-fiber-reinforced plastics on the type of finish and its effect on the condition of the phase boundary between filler and the polymer matrix. The effect of adhesion of the polymer to the fibrous filler on the properties of a randomly reinforced thermoplastic composite is also determined. The dependences of the friction engineering properties of polyacetal-based carbon-plastics on the loading parameters of the friction-loading unit are examined. The material that is developed has high values of strength, elastic modulus, and notch toughness and low values of the friction coefficient and shrinkage. The material can be used as structural and anti-friction elements in rocketry, aviation, and the automobile industry.Ukrainian State Chemical Engineering University, Dnepropetrovsk. Translated from Mekhanika Kompozitnykh Materialov, No. 1, pp. 90–97, January–February, 1997.     

Study of the thermophysical and antifriction properties of polyethylene-based compositions

The results of a study of the effect of the filler properties (thermal conductivity, density, particle shape and size, percentage content) on the thermal conductivity of the composite are presented; the factors responsible for the increase in the thermal conductivity of the polymer are indicated. Formulas are recommended for calculating the thermal conductivity of composites based on polyethlene and various fillers.Institute of Polymer Mechanics, Academy of Sciences of the LatvianSSR, Riga. Translated from Mekhanika Polimerov, No. 2, pp. 259–266, March–April, 1973.     

Effect of aggregation of a dispersed rigid filler on the elastic characteristics of a polymer composite

Conclusions We proposed a method for describing the effective elastic characteristics of a polymer composite with a rigid aggregating filler. An important feature of such a medium is the variable coupling of the inclusion phase in relation to its volume content. A change in the degree of coupling of the filler is accounted for by introducing an additional parameter. We examined a method of determining the coupling parameter from the results of statistical modeling of the geometry of the medium. Using the example of a calcite-HDPE composite, we showed that aggregation has a significant effect on the dependence of the elastic modulus on the volume content of filler; satisfactory agreement was obtained between the theoretical and experimental data.Translated from Mekhanika Kompozitnykh Materialov, No. 1, pp. 14–22, January–February, 1986.     

Change in the structure of polymer matrix of particulate-filled composites: The fractal treatment

An obligatory change (disturbance) in the structure of a polymer matrix is shown to arise upon injecting a disperse filler in it, which is determined by the fractal structure of the skeleton formed by filler particles. The characteristic of this disturbance is obtained in terms of change in the fractal dimension d _f of polymer matrix structure. Tentative estimates show a good correspondence between the values of d _f obtained and experimental data.Translated from Mekhanika Kompozitnykh Materialov, Vol. 40, No. 6, pp. 827–834, November–December, 2004.     

Effect of fibrous filler on the mechanical properties of polystyrene and polymethyl methacrylate in the glassy state

The authors have investigated the effect of introducing fiberglas into polystyrene and polymethyl methacrylate films on the transition temperatures and on the intervening glassy-state temperature intervals within which the polymers possess different physicomechanical properties. The variation in a number of the mechanical characteristics of these polymers has been studied as a function of filler concentration within all the subregions of the glassy state bounded by the transition temperatures obtained. Temperature inversion of the reinforcing action of the fibrous filler within the glassy state has been detected. Attention is drawn to the existence at a given temperature of a large number of filled polymer systems with the same reinforcing effect and the same strength at different contents of the same filler in the same polymer.Mekhanika Polimerov, Vol. 3, No. 3, pp. 517–523, 1967     

Relationship of some mechanical and thermophysical properties of polymer compositions on reduced filler concentration

The dependences of the modulus of elasticity, coefficient of linear expansion, glass transition temperature, and decomposition temperature of epoxide compositions on the concentrations of four fillers of differing physical and chemical natures have been studied. The experimental data were interpreted from the point of view of a lowered mobility of the segments of the polymer molecules as a result of interaction with the filler surface. It was shown to be possible to construct universal curves for each of the studied properties, which were invariant with respect to the nature of the filler.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, Vol. 9, No. 3, pp. 487–491, May–June, 1973.     

Temperature dependence of the strength of adhesive joints based on crystalline polymer adhesives

The temperature dependence of the stripping strength of adhesive joints between steel and dural plates using crystalline polymers as adhesive (mixed polyamide-4, 5, 8 and guttapercha, both unfilled and filled with an inert filler) has been investigated. The temperature-strength curves pass through two local maxima, near the glass transition temperature of the crystalline adhesive and near its melting point. It is shown that the presence of a high-temperature maximum is determined by recrystallization of the polymer in the overstressed zone at the tip of the developing crack. The relationship between temperature and strength in adhesive joints based on crystalline polymer adhesives is very pronounced in both cohesive and adhesive failure. It is shown that the addition of filler reduces the recrystallization stress of guttapercha.Mekhanika Polimerov, Vol. 1, No. 3, pp. 63–67, 1965     

Effect of small additives of oligomer on the viscoelastic properties of carbon fiber plastics

The viscoelastic properties of carbon fiber composites whose phenol-formaldehyde matrix is modified by thermodynamically incompatible isocyanate derivatives have been investigated. Data are given on fiber wetting (Table 11), internal stress (Table 2), viscoelastic properties (Fig. 1), and tensile strength (Fig. 2). The modified composites are strengthened by the addition of 0.5–4% oligomer additive. This process involves the formation of a two-phase structure, in which the additive phase microparticles act as a polymer filler. Due to selective interactions, the intermediate layer formed at the fiber-binder interface leads to changes in the viscoelastic properties and tensile strength of the matrix and improved maintenance characteristics for the material as a whole.Translated from Mekhanika Kompozitnykh Materialov, Vol. 29, No. 4, pp. 440–445, July–August, 1993.     

Elastic and Sorption Characteristics of an Epoxy Binder in a Composite During Its Moistening

Results of an experimental investigation into the elastic and sorption characteristics of a model composite material (CM) — epoxy resin filled with LiF crystals — during its moistening are presented. Properties of the binder in the CM with different filler contents (v _f = 0, 0.05, 0.11, 0.23, 0.28, 0.33, 0.38, and 0.46) were evaluated indirectly by using known micromechanical models of CMs. It was revealed that, for the CM in a conditionally initial state, the elastic modulus of the binder in it and the filler microstrain (change in the interplanar distance in the crystals, measured by the X-ray method) as functions of filler content had the same character. The elastic modulus of the binder in the CM with a low filler content was equal to that for the binder in a block; the elastic modulus of the binder in the CM decreased with increasing filler content. The maximum (corresponding to water saturation of the CM) stresses in the binder and the filler microstresses as functions of filler content were of the same character. Moreover, the absolute values of maximum stresses in the binder and of filler microstresses coincided for high and low contents of the filler. At v _f = 0.2–0. 3, the filler microstrains exceeded the stresses in the binder. The effect of moisture on the epoxy binder in the CM with a high filler content was not entirely reversible: the elastic characteristics of the binder increased, the diffusivity decreased, and the ultimate water content increased after a moistening-drying cycle.__________Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 4, pp. 499–511, July–August, 2005.