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     

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.     

聚合物混合质量的智能控制

聚合物与填料的混合质量，直接影响聚合物成品质量，混合质量的在线控制并优化控制参数已成为保证聚合物成品质量的关键。本文首先建立基于填料颗粒面积与位置分布为判断指标的填料等级识别模型，并借助计算机与数字图形处理技术获取填料混合质量的信息，在此基础上建立了聚合物混合参数的优化控制模型，仿真检验的结果表明，模型是合理的，且与投入使用的同类仪器相比具有更满意的结果。     

Movement of low-molecular-weight polyisobutylene in capillaries at large rates of deformation

Conclusions 1. A decrease in flow rate is observed upon increase in the pressure drop between the ends of a capillary at large pressure drops in the unstable flow region.2. It has been ascertained that the radial distribution of mean lengthwise velocity has an inflection close to the capillary wall.3. Wall slippage of the polymer has been observed and measured.4. A correlation of velocity pulsations in the channel with disturbances in the jet has been established.Institute of Problems of Mechanics, Academy of Sciences of the USSR, Moscow. Moscow Power Institute. Translated from Mekhanika Polimerov, No. 4, pp. 724–730, July–August, 1976.     

Energy investigation of the softening of siloxane rubbers during deformation

The softening of filled siloxane rubbers in tension is investigated from the energy standpoint. It is shown that during extension the starting structure of the rubber is converted into a new, energetically equivalent one. It is concluded that the most probable softening mechanism for filled rubbers is a rearrangement of the macromolecular chains at the surface of the filler particles as a result of slippage. Softening anisotropy of the siloxane rubbers is observed.Institute of Hetero-Organic Compounds, Academy of Sciences of the USSR, Moscow. Synthetic Materials Council, Presidium of the Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 3, pp. 387–392, May–June, 1975.     

On the fracture mechanism in filled rubbers

Possible fracture mechanisms in filled rubbers are examined in the light of the adhesion theory of elastomer reinforcement. The cases of rubbers containing inactive fillers, when the crack grows along the elastomer-filler boundary, and rubbers containing active fillers, when the crack propagates through the polymer, are considered. The effect of the presence of chains of filler particles on the fracture mechanism is examined.Lomonosov Moscow Institute of Fine Chemical Technology. Translated from Mekhanika Polimerov, Vol. 5, No. 1, pp. 127–133, January–February, 1969.     

Effect of the nature of the filler surface on the properties of phenol-formaldehyde molding powders

The physicomechanical properties and microstructure of phenolic molding powders containing fillers with different surface energies have been investigated. It has been found that an increase in filler surface energy leads to an increase in the density of the resin around the filler particles and hence to an improvement in the physicomechanical properties of the molding powder. A parallel investigation of a molding powder containing a lubricant shows that adsorption of the lubricant on the filler surface reduces the density of the resin, which is accompanied by a deterioration in the properties of the material.Scientific-Research Institute of Precision Engineering Moscow. Translated from Mekhanika Polimerov, Vol. 4, No. 4, pp. 677–681, July–August, 1968.     

Effect of fillers on the structure and properties of cured resins

It is shown for the first time that the increased strength of filled plastics is associated with an increase of the internal pressure in the resin determined by the nature of the filler surface and the curing conditions.For communication 1, see [1].Moscow. Translated from Mekhanika Polimerov, No. 1, pp. 54–58, January–February, 1970.     

Effect of fillers and solvents on the properties of polystyrene coatings

The mechanism of coating formation from solutions of atactic polystyrene in xylene and carbon tetrachloride has been investigated. It has been established that, as the filler content increases, in coatings formed from polystyrene solutions containing an evaporating solvent the growth of the internal stresses and the thermophysical characteristics is characterized by similarity of slope, as distinct from the case of coatings obtained from systems containing a polymerizing solvent. It is shown that the nature of the solvent has an important effect on the character of the interaction at the polymer—filler interface and on the structure and properties of the coatings.Kucherenko Central Scientific-Research Institute of Structural Design. Institute of Physical Chemistry, AS USSR, Moscow. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 1127–1129, November–December, 1968.     

Effect of quartz concentration and dispersity on the physico-mechanical properties of perchlorovinyl film

The structure of perchlorovinyl film is not affected by the addition of finely ground quartz. The modulus of elasticity and coefficient of thermal expansion of the film change additively with increase in filler concentration and do not depend on filler dispersity. The filler reduces the strength of the film and the elongation at break.Institute of Physical Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 6, pp. 1023–1027, November–December, 1969.     

Selection of the optimal structure of chopped-strand composites

A mechanical model of the interaction between the reinforcing elements and the polymer matrix is proposed for glass-reinforced plastics with a random distribution of the reinforcing elements. On the basis of this model, a theoretical relation is obtained for the variation of the strength utilization factor with increase in the fiber length-to-diameter ratio, with allowance for the glass-to-resin ratio and the elastic characteristics of the components. The theoretical calculations are found to be in satisfactory agreement with the experimental data.All-Union Scientific-Research Institute of Glass-Reinforced Plastics and Glass Fiber, Moscow Region. Moscow Bauman Higher Technical College. Translated from Mekhanika Polimerov, Vol. 5, No. 2, pp. 288–297, March–April, 1969.     

Effect of polymer molecular weight on its reaction with nonporous and porous fillers

The effect of polymer molecular weight (using polyethylene and polyisobutylene) on the formation of polymer contact with the surface of porous and nonporous fillers has been studied. It has been shown that the extent of coating of a nonporous surface by polymer does not depend on polymer molecular weight, but the extent of coating of a porous surface is larger, the lower the molecular weight of the polymer; this is explained by a selective adsorption of macromolecules of lower molecular weight on the porous filler from the polymer melt.     

On the theory of biaxial orientation of amorphous polymers

The macromolecule orientation distribution function for biaxial orientation is calculated on the basis of a network model of a linear amorphous polymer. The dependence of the distribution function on the biaxial stretch ratio, orientation temperature, and certain other factors is investigated. A relation is established between the distribution function and the experimentally observed birefringence. The birefringence of biaxially oriented polymethyl methacrylate is measured in relation to the degree of deformation. The experimental data are compared with theory.Moscow Lenin State Pedagogical Institute, Problem Laboratory of Polymer Physics. Translated from Mekhanika Polimerov, No. 5, pp. 771–779, September–October, 1970.     

Application of the reduced concentration principle to filled polymers

An investigation has been made into the applicability of the reduced concentration principle to composites based on a partially crystalline polymer — low-density polyethylene — with 13 mineral fillers of different chemical composition, particle size, and porosity. It is shown that over the entire accessible interval of filler load factors the composites investigated obey the law of corresponding states. It is suggested that the deviation of the generalized dependence of the modulus of elasticity from the analogous dependence obtained for amorphous network polymers is associated with a decrease in the crystallinity of the polymer matrix with increase in filler concentration.     

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.     

Plane stress finite element analysis of filler reinforced polymers

The characteristics of polymers such as force-deformation behaviour, strength, fatigue and wear resistance, can be tailored by embedding it with filler particles. The influence of the fillers on the material behaviour significantly depends on the size and geometric form of the filler aggregates, which vary under mechanical loading. The concept of super element is used to model filler particles. This is now coupled with the polymer matrix to generate a finite element model of filler reinforced polymers. In this work, we investigate the effect of filler geometry and volume fraction of fillers on the overall stiffness of the filler reinforced polymer. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Effect of a dispersed filler on the modulus of elasticity of composites in the glassy state

An expression is proposed for predicting the reinforcement of composites by a dispersed filler in both the rubbery and glassy states with allowance for the internal thermal stresses in the polymer matrix. It is shown that by varying the plasticizer concentration in composites based on polyvinyl chloride it is possible to regulate the thermal stresses in the polymer matrix. The time-stress and time-concentration superposition principles are shown to be applicable to the dependence of the relative modulus of elasticity on filler concentration for glassy composites.     

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 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.