E. Plume

Mechanical properties of polyester polymer-concrete

The properties of a polymer-concrete composed of polyester matrix and locally available rock aggregate are investigated. The formula of the concrete is found by an experimental-calculation approach in such a way as to attain a closer packing of the aggregate particles on the one hand, and to ensure the needed processing characteristics (placeability) of the mix on the other. It is shown experimentally that the material obtained has a rather high compression strength. Under prolonged compression loads, the polymer-concrete exhibits a noticeable creep behavior with a linear relation between the creep strains and stresses. After the action of half the ultimate load over 3000 h, the total strains exceed the instantaneous ones by 2.0 to 2.2 times. The accumulation of irreversible strains is also observed; however, their contribution to the total strain is small. It is found that the stress-strain relation can be represented by the equation of linear hereditary creep theory.

Elastic and Thermophysical Properties of Poly(Vinyl Chloride) and Chlorinated Polyethylene Blends

The results of experimental and theoretical investigations of elastic and thermophysical properties of poly(vinyl chloride) (PVC) and chlorinated polyethylene (CPE) blends are presented. Eight types of specimens with different ratios of weight contents of PVC and CPE (PVC/CPE = 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100) were tested. The effect of blend composition on the elastic constants (tensile and shear modulus) is discussed. The data on the thermal conductivity, thermal diffusivity, and heat capacity of the blends investigated are also presented.

Mechanical properties of a rigid polyurethane/montmorillonite composite prepared by using a biopolyol

The preparation of specimens from a rigid polyurethane containing montmorillonite (MMT) particles as a filler is described. The specimens were fabricated employing a biopolyol synthesized from rapeseed oil. The investigation of their structure was performed by using the X-ray diffraction analysis. The thermomechanical properties of the specimens were determined by means of a dynamic mechanical analysis at temperatures varying from 20 to 160°C. Experimental data on the influence of MMT additions on the mechanical properties (hardness, strength, elastic modulus, ultimate elongation, and creep) of the composite are obtained. A theoretical analysis of elastic properties of the composite is carried out by using the Mori–Tanaka theory of an equivalent medium. The calculation results are compared with experimental data.

Thermal and elastic properties of poly(vinyl chloride) (PVC) + chlorinated polyethylene (CPE) blends

Abstract. Eight types of PVC + CPE blends with different weight ratios (PVC/CPE = 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100) are tested. Data on the heat conductivity, thermal diffusivity, and heat capacity of the blends investigated are reported. Primary attention is paid to the structural approach for effective elastic constants: bulk, shear, and Youngs modulae. The blends are considered as random mixtures of two isotropic constituents. It is found that the elastic moduli may be well represented by the Kerner and Budiansky equations.

Elastic properties of a polyurethane/montmorillonite nanocomposite

A variant for determining the elastic characteristics of composites containing platelike filler particles is considered. The elastic properties of a nanocomposite based on a rigid polyurethane and organically modified montmorillonite are analyzed. Data on the influence of volume fraction of the filler and of anisometry (aspect ratio) and orientation of the montmorillonite particles on the elastic constants of the nanocomposite are reported.

Water Resistance of Polyester Polymer Concrete

The results of experimental investigation of polyester resin and polymer concrete at a long-term (four-year) exposure to water and air with 98% RH are presented. The polymer concrete was composed of a polyester resin as a binder, lime flour, quartz sand, and granite chips. The resin content in concrete was 20 wt.%. The features of sorption properties of the materials investigated are discussed. Data on the water effect on the compressive strength in short-term loading are reported. The creep tests of virgin polymer-concrete specimens were carried out for five years at different stress levels from 0.11 to 0.44 of the short-term prismatic strength. The effect of moisture on the creep behavior was also studied.

Prediction of the Stress-Relaxation Behavior of Thermoshrinkable Radiation-Modified Polymer Materials

The results of investigating nonirradiated and gamma-irradiated (to an absorbed dose of 150 kGy) specimens of an ethylene-octene copolymer are presented. The thermal properties (melting endotherm and crystallization exotherm) are determined by the method of differential scanning calorimetry. The behavior of the material in short-term tension is discussed. The primary attention is given to the temperature-time dependence of the mechanical properties of the materials under creep and stress relaxation. The long-term stress relaxation is predicted from short-term creep tests at elevated temperatures using the temperature-time correspondence principle. The results obtained indicate that the material investigated may be used for thermoshrinkable polymer products with long-term serviceability.

Elastic Properties of a Polymer/Silicate Composite with Platelike Multilayer Filler Particles

A variant of stepwise calculations of the elastic constants of a composite containing platelike multilayer filler particles is presented. First, the effective characteristics of unexfoliated particles in the form of multilayer stacks with interlaminar galleries enlarged as a result of intercalation of polymer are determined. Then, the independent elastic constants of the transversely isotropic representative structural elements of a composite in which multilayer particles are located strictly coplanarly, i.e., parallel to each other, are calculated. Finally, the elastic constants of a composite with randomly oriented particles are obtained by using the method of orientational averaging. Data on the influence of the number of monolayers in the unexfoliated silicate filler particles on their reinforcing efficiency are reported and discussed.