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Khimenko L.L.,Institute of Polymer Materials | Rybakov A.P.,Polytechnic University of Mozambique | Rybakov N.A.,Polytechnic University of Mozambique | Kozlovc A.N.,Perm State Agricultural Academy
Journal of Applied Mechanics and Technical Physics

Results of experimental measurements of Young’s modulus, burning rate, and specific heat of condensed high-energy polymer compositions (solid propellants) subjected to microwave radiation are reported. Experimental equipment and arrangement of experiments are described; the results obtained are analyzed. © Pleiades Publishing, Ltd., 2014. Source

Rybnicek J.,Czech Technical University | Rybnicek J.,R.O.S.A. | Lach R.,Institute of Polymer Materials | Lach R.,Martin Luther University of Halle Wittenberg | And 7 more authors.
Key Engineering Materials

Instrumented scratch test was carried out to determine the scratch resistance of polyamide 6 (PA 6) nanocomposites, where two kinds of nanofillers were tested, both based on silicates: montmorillonite (MMT) and halloysite nanotubes (HNT). In this work the influence of the sliding velocity, normal applied load and time-dependent recovery on the penetration depth and scratch hardness was investigated. Optical microscopy was utilized to determine the width of the scratch grooves and scanning electron microscopy revealed the damage features of the scratched surfaces. Both MNT and HNT nanofillers improve the scratch resistance of PA 6 considerably. As a result of the microstructure of the polymer nanocomposites MNT gives PA 6 a better residual depth resistance while HNT raises its scratch hardness (i.e. reduces the scratch width). Furthermore, via different depth-sensing indentation techniques in the nano-, micro- and macro-range of loading the short-term performance (Martens hardness and indentation modulus) and the time-dependent creep behavior have been analyzed for PA 6 and the PA 6 nanocomposites as a function of applied load and temperature. Additionally, WAXS (wide-angle X-ray scattering) and DSC (differential scanning calorimetry) measurements to establish morphology-property relationships of the materials investigated considering the skin-core structure of the injection molded samples were made. © (2014) Trans Tech Publications. Source

Rybnicek J.,Czech Technical University | Lach R.,Institute of Polymer Materials | Lach R.,Vienna University of Technology | Lach R.,Martin Luther University of Halle Wittenberg | And 6 more authors.

PC/ABS/PMMA blends with a varied content of PMMA were studied. TEM microscopy was employed to reveal the individual phases. Uniaxial tensile testing and instrumented macro-hardness indentation were carried out to quantify the hardness, indentation modulus, elastic and plastic deformation work during indentation, yield strain and stress values. The data was correlated with the morphology. In case PMMA is the minor phase, it tends to locate on the PC/SAN interface; whereas in case of being the major one, SAN plays the role of compatibilizer and encapsulates the PC particles. Good compatibility of the blends was confirmed by the results of mechanical testing, which revealed strain-controlled plasticity. Source

Ryba J.,Institute of Polymer Materials | Horbanova L.,Institute of Polymer Materials | Ujhelyiova A.,Institute of Polymer Materials | Michlik P.,Research Institute for Man Made Fibers
Vlakna a Textil

This work was aimed to study the properties of polypropylene (PP) fibers modified by inorganic additives, assigned for improve the end-used properties of construction composites based on silica. Modification of fibers by addition of sufficient additive insure more intense anchoring of polypropylene fibers in cement matrix, what leads to expressive improve of functional of PP fibers in relation to transmission and absorption of deformation energy at mould and load silica composites. Impact of inorganic additives on the thermomechanical and mechanical properties of fibers, and the compatibility of individual components are investigated. Thermomechanical properties of modified polypropylene fibers were evaluated by thermomechanical analysis (TMA). From obtained dependences, temperature of fiber shrinkage and total shrinkage of fibers containing inorganic additives were found to be lower than at specimens of standard fiber. Mechanical properties of fibers were study by investigation of characteristics as strength and Young's module of fibers with and without stabilization. Source

Kristofic M.,Institute of Polymer Materials | Ujhelyiova A.,Institute of Polymer Materials
Fibres and Textiles in Eastern Europe

Blending polymers is widely used for the preparation of new materials. The disadvantage of this application is that the polymer components are usually not compatible and the preparation of blends with suitable (mainly processing and mechanical) properties is not satisfactory. The use of a third compound, called a compatibiliser, is an effective way to ameliorate the end-use properties of the blend. Compatibilisers based on grafted or block copolymers are often used. The present contribution deals with the compatibilisation of polypropylene/polyamide blends with compatibilisers based on grafted or block polyolefines. Source

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