Search

Structural changes in polylactide/polybutylene terephthalate (PLA/PBT) and glycol‐modified polyethylene terephthalate/polybutylene terephthalate (PET‐G/PBT) polymer blends at a pressure of 1 GPa and room temperature in combination with shear deformation are investigated. High pressure torsion (HPT) is chosen as the compatibilization technique. Based on solid‐state NMR data, it is found that the compatibility of immiscible polymers is significantly improved under high pressure conditions in combination with shear deformation. It is assumed that the thickness of the deformed polymer layers decreases to the thickness of the interphase and it can be a fully interphase material. [ABSTRACT FROM AUTHOR]

In this work, by the example of the system of linear low-density polyethylene-multi-walled carbon nanotubes (LLDPE/CNTs), specific features of the nanocomposite structure modified by severe plastic deformation (SPD) are studied. The effect of SPD on the mechanical properties and electrical conductivity is analyzed. It is shown that SPD leads to destruction of CNTs aggregates and more homogeneous their distribution. CNTs formed structure is characterized by the presence of large (200-300 nm) aggregates of CNTs and small (, INTRODUCTION Carbon nanotubes (CNTs) are an advanced reinforcement material in polymer composites targeted at a wide range of practical applications due to their superior mechanical, thermal and electrical properties [1,2]. [...]

Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a piezoelectric semi-crystalline polymer whose electro-mechanical properties may be modulated via strain-induced α → β phase transition and the incorporation of polarized inorganic particles. The present work focuses on the constitutive representation of PVDF-based piezo-composites developed within the continuum-based micromechanical framework and considering the combined effects of particle reinforcement, α → β phase transition, and debonding along the interface between the PVDF matrix and the particles under increasing deformation. The micromechanics-based model is applied to available experimental data of PVDF filled with various concentrations of barium titanate (BaTiO3) particles. After its identification and predictability verification, the model is used to provide a better understanding of the separate and synergistic effects of BaTiO3 particle reinforcement and the micromechanical deformation processes on the electro-mechanical properties of PVDF-based piezo-composites. [ABSTRACT FROM AUTHOR]

The combination of high strength and toughness is always the goal of high‐performance polymer materials for industrial use. This study addresses the potentialities of a solid state equal‐channel multiple‐angular extrusion (ECMAE) in production of polylactide (PLA) with simultaneous improvement in toughness, strength, and thermal stability. Chain extender Joncryl was used to form PLA with different chain length and morphology (linear or branched PLA). It is demonstrated that simple shear deformation implemented in ECMAE results in formation of an orientation order, an increase in the degree of crystallinity, and the creation of α crystals with an increased degree of perfection. The value of the effects achieved depends on the type of PLA morphology. The best result is observed in the case of linear PLA. ECMAE‐modified linear PLA possess the better combination of strength, modulus, and ductility than the branched one. Compared with neat linear PLA, ECMAE‐modified linear PLA shows 12%, 26%, 217%, and 40% increase in tensile strength, Young's modulus, strain at break and impact strength, respectively. Additionally, the storage modulus shows an improved thermal stability of ECMAE‐modified PLA. [ABSTRACT FROM AUTHOR]

The effect of technological conditions of the process and zirconia (ZrO 2 ) nanoparticles on the properties of fine-fibrous filter materials (FMs) obtained by matrix polymer extraction from a microfibrillar composite formed using the material extrusion-based additive manufacturing method from a polypropylene (PP)/copolyamide blend is studied. Different processing schemes were used for obtaining filaments for material extrusion: scheme I-the use of a single-screw extruder at the stage of compounding; scheme II-the use of a single-screw extruder at the stage of compounding and orientational stretching in the course of strand formation; scheme III-the use of a twin-screw extruder at the stage of compounding, scheme IV-the addition of ZrO 2 nanoparticles and use of a twin-screw extruder. It has been shown the possibility of reducing the diameters of the formed in situ PP microfibrils by using the twin-screw extruder, as well as additional orientation drawing. The introduction into the melt of ZrO 2 nanoparticles provides further improvement of the microstructure-the average diameter of the microfibrils is reduced by 1.4 times compared with the initial blend. Developed FMs are characterized by high efficiency of air purification from solid particles with a size of 0.3 μm. At the same time, the use of nanoadditives is the most effective-a two-layer FM with nanoparticles provides cleaning efficiency at the level of four- to six-layer materials without filler., Competing Interests: No competing financial interests exist., (Copyright 2021, Mary Ann Liebert, Inc., publishers.)