Yevgen Mamunya

Polymer blends filled with carbon black: structure and electrical properties

Morphology and electrical conductivity of polymer blends based on polypropylene, polyethylene, polyoxymethylene, polyamide 12, copolymer ABS filled with carbon black (CB) were studied. When filler is introduced in polymer blend, three cases of filler spatial distribution can be obtained. CB can be distributed randomly within polymer matrix, can be situated in one of the polymer components or can be localized on the boundary of the polymer components. The existence of different cases of filled blends structure is defined by following reasons: thermodynamic factors (relationship between interface surface tensions of polymer-filler γ pf and polymer-polymer surface tension γ pp ); kinetic factors (relationship between viscosities of polymer components); processing factors (methods of the filler introduction in the complex polymer matrix, which can enhance or depress the influence of thermodynamic and kinetic factors).

Structural Peculiarities of Ion-Conductive Organic-Inorganic Polymer Composites Based on Aliphatic Epoxy Resin and Salt of Lithium Perchlorate

The article is concerned with hybrid amorphous polymers synthesized basing on epoxy oligomer of diglycide aliphatic ester of polyethylene glycol that was cured by polyethylene polyamine and lithium perchlorate salt. Structural peculiarities of organic-inorganic polymer composites were studied by differential scanning calorimetry, wide-angle X-ray spectra, infrared spectroscopic, scanning electron microscopy, elemental analysis, and transmission and reflective optical microscopy. On the one hand, the results showed that the introduction of LiClO4 salt into epoxy polymer leads to formation of the coordinative metal-polymer complexes of donor-acceptor type between central Li+ ion and ligand. On the other hand, the appearance of amorphous microinclusions, probably of inorganic nature, was also found.

Relaxation processes in hybrid organic-inorganic polymer nanosystems polymerized in situ

The relaxation processes of hybrid organic-inorganic polymer nanosystems (OIS) synthesized by joint polymerization of organic and inorganic components were studied using methods of differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and broadband dielectric relaxation spectroscopy (DRS). The organic component was a mixture of two products: high-molecular-weight macrodiisocyanate (MDI) with low reactivity and low-molecular-weight isocyanate-containing modifier poly(isocyanate) (PIC) with high reactivity. Sodium silicate (SS) was used as inorganic component. The structures of the OIS obtained were in the form of hybrids with covalently connected building blocks and interpenetrating networks: weakly cross-linked network MDI/SS and highly cross-linked network PIC/SS. Depending on the MDI/PIC ratio, one of the networks was prevailing and created a continuous structure with domains of second network.PACS61.25.hk; 82.35.Lr; 64.70.pj

The anomalous behavior of physical-chemical parameters during polymerization of organic-inorganic polymer systems based on reactive oligomers

Abstract Dependencies of physical-chemical characteristics on structure development during polymerization of organic-inorganic systems (OISs) have been investigated. The non-monotonic behavior of the physical parameters has been found. This effect was explained by complicated structure of OISs, which consists of two interpenetrating hybrid organic-inorganic networks, which are characterized by different rate of the structure formation.

Structure and Electrical/Dielectric Properties of Ion-Conductive Polymer Composites Based on Aliphatic Epoxy Resin and Lithium Perchlorate Salt

Nowadays, one of the most important research directions in development and creation of functional polymeric materials is a search of new solid electroactive polymers with high ionic conductivity at elevated temperatures. Particularly, the widening range of materials, which can be used for this purpose, is relevant. The present work is concerned with hybrid amorphous polymers synthesized basing on epoxy oligomer of diglycide aliphatic ester of polyethylene glycol (DEG-1) that was cured by polyethylene polyamine and lithium perchlorate salt. Structural peculiarities of the synthesized polymer composites were studied by differential scanning calorimetry, wide-angle X-ray spectra, infrared spectroscopic, scanning electron microscopy, elemental analysis, and transmission and reflective optical microscopy. The presence of ether oxygen in DEG-1 macromolecules provides a transfer mechanism of the lithium cations with the ether oxygen similar to polyethylene oxide. Thus, the obtained hybrid polymers have high values of ionic conductivity σ′ (approximately 10−3 S/cm) and permittivity e′ (6 × 105) at elevated temperatures (200°С). On the one hand, the results showed that the introduction of LiClO4 salt into epoxy polymer leads to formation of the coordinative metal-polymer complexes of donor-acceptor type between central Li+ ion and ligand. On the other hand, the appearance of amorphous microinclusions, probably of inorganic nature was also found.

A modern approach in wood waste management: composites based on a novel copolyamide as matrix

In this study, the obtaining of some composite materials using wood chips as filler and a modified polyamidic polymer as thermoplastic matrix is presented. Characterization was carried out on composite samples by analysis of morphology, mechanical properties and thermal behaviour. It was observed that the tensile strength of composites decreased significantly with the increasing wood chips content. Still, even the bending strength is decreasing; it remains 2-8 times higher than that for the composites based on polyolefinic matrices. The thermal stability of the obtained composite materials is higher to that of the initial wood component.