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Dive into the research topics where Magdalena Maciejewska is active.

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Featured researches published by Magdalena Maciejewska.


Journal of Chromatography A | 2012

Surface properties of calcium and magnesium oxide nanopowders grafted with unsaturated carboxylic acids studied with inverse gas chromatography.

Magdalena Maciejewska; Alicja Krzywania-Kaliszewska; Marian Zaborski

Inverse gas chromatography (IGC) was applied at infinite dilution to evaluate the surface properties of calcium and magnesium oxide nanoparticles and the effect of surface grafted unsaturated carboxylic acid on the nanopowder donor-acceptor characteristics. The dispersive components (γ(s)(D)) of the free energy of the nanopowders were determined by Grays method, whereas their tendency to undergo specific interactions was estimated based on the electron donor-acceptor approach presented by Papirer. The calcium and magnesium oxide nanoparticles exhibited high surface energies (79 mJ/m² and 74 mJ/m², respectively). Modification of nanopowders with unsaturated carboxylic acids decreased their specific adsorption energy. The lowest value of γ(s)(D) was determined for nanopowders grafted with undecylenic acid, approximately 55 mJ/m². The specific interactions were characterised by the molar free energy (ΔG(A)(SP)) and molar enthalpy (ΔH(A)(SP)) of adsorption as well as the donor and acceptor interaction parameters (K(A), K(D)).


Journal of Composites | 2013

Ionic Liquids Applied to Improve the Dispersion of Coagent Particles in an Elastomer

Magdalena Maciejewska; Marian Zaborski

The aim of this work was to study the activity of several ionic liquids (alkylimidazolium salts) that are used to improve the dispersion of coagent particles in peroxide-cross-linked hydrogenated acrylonitrile butadiene elastomer (HNBR). Hydrotalcite grafted with monoallyl maleate was applied as a coagent for the HNBR vulcanization. In this paper, we discuss the effect of the ionic liquids (alkylimidazolium salts) with respect to their anion (bromide, chloride, tetrafluoroborate, and hexafluorophosphate) and the length of alkyl chain in the cation (allyl-, ethyl-, butyl-, hexyl-, and octyl-) on the vulcanization kinetics of rubber compounds. The influence of ionic liquids on the cross-link density, the mechanical properties of the vulcanizates, and their resistance to weather ageing were also studied. Alkylimidazolium salts seem to improve the dispersion of the coagent particles and to be active in the cross-linking of HNBR with peroxide. The type of ionic liquid considerably influences the activity of the coagent particles toward the HNBR. The application of ionic liquids increases the cross-link density of the vulcanizates and improves their resistance to weather aging.


Materials Science Forum | 2012

The Influence of Nanostructured Metal Oxides and Unsaturated Acids on Peroxide Cross-Linking of Ethylene-Octene Rubber

Martyna Pingot; Tomasz Pingot; Magdalena Maciejewska; Marian Zaborski

This paper deals with blends of ethylene-octene rubber (POE) with nanostructured metal oxides: magnesium oxide (MgO), calcium oxide (CaO), zinc oxide (ZnO) and unsaturated acids: itaconic acid (IA), sorbic acid (SA) and crotonic acid (CA), as co-agents. Dicumyl peroxide (DCP) was used as a vulcanizing agent. Elastomer composites were prepared in Brabender measuring mixer N50. Rheometric properties of rubber mixes and crosslink density of vulcanizates were measured. Mechanical properties of the samples were also investigated. Dispersion degree of coagents in elastomer matrix was studied by SEM images. Cross-link density analysis revealed that POE vulcanizates contained both ionic bonds and covalent bonds. The results showed that the nanostructured metal oxides and unsaturated acids used as co-agents can greatly improve the modulus at 100% of elongation and tensile strength of the vulcanizates.


Polish Journal of Chemical Technology | 2014

Modified and Unmodified Zinc Oxide as Coagent in Elastomer Compounds

Agnieszka Kołodziejczak-Radzimska; Teofil Jesionowski; Magdalena Maciejewska; Marian Zaborski

Abstract The aim of this work was to study the activity of unmodified and modified ZnO in the peroxide crosslinking of hydrogenated acrylonitrile-butadiene elastomer (HNBR) and ethylene-propylene copolymer (EPM). In the first step, zinc oxide was obtained by emulsion precipitation. Maleic acid was introduced onto the surface of ZnO using an in situ method. The unmodified and modified zinc oxide was characterized using dispersive and morphological analysis, BET surface area analysis, and elemental, spectroscopic and thermal analysis. In the second stage of the research, the ZnO/MA systems were incorporated into the structure of elastomer compounds improving the kinetic and mechanical properties of vulcanizates. The proposed modification method had a favorable effect on the physicochemical properties of the zinc oxide and on the kinetic and mechanical properties of the vulcanizates. This study demonstrated that modification of zinc oxide by maleic acid is a promising technique.


Soft Materials | 2013

Nanosized Mineral Oxides Modified with Unsaturated Acids as Coagents for Peroxide Vulcanization

Magdalena Maciejewska; Marian Zaborski; Alicja Krzywania-Kaliszewska

The activity of nanosized calcium and magnesium oxides as coagents in peroxide vulcanization of hydrogenated acrylonitrile- butadiene elastomer (HNBR) was studied. The surface of mineral oxides was modified with unsaturated acids (allylmalonic, citronellic, and sorbic) to ensure the activity in elastomer vulcanization. The effect of coagents on the cross-linking density and mechanical properties of vulcanizates was discussed. Modified nanosized calcium and magnesium oxide seemed to be active as coagents and caused the formation of additional labile ionic clusters in elastomer networks. Their application decreased the optimal vulcanization time of rubber compounds and improved the cross-link density and tensile strength of vulcanizates, which is very important from technological point of view.


Industrial & Engineering Chemistry Research | 2010

Ionic Liquids as Vulcanization Accelerators

Juliusz Pernak; Filip Walkiewicz; Magdalena Maciejewska; Marian Zaborski


Industrial & Engineering Chemistry Research | 2013

Novel Ionic Liquids as Accelerators for the Sulfur Vulcanization of Butadiene–Styrene Elastomer Composites

Magdalena Maciejewska; Filip Walkiewicz; Marian Zaborski


Comptes Rendus Chimie | 2012

Characterisation of the antioxidant acitivity of riboflavin in an elastomeric composite

Anna Masek; Ewa Chrzescijanska; Marian Zaborski; Magdalena Maciejewska


Comptes Rendus Chimie | 2012

Mineral oxides and layered minerals in combination with itaconic acid as coagents for peroxide crosslinking of hydrogenated acrylonitrile-butadiene elastomer

Magdalena Maciejewska; Marian Zaborski; Alicja Krzywania-Kaliszewska


American Journal of Materials Science | 2012

Hydrotalcite/unsaturated Carboxylic Acid Systems as Coagents in Ethylene-Propylene Copolymer Vulcanization

Magdalena Maciejewska; Alicja Krzywania-Kaliszewska; Marian Zaborski

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Filip Walkiewicz

Poznań University of Technology

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Juliusz Pernak

Poznań University of Technology

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Teofil Jesionowski

Poznań University of Technology

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