Przeglądaj {{ collection }} wg Autor "Włodarska, Magdalena"

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Conductivity in cured epoxy resins containing a biphenyl unit
(Wydawnictwo Politechniki Łódzkiej, 2010) Włodarska, Magdalena; Izdebski, Marek; Bąk, Grzegorz; Mossety-Leszczak, Beata; Galina, Henryk
Conductivity of two epoxy matrices based on the same monomer was compared. The epoxy monomer had symmetric structure and contained the biphenyl group which induced additional phase transitions in the pure material. Two amines responsible for different curing mechanisms were used to prepare the matrices. Wide ohmic regions were observed in both materials but quite high activation energy results in quick drop of conductivity at low temperatures and the materials can be treated as good isolators below 100°C. The obtained results are comparable with traditional epoxy resins.
Curing conditions and dielectric observation of an epoxy system based on Epidian 6
(Wydawnictwo Politechniki Łódzkiej, 2013) Włodarska, Magdalena; Skurpel, Bartosz
In this work the dielectric properties and curing conditions of a selected epoxy resin are presented. The curing system consists of Epidian 6 with DDM amine. In the first step, optimal curing conditions were determined for different amine concentrations in the mixture. It is shown on a diagram, how the properties of the cured matrix depend on the percentage concentration of the curing agent. Dielectric measurements were carried out for two concentrations – 10% and 16% – both in the course of curing and for the final product. Significant differences in the dielectric responses were observed as a result of different conversion levels in the obtained resins.
Curing process and the curing product of a nematic epoxy resin containing ester groups
(Wydawnictwo Politechniki Łódzkiej, 2007) Włodarska, Magdalena; Mossety-Leszczak, Beata; Bąk, Grzegorz; Galina, Henryk
Curing process and the product of curing of one liquid crystalline epoxy monomer with a standard omine were examined. The reactions were monitored by DSC measurement and dielectric spectroscopy. Progress of curing of the examined mixture at different temperatures was shown. Influence of curing conditions on the final product was discussed and compared with other similar systems. DSC thermograms of the curing product were also analysed.
Electric conductivity in epoxy matrix with nanoparticles
(Wydawnictwo Politechniki Łódzkiej, 2012) Włodarska, Magdalena; Partyka, Michał; Bąk, Grzegorz; Mossety-Leszczak, Beata; Galina, Henryk; Florjańczyk, Zbigniew; Łokaj, Krzysztof
This work presents results of DC conductivity measurements obtained for epoxy matrices with different concentration of the nanofiller. In the first step, optimal curing conditions were determined - which turned out to be similar to those established for a plain epoxy matrix. In order to confirm stability of the matrix, measurements of the current-time dependency were made, which clearly show both the chemical and electric stabilization at the given temperature. All the obtained materials appeared to be good insulators with high activation energy. It was observed that the activation energy decreases slightly with increasing concentration of the nanofiller.