Constant Magnetic Field as a Tool for Modification of the Properties of Polymer Composites with Silicone Rubber Matrix.

The aim of this research was to obtain new polymer composites with a silicone rubber matrix, having favorable mechanical and functional properties. They contained admixtures in the amount of 10% by weight of expanded graphite (EG) or birch bark (BB). Additionally, some composites contained magnetic particles in the form of carbonyl iron in the amount of 20% by weight. The tensile strength, water absorption, frost resistance, surface contact angle, and free surface energy were examined. Microscopic images were taken using the SEM method and the content of some elements in selected microareas was determined using the EDXS method. In the study, a constant magnetic field with magnetic induction B was used, by means of which the properties and structure of polymer composites were modified. Scientific research in the field of polymers is the driving force behind the progress of civilization. Smart materials are able to respond to external stimuli, such as magnetic fields, with significant changes in their properties. The magnetic field affects not only chemical reactions, but also the crystallographic structure and physicochemical properties of the final products. Owing to their unique properties, such materials can be used in the space industry, automotive industry, or electrical engineering.

Tests of Physicochemical and Mechanical Strength Properties of Polymer Composites on an Epoxy Resin Matrix, Modified by a Constant Magnetic Field.

The aim of the research presented in the paper was to obtain new polymer composites with strong functional properties on the Epidian 5 epoxy resin matrix. The polymer composites contained admixtures of expanded graphite, powder graphite, birch bark containing botulin, and yellow dextrin in set amounts of 20% by weight. Their various mechanical parameters and physicochemical properties were investigated. The research involved determining the effect of a constant magnetic field with magnetic induction B, under the influence of which the parameters and properties of polymer composites have been changed. For example, in a constant magnetic field with an induction of B = 0.5 T there was an increase in the hardness of the composite with an admixture of birch bark from 24.01 to 26.96 N/mm2 (12.3%), or in the composite with the addition of yellow dextrin from 26.12 to 29.93 N/mm2 (14.6%). It was also found, for example, that the water absorption of the resin itself decreased from 0.18% to 0.13%, and the composite with graphite powder from 0.48% to 0.46%. Changes in these parameters, often beneficial, may be important in terms of potential application of those new materials in industry as alternatives.

Modification of the Properties of Polymer Composites in a Constant Magnetic Field Environment.

In this paper, polymer composites based on polylactide (PLA) and epoxy resin (Epidian 5) were studied in terms of the influence of magnetic induction on their changes in physicochemical properties. The composites contained admixtures in the form of magnetite (Fe3O4) and crystalline cellulose (Avicel PH-1010) in the amount of 10%, 20%, and 30% by weight and starch in the amount of 10%. The admixtures of cellulose and starch were intended to result in the composites becoming biodegradable biopolymers to some extent. Changes in physical and chemical properties due to the impact of a constant magnetic field with a magnetic induction value B = 0.5 T were observed. The changes were observed during tests of tensile strength, bending, impact strength, water absorbency, frost resistance, chemical resistance to acids and bases, as well as through SEM microscopy and with studies of the composition of the composites that use the EDS method and of their structure with the XRD method. Based on the obtained results, it was found that the magnetic induction value changes the properties of composites. This therefore acts as one method of receiving new alternative materials, the degradation of which in the environment would take far less time.

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity.

Amino- and polyaminophthalazinones were synthesized by the palladium-catalyzed amination (alkyl- and arylamines, polyamines) of 4-bromophthalazinones in good yields. The coordinating properties of selected aminophthalazinones towards Cu(II) ions were investigated and the participation of the nitrogen atoms in the complexation of the metal ion was shown. A biological screening of the potential cytotoxicity of selected synthesized compounds on HT-29 and PC-3 cell lines, as well as on the L-929 cell line, proved that some amino derivatives of phthalazinone show interesting anticancer activities. The detailed synthesis, spectroscopic data, and biological assays are reported.

New efficient procedure for the use of diethoxyphosphoryl as a protecting group in the synthesis of polyazamacrocycles. Preparation of polyazacyclophanes derived from resorcinol.

The synthesis of polyazamacrocycles containing an electron-rich aromatic subunit derived from resorcinol is described. The reported synthetic procedure is based on the use of diethoxyphosphoryl (Dep) as an amine protecting group. The new conditions employed for the cyclization reaction allow for a generalized use of Dep in the synthesis of polyazamacrocycles.