Tag Archives: Special purpose materials

Products of entertainment pyrotechnics as specific market products

Products of entertainment pyrotechnics as specific market products.

Please cite as: CHEMIK 2012, 66, 1, 64-68 The paper outlines selected statements of the EU Directive of pyrotechnic articles that are to be placed on the EU market. It discloses design principles of entertainment pyrotechnical products (fireworks) and formulas of flash powder mixtures used for such products. The particular attention is paid to how the design features and manufacturing accuracy of so called rumble firecrackers influence the expected application effects. Keywords: entertainment pyrotechnical products (fireworks), European Pyrotechnical Directive, safety Read more: pdf-icon...
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Methods for obtaining octogen (hmx)

Methods for obtaining octogen (hmx).

MATYS Z., POWAŁA D., ORZECHOWSKI A., MARANDA A. Please cite as: CHEMIK 2012, 66, 1, 58-63 The paper describes the methods for manufacturing octogen, a modern, thermally stable, brisant explosive. Two production technologies for obtaining the compound developed at the Institute of Industrial Organic Chemistry have been presented. The first method uses the nitration of urea with a nitrating mixture (nitric acid and oleum), and the cyclisation of dinitrourea (DNU) with hexamethylenetetramine (HMTA) and ammonia to form a semiproduct ? DPT, which is then subject to nitrolysis after adding the solution of ammonia nitrate in nitric acid. This method has been implemented in industrial applications. The second method consists in the nitrolysis of hexamethylenetetramine (HMTA) with the solution of ammonium nitrate in nitric acid in the presence of acetic acid, acetic anhydride and trioxane (a trimer of formaldehyde). Keywords: explosives, octogen, synthesis, technology Read more: pdf-icon...
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Study of the detonation parameters the mixtures of nitroguanidine with flaked aluminium

Study of the detonation parameters the mixtures of nitroguanidine with flaked aluminium.

MARANDA A., SZAŁKOWSKI K., PASZULA J., ORZECHOWSKI A., POWAŁA D., Please cite as: CHEMIK 2012, 66, 1, 50-57 At this point in time nitroguanidine is used as component of explosive mixtures described with high detonation parameters and low sensibility to mechanical stimuli. It is also used in some kinds of rocket propellant. The results of attempts to achieve nitroguanidine with isometric grains are shown in this paper. Then it was used for preparation of mixture with aluminium powder with different content of metallic component. Then it was used for preparation of mixtures with flaky aluminium powder with different content of metallic component. The measurements of detonation velocity and intensively of blast wave was taken for received mixtures. Keywords: nitroguanidine, explosives, detonation parameters Read more: pdf-icon...
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How to prepare an explosion protection document

How to prepare an explosion protection document.

Piotrowski T., Domański W. Please cite as: CHEMIK 2012, 66, 1, 31-40 This paper presents a method of preparing an explosion protection document (EPD). This document is required by directive ATEX 137 and the decree of the Minister of Economy implementing this directive into Polish law. A three-part structure of the EPD is proposed: part 1 ?General information?, which includes statements and deadlines relating to the EPD; part 2 ?Detailed information?, which includes an assessment of the hazard and risk of explosion and ways of preventing and protecting against the effect of an explosion; part 3 ?Information and supplementary documents?, which includes lists of reports, certificates, confirmations, procedures, etc. A correct assessment of the risk of explosion is the basis of a well-prepared EPD. This paper presents a diagram of a sequence of events that can lead to an explosion. An algorithm for emergency scenarios that result in an explosion at the workplace was worked out on the basis of this diagram. The algorithm was supplemented with...
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Morphology and Thermal Properties of Expanded Graphite (EG)/Poly(ethylene terephthalate) (PET) Nanocomposites

Morphology and Thermal Properties of Expanded Graphite (EG)/Poly(ethylene terephthalate) (PET) Nanocomposites.

PASZKIEWICZ S., ROSŁANIEC Z., SZYMCZYK A., SPITALSKY Z., MOSNACEK J. Please cite as: CHEMIK 2012, 66, 1, 21-30 Nanocomposites based on poly(ethylene terephtalate) and expanded graphite (PET/EG) with 0.025-0.4wt.% nanofiller content were prepared by in situ condensation polymerization (polycondensation). Their morphology was determined (TEM, SEM), thermal stability by TGA (temperatures corresponding to: 2% (T-2%),10% (T-10%) and 50% (T-50%) weight loss, activation energy by Freeman-Carroll method (Ea), temperature of maximum mass loss rate of nanocomposites in air and in argon. Also the influence of graphene was assessed on the physical transition occurring in the PET (DSC). The results of PET/EG nanocomposites were compared with the unmodified PET. SEM images of nanocomposite exhibit a diphasic structure of PET / EG of clearly visible graphene platelets, and few agglomerates. The study of nanocomposites of PET / EG using TEM techniques confirmed the presence of grephene platelets size of about 1÷10 ?m. This means, that in situ polymerization has been used to obtain exfoliated and relatively evenly spaced graphene plates...
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A new tool for synthesis of organic optoelectronic materials

A new tool for synthesis of organic optoelectronic materials.

Piotr BAŁCZEWSKI - Department of Heteroorganic Chemistry - Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Łódź; Institute of Chemistry, Environmental Protection and Biotechnology, Jan Dlugosz University, Czestochowa; Agnieszka BODZIOCH, Joanna SKALIK - Department of Heteroorganic Chemistry - Centre of Molecular and Macromolecular Studies,Polish Academy of Sciences, Łódź Please cite as: CHEMIK 2012, 66, 1, 11-20 Abstract: Organic materials, featuring spatially developed systems of ?-conjugated bonds, are currently intensively investigated as materials for applications in organic electronics and optoelectronics. Benefits coming from the use of organic semiconductors in construction of optoelectronic elements, such as OLEDs, OFETs, OLETs or OPVs are mainly connected with reduction of manufacturing costs of thin films made from easily solution-processable, organic compounds, convenient chemical modulation their optoelectronics properties, as well as compatibility of organic materials to flexible substrates. Despite the significant progress which has been made in recent years in this field, many problems associated with the processing and efficiency of organic semiconducting materials are still unresolved. This paper will present results...
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One more function for microbial fuel cells in treating wastewater: producing high-quality water

One more function for microbial fuel cells in treating wastewater: producing high-quality water.

ZHEN HE ? Department of Civil Engineering and Mechanics, University of Wisconsin-Milwaukee, USA Please cite as: CHEMIK 2012, 66, 01, 3-10 Abstract: A sustainable wastewater treatment technology should effectively reduce contaminant concentration, recovery energy contents and minimize liquid discharge. A potential candidate for such a technology is a microbial fuel cell (MFC) that can produce bioelectricity directly from wastewater treatment. However, the treated effluent from MFCs is not reused because of unsatisfied water quality. To produce high-quality water using MFCs, we proposed and studied two approaches with integrated membrane technologies. Especially, the osmotic MFCs that take advantage of both forward osmosis and MFCs have been proven feasible with bench-scale studies. The new function of producing high-quality water, although still very challengeable, will make MFCs a promising approach for sustainable wastewater treatment. Keywords: Microbial Fuel Cells, Bioenergy, Forward Osmosis, Membrane, Wastewater Treatment Read more: pdf-icon...
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Exergy and explosives BIEGAŃSKA J.

Jolanta BIEGAŃSKA ? Department of Technologies and Installations for Waste Management, Silesian University of Technology, Gliwice Abstract: Exergy is a term introduced to thermodynamics to determine ability to perform work in the environment with relation to human activity. Manufactured industrial explosive  materials are destined mainly to get unmined stone. Hence, their use is connected with the realization of the effective work. The exergy loss related to obtaining solid stone  in mining where explosive materials are used should be taken into consideration. Please cite as: CHEMIK 2013, 67, 13, 47-52 Introduction In thermodynamics, an ability to perform work under natural conditions, within the area of human production is a touchstone for determining quality of energy. This criterion of quality was called exergy by Z. Rant [1]. The notion of exergy is related to the irreversibleness of thermodynamic processes. A numerous bibliography of over 2500 items concerning suggestions how to use exergy was collected by Sciubba and Wall [2]. In Poland, professor Szargut [3÷11] dedicated a lot...
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Assessing the parameters of blast waves in the air generated by the detonation of 4,4?,5,5?-tetranitro-2,2?- biimidazole dihydrate and 3,3?-diaminoazoxyfurazan (DAAF) SZALA M., LEWCZUK R., PASZULA J.

Mateusz SZALA, Rafał LEWCZUK, Józef PASZULA ? Division of New Technology and Chemistry, Military University of Technology, Warsaw Abstract: The paper presents the results of studies covering the assessment of blast waves generated in the air by the detonation of 4,4?,5,5?-tetranitro-2,2?-biimidazole dihydrate  (TNBI?2H2O) and 3,3?-diamino-4,4?-azoxyfurazan (DAAF). Both compounds used in the studies have been produced at the Department of Explosives of the Military  University of Technology. As the reference material 2,4,6-trinitrotoluene (TNT) and 1,3,5,7-tetranitro-1,3,5,7-tetraaza-cyklooctane (octogen) were used. It has been  experimentally proven that TNBI?2H2O generates burst waves with parameters similar to the waves generated by octogen (HMX). Please cite as: CHEMIK 2013, 67, 13, 41-46 Introduction Until recently ?explosives? were associated solely with broadly defined military applications. Because of the more and more common use of chemical compounds and mixtures capable of causing an explosive conversion in such lines as: coal mining and petroleum, automotive industry, metallurgy or construction, the knowledge of the applications of high energy compounds becomes more and more widespread. Recently, the...
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New shaped charges of flexible characteristics as an example of using silicone polymers in the technology of explosives

Karolina NIKOLCZUK, Justyna HADZIK, Zenon WILK ? Institute of Industrial Organic Chemistry in Warsaw, Branch in Krupski Młyn Abstract: The objective of this paper was to describe a series of tests related to the application of silicone polymers which can be added and modified with explosive materials  under ambient conditions without using the complex technological processes, high temperatures or complex, multi-stage chemical reactions. Moreover, the selection of  silicone polymers was economically justified and conducted regarding their availability in Poland. The technology for obtaining flexible linear shaped charges (LSC) was  developed and field tests of obtained charges were carried out, that is, the detonation velocity and effectiveness were tested on the basis of punching a steel plate of a specified thickness. Please cite as: CHEMIK 2013, 67, 13, 33-40 Introduction For more than 50 years, polymers and their derivatives have been used as components of propelling charges in artillery and small arms ammunition, and in explosives of reduced sensitivity to mechanical stimuli, and they have been...
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