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EN
Trimethoprim drug (TMP) complexes of copper (II), cobalt (II), and nickel (II) were prepared and discussed by using elemental analysis (C, H, N analysis), magnetic, molar conductance, FTIR, Raman spectroscopy, electron spin resonance (ESR) and UV-vis spectroscopy analyses. TMP drug coordinated as a tridentate ligand towards the respected three metal ions through two nitrogen atoms of amino groups and nitrogen atom of pyrimidine ring which flanked between –NH2 groups, these assignments confirmed by spectroscopic, magnetic, ESR and thermogravimetric analyses with formulas [Cu(TMP)(H2O)3]Cl2, [Co(TMP)(H2O)3]Cl2 and [Ni(TMP) (H2O)]Cl2. Copper (II) and cobalt (II) complexes have an octahedral geometrical structure included one TMP molecule, three coordinated water molecules and two uncoordinated chlorine atoms while, nickel(II)–TMP complex has a tetrahedral geometric configuration that involved one TMP molecule, one coordinated water molecule and two uncoordinated chlorine atoms. The activation energies and other kinetic thermodynamic parameters were estimated based on the employed of the Coats-Redfern and Horowitz-Metzger equations. The nano–structured form of the synthesized TMP complexes was confirmed dependent on the transmission electron microscopy (TEM).
2
Content available Halloysite intercalated by potassium acetate
EN
Halloysite was intercalated by the mechanochemical technique from dry components. The process efficiency of 50% was achieved. The obtained intercalate differed from the material acquired using an aqueous solution of potassium acetate. The material was analyzed employing electron microscopy, thermogravimetry, X-ray powder diffraction, and dielectric spectroscopy. It was found that the molecules and/or ions present in the interlayer spaces retain some possibility of movement. This property of the material is promising for potential application as low expensive absorbers of electromagnetic radiation.
3
Content available Polypropylene matrix composite with charcoal filler
EN
Purpose: The aim of the article is to present the thermal, electrical and mechanical properties of the produced polymer composites with a filler in the form of charcoal powder. Design/methodology/approach: The tests were carried out on samples of pure polypropylene (PP) and polymer composites, the matrix of which is polypropylene (PP), and the filler was charcoal powder with a volume fraction of 10%, 20%, 30%, 40% and 50%. The tested polymer composites in the form of granules were produced by extrusion, and then standardised test profiles were made by injection moulding. Findings: The hardness of the tested composites was determined by the Shore D method, the grain size distribution of the filler used was determined using the laser method and its thermal stability was tested using the TGA thermogravimetric analysis. The volume and surface resistivity were also determined and the density was determined. It was found that the charcoal powder used as a filler is characterised by high thermal stability - up to 600°C - and with an increase in its volume share in the polymer matrix, the hardness and density of the produced composites increases. Practical implications: The tested composites can be used as structural composites for complex elements requiring high hardness and strength. Originality/value: The research results indicate the possibility of using charcoal as a filler in polymer matrix, which, due to its low production cost, may be an alternative to expensive carbon fillers.
EN
Purpose: Cement concrete is characterized as brittle in nature, the loading capacity of which is completely lost once failure is initiated. This characteristic, which limits the application of the material, can in one way be overcome by the addition of some small amount of short randomly distributed fibers (steel, glass, synthetic). Design/methodology/approach: The present study deals with the inclusion of alkali resistant glass fibers in concrete by percentage weight of cement. The mechanical properties such as compressive strength and split tensile strength have been studied after exposing the concrete samples to elevated temperatures of up to 500°C. Water binder ratios of 0.4, 0.45, 0.5, 0.55 and 0.6 have been used to prepare design mix proportions of concrete to achieve a characteristic strength of 30 MPa. The depth of carbonation post elevated temperature exposure has been measured by subjecting the concrete samples to an accelerated carbonation (5%) condition in a controlled chamber. Findings: Conclusions have been drawn in accordance to the effect of fiber replacement and temperature increment. The concrete mixes with fiber content of 1% by weight of cement had shown better strength in compression and tension compared to the other dosages and conventional concrete (without fiber). Microcracking due to internal stream pressure reduced the mechanical strengths of concrete at elevated temperatures. Also, from TGA it was observed that the amount of calcium carbonate in samples with fiber added, post carbonation was less than the mixes without fiber in it. Research limitations/implications: The present study has been limited to alkali resistant glass fibers as the conventional glass fibers undergo corrosion due to hydration. Practical implications: The glass fiber reinforced concrete can be used in the building renovation works, water and drainage works, b ridge and tunnel lining panels etc. Originality/value: Based upon the available literature, very seldom the studies are addressing the behaviour of alkali resistant glass fiber concrete and its exposure to elevated temperatures.
EN
The paper presents the results of thermogravimetric tests of engine oil used in a small turbocharged spark-ignition engine. The main observation from the research was a significant soot contamination of engine oil, that appears even at its low mileage. This indicates that also in the case of port fuel injection spark-ignition engine, high particulate matter emissions may occur. A rapid soot contamination of the oil in this engine indicates that the oil change interval should be shortened.
PL
Odpady wielomateriałowe stanowią ok. 1,6% całkowitej masy opakowań wprowadzanych na rynek. Wielomateriałowe opakowania po produktach farmaceutycznych (tzw. blistry) stanowią znaczną ilość odpadów medycznych, które, traktowane jako niebezpieczne, kierowane są obecnie do spalarni. Pomimo że jest to znaczna grupa odpadów, w dalszym ciągu nie opracowano zrównoważonej metody przetwarzania ich z odzyskiem frakcji metalicznej, która spełniałaby założenia gospodarki obiegu zamkniętego. Przedstawiono przegląd literatury dotyczącej zagospodarowania odpadów wielomateriałowych ze szczególnym naciskiem położonym na opakowania po produktach farmaceutycznych. Przedstawiono metodologię pomiarową, wyniki przeprowadzonych analiz termograwimetrycznych oraz krzywe TG i DTG odpadu pre- oraz postkonsumenckiego.
EN
Two types of wasted plastics and Al-contg. multi-material pharmaceutical packages (pre- and post-consumer) were analyzed by thermogravimetric method carried out under Ar at up to 700°C. The total mass losses were 68.27% and 58.43% for pre- and post-consumer waste, resp. A single thermal decompn. reaction was obsd. at 330°C for preconsumer waste and two reactions were obsd. at 312°C and 328°C for post-consumer waste. Sepn. of the materials for thermal processing was not necessary.
EN
The requirements set for engine oils are nowadays very high, varied, often contradictory and significantly go beyond the classic functions of engine oils. Also for the testing of engine oils, many different and advanced research methods are currently used. This article describes tests of fresh and used oil from a diesel engine using thermogravimetric analysis. This method was also used to determine the soot content of the used oil. The tests showed that the thermograms of fresh and used oil are similar, however in the oil used in the diesel engine the soot content increases.
PL
W celu uzyskania danych na temat charakterystyki morfologicznej i właściwości fizykochemicznych danego przedmiotu wykonanego z tworzyw sztucznych (lub gumy) powszechnie wykorzystywane są takie techniki, jak: spektroskopia w podczerwieni, różnicowa kalorymetria skaningowa, analiza termograwimetryczna, analiza dynamicznych właściwości mechanicznych, chromatografia żelowa czy skaningowa mikroskopia elektronowa.
EN
The thermal decomposition of supergene potassium-jarosite and sodium-jarosite samples from the weathering profiles of sulfide deposits in the northern Tibetan Plateau, China, was investigated. Electron microprobe, scanning electron microscopy, and X-ray diffraction analyses indicated the presence of nearly pure potassium-jarosite and sodium-jarosite. Thermogravimetric analysis of the potassium-jarosite sample revealed mass losses of 11.39 wt% at 443.0 °C, 20.99 wt% at 688.3 °C, and 3.18 wt% at 779.3 °C. The thermogravimetric analysis of sodium-jarosite revealed mass losses of 11.72 wt% at 447.5 °C, 21.32 wt% at 682.6 °C, and 3.70 wt% at 716.5 °C. The results provide no evidence for water-molecule loss below 400 °C, as has been reported previously for natural potassium-jarosite and sodium-jarosite. Thermal-decomposition mechanisms have been proposed for potassium-jarosite and sodium-jarosite based on X-ray diffraction analyses of samples obtained at distinct points along the respective thermal decomposition processes. A comparison of the thermal analysis patterns of potassium-jarosite and sodium-jarosite indicates that sodium-jarosite undergoes the initiation of lattice destruction at a higher temperature.
PL
Artykuł przedstawia krótki przegląd literatury dotyczącej zastosowań analizy termograwimetrycznej (TGA) w badaniu żywności. Opisano także zasadę pomiaru, wykorzystywaną aparaturę, sposób prezentacji wyników otrzymanych w tej metodzie.
EN
The article presents a short review of the literature on thermogravimetric analysis (TGA) applications in food testing. The principle of measurement, the devices used and the presentation of the results obtained in this method are also described.
EN
Thermal behaviour of epoxy-polyester powder coatings (EP) unmodified and modified with 3% of hybrid silicone-acrylic nanoparticles (NANO) was investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Silicone-acrylic nanoparticles with hybrid core-shell structure were obtained through spray drying of aqueous polymer dispersions. DSC studies were carried out using a dynamic methodology under different heating and cooling rates. The experiments revealed influence of nanoparticles presence and different temperature regimes on the polymeric coatings phase transitions. TGA and derivative thermogravimetric analysis (DTG) investigations confirmed increase in thermal stability of the modified EP as compared to unmodified EP.
PL
Termiczne właściwości epoksydowo-poliestrowych farb proszkowych (EP) niemodyfikowanych i modyfikowanych 3%-owym dodatkiem hybrydowych nanocząstek silikonowoakrylowych (NANO) analizowano metodą różnicowej kalorymetrii skaningowej (DSC) oraz termograwimetryczną (TGA). Silikonowo-akrylowe nanocząstki o hybrydowej strukturze core-shell otrzymano w wyniku suszenia rozpyłowego polimerowych dyspersji wodnych. Badania DSC przeprowadzono według standardowej dynamicznej metodologii stosując różne prędkości ogrzewania i chłodzenia. Wyniki badań ujawniły wpływ obecności nanocząstek oraz zmian prędkości ogrzewania i chłodzenia na przejścia fazowe polimerowych powłok. Analiza TGA oraz termograwimetryczne krzywe różniczkowe (DTG) potwierdziły wzrost stabilności termicznej modyfikowanych EP w porównaniu do niemodyfikowanych EP.
EN
The high-density tetranitrate ester 1,4-dinitrato-2,3-dinitro-2,3-bis(nitratomethylene)butane (SMX) was synthesized. The methods of obtaining and isolating the intermediates were optimized. The differences between the syntheses of SMX by a four- and five-step scheme were investigated. Combustion of SMX and its catalysis was studied. The possibility of replacing NG as the main plasticizer in a double-base propellant composition was demonstrated. SMX particles were shown to have pronounced crystal faceting using scanning electron microscopy. The decomposition rate equation was determined. The amount of SMX decomposed under isothermal conditions (90 °C) was 0.8 wt.% after 60 min. Thermogravimetric analysis demonstrated that heating SMX results in two different processes – decomposition and evaporation, with SMX evaporating faster than it decomposes.
13
EN
The article presents the results of studies on the rate of zinc evaporation in the atmosphere of helium and carbon monoxide (II) carried out with the thermogravimetric method. The estimated values of zinc streams were compared with the values determined based on theoretical relationships.
PL
Polizasady Schiffa zsyntetyzowano metodą polimeryzacji utleniającej 2-hydroksybenzaldehydu (2-HBA) w środowisku alkalicznym, w obecności NaOCl jako utleniacza, a następnie szczepiono otrzymany polialdehyd za pomocą amin zawierających grupy pirydynowe i pirymidynowe. Uzyskane polimery charakteryzowano metodami GPC i SEM, a ich struktury potwierdzono za pomocą spektroskopii FT-IR, 1H NMR, 13C NMR i UV-Vis. Właściwości optyczne polizasad Schiffa analizowano spektroskopią fluorescencyjną i UV-Vis, a właściwości termiczne określono metodami TG, DTA i DSC. Korzystając z woltamperometrii cyklicznej (CV) oraz pomiarów przewodności ciała stałego metodą czteropunktową badano właściwości elektrochemiczne otrzymanych polimerów. Pomiary te wskazują na półprzewodnikowy charakter polimerów. Stwierdzono, że wartości liczbowo średniego ciężaru cząsteczkowego (Mn), wagowo średniego ciężaru cząsteczkowego (Mw) i stopnia polidyspersji (Đ) ­poli(2-hydroksybenzaldehydu) (P-2HBA) wyznaczone na podstawie analizy GPC są równe, odpowiednio, 5900, 5450 oraz 1,08. Szerokość elektrochemicznej przerwy energetycznej (E'g) oznaczono metodą CV, natomiast szerokość optycznej przerwy energetycznej (E'g) za pomocą spektroskopii UV-Vis.
EN
Schiff bases polymers were synthesized from 2-hydroxybenzaldehyde (2-HBA) via oxidative polymerization method in an aqueous alkaline medium in the presence of NaOCl as an oxidant. Then, these polymeric Schiff bases were prepared from the polyaldehyde by grafting each of them with different amines containing pyridine and pyrimidine groups. The structures of polymers were confirmed by FT-IR, 1H NMR, 13C NMR, and UV-Vis measurements. The polymers were characterized by GPC and SEM analyses. Furthermore, their optical properties were determined by UV-Vis and fluorescence spectroscopy, their electrochemical properties by cyclic voltammetry (CV) analysis and solid state conductivity measurements by the four-point probe technique, their thermal behavior by TG, DTA, and DSC measurements. The electrical conductivity of the polymers was also measured and found that they are semiconductive. The number average molecular weight (M'n), the weight average molecular weight (M'w), and dispersity (Đ) values of the polymers were found from GPC analysis and were equal 5900, 5450 and 1.08, respectively, for poly(2-hydroxybenzaldehyde) (P-2HBA) polymer. Electrochemical energy gap (E'g) was found by CV, whereas optical band gap (E'g) was determined by UV-Vis measurements.
EN
In this study, flame retardant modification of partially oriented (POY, partially oriented yarn) poly(ethylene terephthalate) (PETPOY) fibers were applied using a high temperature bath method similar to dyeing fibers with disperse dyes. The flame retardant modifier used in this work – water-glass (WG) – was commercially available technical product. The flammability of fibers was evaluated by limiting oxygen index (LOI) method. Samples of the modified fibers were examined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Effect of the flame retardant on change in the supermolecular structure of PETPOY fibers was evaluated using wide- and small-angle X-ray diffraction (WAXS and SAXS). As a result of the applied modification, PETPOY fibers were provided with effective and durable flame retardant properties. Also noteworthy is the relatively low cost and simplicity of applying the proposed technology.
PL
Do modyfikacji trudnozapalnej częściowo zorientowanych włókien z poli(tereftalanu etylenu) (PETPOY) zastosowano, podobnie jak w wypadku procesu barwienia włókien PET barwnikami zawiesinowymi, wysokotemperaturową metodę kąpielową. W charakterze modyfikatora użyto technicznego produktu handlowego – szkła wodnego (WG). Palność włókien oceniano metodą wskaźnika tlenowego (LOI). Próbki zmodyfikowanych włókien badano za pomocą różnicowej kalorymetrii skaningowej (DSC) i analizy termograwimetrycznej (TGA). Wpływ dodatku WG na zmianę struktury nadcząsteczkowej włókien PETPOY oceniano na podstawie wyników szeroko- i małokątowej dyfraktometrii rentgenowskiej (WAXS i SAXS). Otrzymane modyfikowane włókna PETPOY wykazywały trwale zmniejszoną palność. Dodatkową zaletą zastosowanej metody modyfikacji jest jej stosunkowo niski koszt oraz prostota aplikacji.
18
Content available remote Radiograficzne i termograwimetryczne badania pirolizy pojedynczej cząstki drewna
PL
Opisano proces pirolizy pojedynczej cząstki drewna. Za pomocą termograwimetrii, badań w piecu wysokotemperaturowym oraz metod radiograficznych przeprowadzono analizę procesu pirolizy. Analizowano szybkość dekompozycji termicznej i jej stopień w funkcji czasu. Badano poddane pojedyncze próbki w formie sosnowych sześcianów o boku 18 mm. Analiza termograwimetryczna mająca na celu wyznaczenie przedziałów, w jakich zachodzi proces, poprzedziła badania wykonane w piecu wysokotemperaturowym. Próbki po eksperymentach zostały poddane badaniom radiograficznym celem zobrazowania zmian gęstości drewna w funkcji czasu. Na zdjęciach zaobserwowano, iż piroliza zachodzi od naroży próbki, a następnie pozostaje tylko niespirolizowany rdzeń w środku próbki. Badania potwierdziły duże możliwości radiografii w ocenie pirolizy.
EN
Pyrolysis process of a single wood particie is described in the paper. Thermogravimetric and radiography techniques and pyrolysis in a high-temperature kiln were applied in the experiments. The thermal decomposition rate as a function of time was analyzed. Pine cubes with a side of 18 mm were used as samples. High-temperature kiln tests were preceded by thermogravimetric analysis aiming to determine temperature ranges in which the process took place. The samples after tests were analyzed using radiographic methods to visualize the changes in wood density as a function of time. It was observed on the photographs that pyrolysis started from sample corners, while only a core in the center of samples remained unchanged. Radiography experiments have a big potential in pyrolysis research.
EN
The mechanism and kinetics of oxidation of Inconel 617 and 625 alloys in air atmosphere were investigated. Materials were examined by the thermogravimetric method. The X-ray diffraction spectrometer (XRD) was used to observation change in chemical composition the oxide scales of Inconel alloys specimens. Oxidation kinetics was determined from weight-change measurements. The surface and microstructure of the sample were observed in an optical microscope (OM) and a scanning electron microscope (SEM). The results showed that the oxide scales of the alloys were compact and continuous. The layer were contained as the outer of Cr2O3, and the internal of NiCr2O4 spinel, NiO and other oxides. Oxides’ scales with good adherence were formed on the surface of alloys. The kinetics and thermodynamic parameters of oxides formation were calculated and discussed for both alloys.
EN
Composites of polyethylene matrices and fillers consisting of finely ground pistachio shells and sunflower husks were manufactured. These materials were subjected to a series of tests for the purpose of examining their processing qualities, physical, mechanical and thermal characteristics, flammability and resistance to environmental factors, determining their feasibility and application paths. The relationship between the natural fiber composites' morphology and stability was described. Based on the obtained test results, the influence of the lignin content and secondary components in the fillers' structure on the thermal stability of the composites was confirmed. It was also proven that the porosity of the composites and the hemicellulose content in the filler influenced the composites' capacity to take up considerable amounts of water.
PL
W ramach pracy wytworzono kompozyty na osnowie polietylenu napełnione drobno mielonymi łupinami pistacji oraz łuskami słonecznika. Materiały te poddano serii badań mających na celu poznanie ich właściwości przetwórczych, fizycznych, mechanicznych i termicznych, palności oraz odporności na działanie czynników środowiskowych, warunkujących możliwości i kierunki ich zastosowania. Określono związek między morfologią a stabilnością badanych kompozytów polimerowych z napełniaczami roślinnymi (NFC, z ang. natural fibre composites). Zbadano wpływ zawartości ligniny i pozostałych składników napełniaczy na stabilność termiczną NFC. Dowiedziono również, że na zdolność NFC do pochłaniania znacznych ilości wody zasadniczy wpływ ma porowatość kompozytów oraz zawartość hemicelulozy w napełniaczu.
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