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1

Thermal analysis of polymeric ionic liquids (using TGA and DSC techniques)

Adamczyk Magda, Masłowska-Lipowicz Iwona, Wyrębska Łucja

Technologia i Jakość Wyrobów

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2022

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R. 67

155--169

EN

The article presents an analysis of the structure stability of polymeric ionic liquids. Using DSC (Differential Scanning Calorimetry) and TGA (Thermogravimetric analysis) techniques, new polymeric ionic liquids containing polyhexamethylene biguanide (PHMB) groups as cations and aryl carboxylate groups as anions derived from benzoic and salicylic acids were studied. The DSC technique measures the heat absorbed or released by the sample during a programmed increase or decrease in temperature. On the other hand, using thermogravimetric measurement (TGA), the so-called thermogravimetric curve, which describes the dependence of the sample mass on temperature. The results obtained during the tests allowed to determine the enthalpy and glass transition temperatures for both samples.

PL

W artykule przedstawiono analizę stabilności struktury polimerycznych cieczy jonowych. Za pomocą technik DSC (Differential Scanning Calorimetry) oraz TGA (Thermogravimetric analysis) zbadano nowe polimeryczne ciecze jonowe zawierające grupy poliheksametylenobiguanidyny (PHMB), jako kationy oraz grupy arylokarboksylanowe, jako aniony pochodzące od kwasu benzoesowego i salicylowego. Technika DSC polega na pomiarze ciepła pochłanianego bądź wydzialnego przez próbkę podczas zaprogramowanego wzrostu lub zmniejszenia temperatury. Natomiast za pomocą pomiaru termograwimetrycznego (TGA) otrzymuje się tzw. krzywą termograwimetryczną, która opisuje zależność masy próbki od temperatury. Rezultaty uzyskane podczas badań pozwoliły na wyznaczenie entalpii oraz temperatur zeszklenia dla obu próbek.

2

Mechanical characterization of Abutilon Indicum fiber nonwoven fabric epoxy composite materials

Chinnan Murugan Mohanraj, Ramasamy Rameshkumar, Mariappan Mathanbabu, Rajendran Barathiraja

Polimery

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2022

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Vol. 67, nr 11-12

595--601

EN

The effect of nonwoven Abutilon Indicum fiber content (20, 25, 30, 35, and 40 wt%) on the structure (FTIR, SEM) and selected mechanical and thermal (TGA) properties of epoxy resin was investigated. The best mechanical properties were obtained with a fiber content of 35 wt%. The tensile strength of the composite was about 40 MPa, the flexural strength over 60 MPa, and the compressive strength about 48 MPa. Moreover, the composite showed the fracture energy about 0.44 J.

PL

Zbadano wpływ zawartości włókna Abutilon Indicum (20, 25, 30, 35 i 40% mas.) na strukturę (FTIR, SEM) oraz wybrane właściwości mechaniczne i termiczne (TGA) żywicy epoksydowej. Najlepsze właściwości mechaniczne uzyskano przy zawartości włókna 35% mas. Wytrzymałość na rozciąganie tego kompozytu wynosiła ok. 40 MPa, wytrzymałość na zginanie powyżej 60 MPa, a na ściskanie ok. 48 MPa. Natomiast energia pęknięcia wynosiła ok. 0,44 J.

3

The effect of kenaf loading on kenaf/ABS composites structure and thermal properties

Mashelmie S., Rabiatul Manisah M., Bahiyah Baba N., Mohd A.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 111, nr 2

49--56

EN

Purpose: Many manufacturers have recently become interested in using fiber-reinforced polymer composites (FRPs) in structural applications. Synthetic fibres, such as carbon and glass fibres, have been commercialised internationally for decades, but they cause environmental issues because synthetic fibres are non-biodegradable and difficult to recycle once they have served their purpose, potentially polluting the environment. Thus, natural fibre composites like kenaf is a possible replacement for synthetic fibre due to their superior physical and mechanical properties. Kenaf appears to be the best candidate for replacing synthetic fibres in order to accomplish the goal of environmental preservation while also displaying excellent properties such as equivalent specific strength, low density, and renewable resources. Design/methodology/approach: The kenaf fiber was treated in KOH and added to ABS matrix to produce new composites at different loading (10, 15, 20 and 25 wt.%) by using Two Roll Mill machine. The influence of the fiber on the composites properties was evaluated. The produced material was subjected to SEM, MFI, TGA and DSC analysis. Findings: The incorporation of the treated kenaf fiber has an influence on the properties of kenaf/ABS composites. The addition of 10 wt.% kenaf was found to be the best loading with MFI value, initial degradation temperature and glass transition temperature at 0.8208 g/10 min, 322.63°C and 130°C respectively. The fiber was well dispersed in the matrix and shown good adhesion to the ABS. The addition of treated fiber contribute to a reduction in the MFI, improved the thermal stability of the composites and typical effects of Tg of the composite compare to pure ABS. Research limitations/implications: The results suggest the need to continue the study in order to further analyse higher kenaf loading and shed more light on the properties of the composites to improve understanding of kenaf/ABS composites. Originality/value: Obtained results are a solution to alternative of synthetic fibers, which may contribute to the sustainable development of composites materials industry through the utilization of kenaf fiber with ABS matrix.

4

In situ methanolic solvent synthesis, spectroscopic and thermogravimetric characterizations of three new transition metal complexes of trimethoprim drug

Refat Moamen S., Al-Humaidi Jehan Y., El-Sayed Mohamed Y., Hassan Reham F.

Polish Journal of Chemical Technology

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2021

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Vol. 23, nr 1

60--67

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).

5

Wyznaczanie składu nieznanej mieszaniny trójskładnikowej metodą TGA

Dennenwaldt Teresa

LAB Laboratoria, Aparatura, Badania

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2021

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R. 26, nr 2

35--37

PL

Oznaczanie ilościowe składu związku metodą analizy termograwimetrycznej (TGA) jest trudne, gdy poszczególne etapy rozkładu nakładają się na siebie. Jeżeli rozkład pojedynczych składników nie wpływa na proces rozkładu pozostałych składników, skład mieszaniny można obliczyć na podstawie zachowania poszczególnych składników podczas rozkładu. W tym artykule zaprezentowano sposób przeprowadzenia takiej analizy na przykładowej próbce mieszaniny trójskładnikowej siarczanu baru, sadzy i lignosulfonianu.

6

Identyfikacja polimerów termoplastycznych: analiza rozkładu metodą TGA

Dandekar Santosh

LAB Laboratoria, Aparatura, Badania

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2021

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R. 26, nr 2

31--34

PL

Pomiary metodą TGA wykonano na 22 różnych polimerach z użyciem dwóch różnych programów temperaturowych. Oznaczono zawartość składników lotnych (w większości przypadków: wody), ubytek masy i temperaturę reakcji pirolizy, zawartość sadzy wytworzonej w procesie pirolizy oraz zawartość popiołu. W artykule przedstawiamy różnice tych wielkości dla poszczególnych polimerów poddanych analizie. Omawiamy również sposób, w jaki wielkości wyznaczone na podstawie pomiarów TGA można wykorzystać do identyfikacji składu materiałów polimerowych.

7

Analysis of Optimum Temperature and Calcination Time in the Production of CaO Using Seashells Waste as CaCO3 Source

Dampang Sarah, Purwanti Endah, Destyorini Fredina, Kurniawan Setyo Budi, Abdullah Siti Rozaimah Sheikh, Imron Muhammad Fauzul

Journal of Ecological Engineering

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2021

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Vol. 22, nr 5

221--228

EN

Seashells waste is abundant in coastal area, especially in the locations where fisheries are a major occupation. This abundant resource of seashells opens a new opportunity further utilization. Seashells waste is a source of CaCO3, which may be converted into CaO via the calcination process. This study analyzed the characteristics of the CaO produced via calcination process at different temperature and calcination time. The calcination process was carried out at a temperature of 800°C, 900°C, and 1000°C with variation of 2, 3, and 4 hours in time. The Fourier transform infrared spectroscopy (FTIR) result showed that the spectrum of 2513 cm-1 as an indication of the C-H group containing CaO appearing after calcination. The FTIR results suggest that the calcination time did not gave major alteration to the functional groups. The results of X-ray diffraction (XRD) analysis showed that CaO laid at the angle of 58.1° and 64.6°. Scanning Electron Microscopy–Energy Dispersive X-Ray Spectroscopy (SEM-EDS) results showed that the most significant compositional outcome after the calcination process was Ca and O at all temperatures and calcination times. All calcined seashells showed rough surface and irregular shape particles. The result of a Thermogravimetric analysis (TGA) suggested that the highest mass alteration occurred at a temperature of 800°C with 78 mins of calcination time.

8

Thermal gravimetric analysis of glass fiber reinforced composite for understanding the impact of copper oxide in relation to titanium oxide filler particles

Alam Shahinoor, Chowdhury Mohammad Asaduzzaman

Composites Theory and Practice

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2021

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R. 21, nr 1-2

12--21

EN

In this work, the composite samples required to investigate their thermal properties were fabricated employing the conventional hand lay-up technique, followed by a light compression molding process. A fixed weight of plain woven glass fiber and epoxy with four different types of fillers as calcium carbonate (CaCO3), aluminum oxide (Al2O3), magnesium oxide (MgO) and titanium oxide (TiO2) or copper oxide (CuO) of different weights (5, 10 and 15 g) were studied. According to thermal gravimetric analysis (TGA), it was observed that the melting point (Tm) and glass-transition temperature (Tg) are affected by the presence of CuO and TiO2, which indicate the degree of composite crystallinity established by the stronger interfacial interaction by the CuO than that of the TiO2 particles and the amorphous region of the chain. These studies were supported by examination of the surface morphology of the composites by means of scanning electron microscopy (SEM).

9

Charakterystyka termograwimetryczna procesu zgazowania wybranych rodzajów biomasy

Grzywacz Przemysław, Czerski Grzegorz, Gazda-Grzywacz Magdalena

Przemysł Chemiczny

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2020

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T. 99, nr 3

386--390

PL

Przedstawiono wyniki badań termograwimetrycznych procesu zgazowania w atmosferze CO₂ trocin, łupin orzecha włoskiego, siana oraz kolb oczyszczonych z ziaren kukurydzy. Oznaczono reaktywność surowców, wskazano etapy zgazowania, a także obliczono parametry kinetyczne procesu. Największą energię aktywacji i szybkość reakcji zaobserwowano w przypadku karbonizatu siana (237,2 kJ/mol).

EN

Sawdust, walnut shells, cobs purified from corn grains and hay were gasified under CO₂ by thermogravimetry to det. process stages reactivity of raw materials and kinetic parameters of the gasification stage. The highest activation energy was obsd. by the gasification of hay carbonizate (237.2 kJ/mol) and surprisingly the reaction showed also the highest rate.

10

PET/Cloisite®15A composite fibers – studies on the structure and the flame inhibition mechanism

Fabia Janusz, Gawłowski Andrzej, Rom Monika, Ślusarczyk Czesław, Biniaś Włodzimierz, Brzozowska-Stanuch Anna, Puchalski Michał

Polimery

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2020

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T. 65, nr 9

622--631

EN

The improvement of poly(ethylene terephthalate) (PET) fibers flame retardancy is usually achieved by using antipyrenes, which may be incorporated into polyester molecules during polycondensation or are physically mixed with polymer in the fiber formation process. In this article we present an alternative method to reduce the flammability of PET fibers and fabrics which is analogous to dyeing them with a dispersed dyes in a high temperature bath. We have tested this method many times using various modifiers so far. This time, we applied a commercial organophilized montmorillonite Cloisite®15A (C15A). In the presented work, using Limited Oxygen Index (LOI) flammability tests and the thermogravimetric analysis (TGA) method, the effectiveness of the modification used was demonstrated and its optimal variant was determined. Based on Fourier Transform-Infrared Spectroscopy (FT-IR) studies, the existence of interactions between PET macromolecules and the C15A modifier in the entire temperature range of the oxidative degradation was confirmed. Using the Wide-Angle X-ray Scattering (WAXS) and Small-Angle X-ray Scattering (SAXS) methods, the basic parameters of the nanostructure of the studied fibers were determined, and their nanocomposite nature was confirmed. The most important goal, which was successfully achieved, was to explain the mechanism of flame inhibition by the applied modifier C15A.

PL

Poprawę właściwości palnych włókien poli(tereftalanu etylenu) (PET) można uzyskać w wyniku zastosowania uniepalniaczy, które mogą być wprowadzane do mieszaniny reakcyjnej podczas polikondensacji poliestru lub fizycznie mieszane z polimerem w procesie tworzenia włókien. W niniejszym artykule przedstawiono alternatywną metodę zmniejszania palności włókien i wyrobów tekstylnych z PET, analogiczną do procesu ich barwienia rozproszonymi barwnikami w kąpieli wysokotemperaturowej. Metodę tę testowaliśmy już wielokrotnie przy użyciu różnych modyfikatorów. Tym razem zastosowaliśmy handlowo dostępny organofilizowany montmorylonit Cloisite®15A (C15A). Za pomocą testów palności (określano wartość LOI – wskaźnika tlenowego) oraz analizy termograwimetrycznej (TGA) wykazano skuteczność zastosowanej modyfikacji i określono jej optymalny wariant. Na podstawie badań spektroskopowych FT-IR (spektroskopia w podczerwieni z transformacją Fouriera) potwierdzono występowanie oddziaływań między makrocząsteczkami PET i modyfikatora C15A w całym zakresie temperatury, obejmującym proces degradacji oksydacyjnej. Metodami szeroko i mało kątowej dyfrakcji rentgenowskiej (WAXS i SAXS) określono podstawowe parametry nanostruktury badanych włókien oraz potwierdzono ich nanokompozytowy charakter. Wyjaśniono także mechanizm inhibitowania płomienia przez zastosowany modyfikator C15A.

11

Dynamic mechanical analysis and thermal analysis of untreated Coccinia indica fiber composites

Balu S., Sampath P. S., Bhuvaneshwaran M., Chandrasekar G., Karthik A., Sagadevan Suresh

Polimery

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2020

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T. 65, nr 5

357--362

EN

A natural fiber reinforced polymer matrix composites (FRCs) was prepared by the compression molding method. The natural fiber named Coccinia indica (CI) was employed to fabricate FRCs. The impact of fiber length on storage modulus, loss modulus and loss of weight in the FRCs were determined using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). The results revealed that a fiber length of 40 mm shows better storage modulus and nominal loss modulus owing to the higher interfacial bonding between fiber and matrix. In other investigated fiber lengths, the storage modulus is poor and loss modulus is high, which is due to inefficient stress transfer.

PL

Metodą wytłaczania przygotowano próbki kompozytów (FRC) na osnowie polimerowej wzmocnionej włóknami naturalnymi Coccinia indica (CI). Wpływ długości zastosowanych włókien na moduł zachowawczy, moduł stratności i ubytek masy badanych FRC oceniano za pomocą dynamicznej analizy mechanicznej (DMA) i analizy termograwimetrycznej (TGA). Stwierdzono, że kompozyty z udziałem włókien o długości 40 mm wykazują korzystniejszy moduł zachowawczy i nominalny moduł stratności, dzięki lepszemu wiązaniu międzyfazowemu włókna z osnową. W wypadku kompozytów z zawartością włókien o innych długościach moduł zachowawczy jest mały, a moduł stratności duży, co wynika z nieefektywnego przenoszenia naprężeń.

12

Preparation of yttrium citrate by the reaction of yttrium hydroxide with sodium citrate

Janusz Władysław, Skwarek Ewa, Sternik Dariusz

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

51--59

EN

A method of obtaining yttrium citrate by transformation of freshly precipitated yttrium hydroxide in the solutions of sodium citrate under hydrothermal conditions has been proposed. To determine the synthesis time, transformation kinetics consisted in by taking the solid samples for the C and H contents analysis after 6, 12, 24, 48 and 72 hours of synthesis. Simultaneously these samples were subjected to the thermogravimetric analysis. As follows from the thermogravimetric analysis adsorption of citrate dihydrate on yttrium hydroxide is observed in the initial period up to 24 hours. Later the yttrium citrate dihydrate is formed. The thermogravimetric analysis of the final product i.e. amorphous yttrium citrate showed that the decomposition/oxidation of the sample occurs in six stages the particle size analysis method of static light scattering showed that 45% of the particles had a diameter of 0.1-0.9 µm and 55% of particles with sizes from 0.9 to 5 µm.

13

Halloysite intercalated by potassium acetate

Mariusz Adamczyk, Katarzyna Małycha, Karol Kułacz, Michał Pocheć, Kazimierz Orzechowski

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

235--243

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.

14

Synthesis and characterization of Li2MnO3 nanoparticles using sol-gel technique for lithium ion battery

Chennakrishnan Sandhiya, Thangamuthu Venkatachalam, Subramaniyam Akshaya, Venkatachalam Viknesh, Venugopal Manikandan, Marudhan Raju

Materials Science Poland

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2020

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Vol. 38, No. 2

312--319

EN

Nanoparticles of Li2MnO3 were fabricated by sol-gel method using precursors of lithium acetate and manganese acetate, and citric acid as chelating agent in the stoichiometric ratio. TGA/DTA measurements of the sample in the regions of 30 °C to 176 °C, 176 °C to 422 °C and 422 °C to 462 °C were taken to identify the decomposition temperature and weight loss. The XRD analysis of the sample indicates that the synthesized material is monoclinic crystalline in nature and the calculated lattice parameters are 4.928 Å (a), 8.533 Å (b), and 9.604 Å (c). The surface morphology, particle size and elemental analysis of the samples were observed using SEM and EDAX techniques and the results confirmed the agglomeration of nanoparticles and, as expected, Li2MnO3 composition. Half cells of Li2MnO3 were assembled and tested at C/10 rate and the maximum capacity of 27 mAh/g was obtained. Charging and discharging processes that occurred at 3 V and 4 V were clearly observed from the cyclic voltammetric experiments. Stability of the electrodes was confirmed by the perfect reversibility of the anodic and cathodic peak positions observed in the cyclic voltammogram of the sample. The Li2MnO3 nanoparticles exhibit excellent properties and they are suitable for cathode materials in lithium ion batteries.

15

Termiczna konwersja odpadów rolniczych w celu poprawy ich parametrów energetycznych

Dębowska Aleksandra, Kopia Agnieszka, Magdziarz Aneta

Hutnik, Wiadomości Hutnicze

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2020

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Vol. 87, nr 4

82--86

PL

Celem prezentowanych badań była charakterystyka termicznej przemiany rolniczych odpadów biomasowych, tj. wytłoków winogron i gałązek kiwi oraz charakterystyka karbonizatów uzyskanych w beztlenowym procesie w temperaturze 1000°C i 1200°C. Budowę morfologiczną i zachowanie termiczne analizowanych materiałów wykonano odpowiednio metodami SEM-EDAX i TGA. Na podstawie danych termograwimetrycznych określono charakterystykę termicznej przemiany surowej biomasy i karbonizatu. Następnie w oparciu o wyniki TGA wyznaczono parametry kinetyczne tj. energię aktywacji Ea i współczynnik przedwykładniczy A. Wartości energii aktywacji uzyskane dla gałęzi kiwi są wyższe niż wartości obliczone dla biomasy pochodzącej z wytłoków winogron. W przypadku karbonizatów nie odnotowano istotnych różnić w wartości Ea w zależności od temperatury procesu.

EN

The aim of the presented study was to characterize the thermal conversion of biomass wastes such as grape pomace and kiwi branches and the characteristics of chars obtained at 1000°C and 1200°C (anaerobic conditions). The morphology and thermal behavior of the analyzed materials were carried out using SEM-EDAX and TGA methods, respectively. On the basis of thermogravimetric data, the thermal conversion characteristics of raw biomass and biochars were determined. Then, based on the TGA results, kinetic parameters were determined, i.e. activation energy Ea and pre-exponential factor A. Activation energy values obtained for the kiwi branch are higher than the values calculated for biomass from grape pomace. Additionally, in the case of biochars there were no significant differences in the Ea value depending on the process temperature.

16

Fly ash/phenolic resin composite for brake pad application : fabrication, materials and thermal properties

Savetlana Shirley, Lubis Asnawi, Aditya Lingga, Irfan Muhammad, Siadari Dedi, Efendi Gunawan, Yusuf Muhammad, Jefri Hel

Composites Theory and Practice

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2020

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R. 20, nr 3-4

95--101

EN

Nowadays, many parts of automotive components are made of composites. One application of composites is brake lining material in braking systems. Fly ash is waste from burning coal in the power plant industry. Fly ash was added to a polimer matrix to enhance the wear properties of the composite. The appropriate temperature and pressure for composite fabrication were chosen from the composite which has the highest hardness. The addition of 30 wt.% fly ash to the phenolic resin matrix resulted in the lowest specific abrasion of the composite. Additions of graphite, iron powder and nitrile butadiene rubber increased the specific abrasion of the fly ash/phenolic resin composite. Scanning electron microscope micrographs showed the distribution and agglomeration of the particles in the phenolic resin matrix. The addition of fly ash to the phenolic resin matrix also increased the temperature resistance of the composite. Thermogravimetric analysis shows that the starting temperatures for decomposition of the composite constituents shifted to higher temperatures as the fly ash content increases.

17

Synthesis, growth and characterization of semiorganic nonlinear optical single crystal bis(thiourea) barium nitrate (BTBN) for frequency conversion

Anbarasi A., Kumar S.M. Ravi, Raj M. Packiya, Sundar G.J. Shanmuga, Ganapathy M., Kubendiran T., Varalakshmi S.

Materials Science Poland

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2019

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Vol. 37, No. 3

381--388

EN

A novel semiorganic nonlinear optical (NLO) crystal, bis(thiourea) barium nitrate (BTBN) was synthesized and grown by slow evaporation method. Structure of the new crystalline compound was confirmed by single crystal X-ray diffraction analysis and it showed that BTBN belongs to orthorhombic crystal system. The crystalline nature of the BTBN was confirmed by powder X-ray diffraction study. Important functional groups of BTBN were identified by FT-IR spectroscopic analysis. UV-Vis-NIR spectral study showed that the grown crystal is transparent in the entire visible region with low cut off wavelength of 304 nm. BTBN exhibits a SHG efficiency which is nearly 2.38 times higher than that of KDP. The BTBN crystal has high mechanical strength and belongs to soft category, which was confirmed by micorhardness study. The thermal stability of BTBN was determined from TGA and DTA thermal study which revealed that the BTBN crystal has thermal stability up to 243.1 °C. The surface properties and presence of elements was analyzed by SEM and EDAX study, respectively.

18

Termograwimetria i analiza gazowa. Cz. 5, TGA-mikro GC/MS

Fedelich Nicolas

LAB Laboratoria, Aparatura, Badania

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2019

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R. 24, nr 4

28--32

PL

W poprzednich artykułach tej serii poświęconych termograwimetrii i analizie uwolnionych gazów, omówiliśmy analizę termograwimetryczną (TGA) sprzężoną on-line ze spektroskopią w podczerwieni z transformacją Fouriera (FTIR), spektrometrią masową (MS) oraz chromatografią gazową z detektorem MS (GC/MS). W niniejszym artykule, ostatnim w tej serii, omówimy analizę TGA sprzężoną z mikrochromatografią gazową (mikro GC) opcjonalnie wyposażoną w spektrometr masowy.

19

Influence of liming on kinetics of sewage sludge pyrolysis

Stolarek Paweł, Ledakowicz Stanisław, Ślęzak Radosław

Ecological Chemistry and Engineering. S

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2019

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Vol. 26, nr 1

175--188

EN

Thermogravimetry (TG) is the fast and reliable method for characterization of thermal decomposition of any material and in particular to determine the kinetics of pyrolytic decomposition of sewage sludge. Two types of sewage sludge with and without addition of lime were investigated from kinetic point of view. For TG analysis samples of selected sewage sludge were heated under the inert atmosphere of argon with constant heating rate from 303 to 1273 K; the three heating rate β = 5, 10 and 20 K/min were chosen. The iso-conversion methods of Friedman and Ozawa-Flynn-Wall were employed for analysis of TG results. As the sewage sludge decomposition is very complex process it cannot be described by a simple stoichiometric equation, therefore the so called lumping of reactions in the selected temperature ranges were used with detailed principles arising from visual analysis of DTG curve. The deconvolution of DTG curves performed according to Fraser-Suzuki asymmetric profile allowed the identification of number of lumps and their contribution to the overall mass loss. So the decomposition of sewage sludge with lime addition could be described with five groups of reactions while the one without lime by means of six lumps. The thermal decomposition of sewage sludge was assumed to proceed according to the scheme of parallel concurrent independent reactions of n-th order. The values of the apparent activation energies at different constant values of conversion degrees were determined by the iso-conversion analysis. To estimate the kinetic parameters the non-linear regression with Levenberg-Marquart optimization procedure was used. The kinetic parameters such as activation energy, pre-exponential factor, reaction order and fraction of total mass loss associated with a given reaction were determined. The impact of sewage sludge liming revealed in essential differences of pyrolysis products and pyrolysis kinetics of limed sludge and without lime one was highlighted.

20

A comparison of thermogravimetric characteristics of fresh and used engine oils

Kozak Miłosław

Combustion Engines

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2019

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R. 58, nr 3

289--292

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.