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Wyświetlanie 1-15 z 104
Tytuł:
Analysis of the Thermal and Magnetic Properties of Amorphous Fe61Co10Zr2.5Hf2.5Me2W2B20 (Where Me = Mo, Nb, Ni Or Y) Ribbons
Autorzy:
Gruszka, K.
Nabiałek, M.
Szota, M.
Bloch, K.
Gondro, J.
Pietrusiewicz, P.
Sandu, A. V.
Mustafa Al Bakri, A. M.
Walters, K.
Walters, S.
Garus, S.
Dośpiał, M.
Mizera, J.
Powiązania:
https://bibliotekanauki.pl/articles/355886.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal stability
magnetic properties
Opis:
The paper presents the results of structural and magnetic properties and thermal stability for a group of functional materials based on Fe61Co10Zr2.5Hf2.5Me2W2B20 (where Me = Mo, Nb, Ni or Y). Samples were obtained in the form of ribbons using melt-spinning method. The X-ray diffraction patterns of investigated samples confirmed their amorphous structure. Based on the analysis of DSC curves characteristic temperatures: glass forming temperature (Tg), crystallization temperature (Tx) and temperature range of the supercooled liquid ΔTx were determined. Small addition of transition metals elements has strong influence on magnetic and thermal parameters of studied materials. The comprehensive studies revealed that in terms of magnetic properties the Ni-addition resulted in highest reduction in coercivity and anisotropy field.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 641-644
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and characterization of epoxy methacrylate of (E)-1,3-bis(4-hydroxyphenyl)prop-2-en-1-one and its jute/glass composites
Autorzy:
Thanki, J. D.
Parsania, P. H.
Powiązania:
https://bibliotekanauki.pl/articles/1190152.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
epoxy methacrylate
thermal stability
composites
hydrolytic stability
Opis:
Epoxy methacrylate of (E)-1,3-bis(4-hydroxyphenyl)prop-2-en-1-one (EMC) has been synthesized by condensing 1 equivi. (318g) epoxy resin of (E)-1,3-bis(4-hydroxyphenyl)prop-2-en-1-one and 2.1 equivi. (181g) methacrylic acid using 10 ml triethyl amine as a catalyst, 2.5 g hydroquinone as an inhibitor and 350 ml tetrahydrofuran as a solvent at reflux temperature for 1-7 h. Styrene was used as a reactive diluent. The structure of EMC was supported by FTIR and 1H NMR techniques. EMC showed endothermic transition at 118 °C and 307 °C, respectively due to melting and crosslinking followed by decomposition reaction and EMCS showed endothermic transitions at 81 °C and 255 °C due to branched and uncrosslinked EMCS and some physical change. EMC and EMCS are thermally stable up to about 265 and 332, respectively. EMC followed two steps degradation kinetics, while EMCS followed single step degradation kinetics. Jute and glass composites of EMCS were fabricated by hand lay-up technique followed by compression molding under 20 bar pressure and at 120 °C for 4 h. J-EMCS and G-EMCS showed 22.7 and 182 MPa tensile strength; 10.9 and 156.5 MPa flexural strength; 3.1 and 1.6 kV mm-1 electric strength; and 2.2 x 1012 and 2.8 x 1011 Ohm cm volume resistivity. Both J-EMCS and G-EMCS showed excellent hydrolytic stability even in harsh acidic and saline environments and also in boiling water. Observed equilibrium water content at 35 °C for J-EMCS and G-EMCS in water, 10% of aq. NaCl, and 10% of aq. HCl are 8.8, 10.8, and 8.7% ; 5.8, 4.6, and 4.7%, respectively. The composites may be useful for low load bearing housing units, and in electrical, electronic and marine fields.
Źródło:
World Scientific News; 2016, 42; 182-196
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of different lignin systems in polymers: mechanical properties and thermal stability
Autorzy:
Hasan, Gvlmira
Musajan, Dilhumar
Hou, Gong-bo
He, Mingyu
Li, Ying
Yimit, Mamatjan
Powiązania:
https://bibliotekanauki.pl/articles/779443.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
lignin
mechanical properties
thermal stability
polymer
Opis:
Lignin was used to study the mechanical properties and thermal stability of polymers. The lignin was blended with three kinds of polymers, and the addition of lignin was 0.5 wt%. Under the condition of thermal oxidation, the thermal stability of lignin/polymer samples varies with the structure of lignin. The effects of lignin on the mechanical properties and thermal stability of the polymers were investigated by oxidation induction time (OIT), rheological properties, mechanical properties and differential scanning calorimetry (DSC). The results show that the effect of lignin on the thermal properties of polymer samples is 2~3oC. It can be inferred that lignin can effectively improve the interaction between polymer molecular chain segments, and improve the crystallization rate and rigidity to a certain extent, so it can be seen that lignin has good compatibility and thermal stability.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 4; 10-16
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multicomponent ceramic materials on the basis of PZT for the production of piezoelectric resonators
Autorzy:
Bochenek, D.
Surowiak, Z.
Gavrilyachenko, S. V.
Kupriyanov, M. F.
Powiązania:
https://bibliotekanauki.pl/articles/176898.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PZT
piezoelectric transducers
resonance frequency
thermal stability
Opis:
Investigations on the influence of the PbTiO3 content on the crystalline and domain structure of PZT-based four-component solid solutions have been performed. It has been shown that there is a close relation between the structure and temperature stability of the resonance frequency (fr) of the fabricated piezoceramic transducers. Better and more stable results have been obtained by doping and modifying the basic chemical composition obtaining Pb(Zr1-x Tix)O3. The compositions with minimal Δ fr / fr, within the temperature range T = 213–358 K (in relation to room temperature Tr = 293 K), exhibited (i) the smallest internal friction (Q-1m), (ii) the highest mechanical quality (Qm), (iii) high values of spontaneous deformation of the elementary cell (δT and δRe), (iv) the complex a-c-domain structure in the tetragonal phase (T) and the simple domain structure in the rhombohedral phase (Re). The practical result of the present work was the fabrication of piezoceramic electric band filters exhibiting Δ fr / fr < 0.2% and a high mechanical quality factor (Qm = 3225).
Źródło:
Archives of Acoustics; 2005, 30, 1; 87-107
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Path to ε-HNIW with Reduced Impact Sensitivity
Autorzy:
Elbeih, A.
Husarova, A.
Zeman, S.
Powiązania:
https://bibliotekanauki.pl/articles/358508.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HNIW
crystallization
thermal stability
impact sensitivity
SEM
Opis:
New purification method was applied to obtain epsilon HNIW (ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, ε-HNIW) which has low impact sensitivity. The method is based on removing the impurities from a solution of alpha HNIW (ε-HNIW) by a chemical reaction to obtain pure epsilon form. For comparison, selected different published methods for recrystallization of HNIW to obtain the epsilon form were studied. All the selected methods are based on solvent-antisolvent technique. The optimum parameters, such as type of solvent and anti-solvent, volume ratio of solvent to anti-solvent, rate of addition, speed of stirring, etc., were applied to enhance the crystal size and shape of ε-HNIW. Checking the polymorphs of the obtained HNIW was done by Fourier transform infrared spectroscopy (FTIR). The thermal stability of the prepared samples was studied by using differential thermal analysis technique (DTA). Qualitative analysis of the crystal size and shape was done using scanning electron microscope (SEM) devise. Quantitative measurement of the crystals sizes for the studied samples was determined by Laser scattering particle size distribution analyzer. Impact sensitivity was measured by falling hammer test. The results indicate that all the applied methods of recrystallization give ε-HNIW. The impact sensitivity of HNIW decreases by obtaining small particles with regular shape. All the used published methods produce ε-HNIW with higher impact sensitivity than other nitramines. While the obtained crystals from the new method has regular smooth surface, with small particle size and its impact sensitivity is lower than RDX and HMX.
Źródło:
Central European Journal of Energetic Materials; 2011, 8, 3; 173-182
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Properties of RDX-Nitrocellulose Microspheres
Autorzy:
Shi, X.
Wang, J
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/358363.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
RDX
nitrocellulose
flash vaporization process
thermal stability
Opis:
A new insensitive explosive based on RDX and with Nitrocellulose (NC) as binder has been prepared using a flash vaporization process. Scanning electron microscopy was used to characterize the morphology and particle size of the resulting RDX-NC microspheres. X-ray photoelectron spectroscopy, Differential Scanning Calorimetry, impact sensitivity, vacuum stability and burning rate of raw RDX, RDX-NC and RDX-1 were also used to characterize the explosive. The RDX-NC microspheres were found to have a fibrous surface. The microspheres ranged in size from 0.5 μm to 4 μm. The NC formed a coat on the surface of the RDX. The activation energies of raw RDX, RDX-1 and RDX-NC were found to be 200.8 kJ·mol−1, 183.9 kJ·mol−1 and 187.2 kJ·mol−1, respectively. The drop heights of raw RDX, RDX-1 and RDX-NC were found to be 21.3 cm, 51.7 cm and 82.9 cm, respectively. The friction sensitivity of RDX-NC was lower than that of raw RDX and RDX-1. In the vacuum stability test, the volumes of evolved gas from raw RDX, RDX-1 and RDX-NC were 0.12 mL·g−1, 0.12 mL·g−1, and 0.09 mL·g−1, respectively. The burning rates of RDX-NC-based propellants were higher than that of RDX-1 and raw RDX based propellants at 5-15 MPa. The burning rate pressure exponent of RDX-NC based propellants is 0.9929 at 40-200 MPa.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 4; 871-881
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of polar plasticizers on the characteristics of selected cyclic nitramines
Autorzy:
Elbeih, A.
Zeman, S.
Pachman, J.
Powiązania:
https://bibliotekanauki.pl/articles/358627.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic materials
polymers
sensitivity
combustion
thermal stability
Opis:
Dioctyl sebacate (DOS) is a plasticizer used with oily material for the softening of polyisobutylene binder (PIB) to form a polymeric matrix. This matrix was used for the preparation of various plastic explosives. The following energetic cyclic nitramines were used as explosive fillers: BCHMX (cis-1,3,4,6- tetranitrooctahydroimidazo [4,5 d]imidazole), ε-HNIW (ε-2,4,6,8,10,12- hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane), RDX (1,3,5-trinitro-1,3,5- triazacyclohexane), and HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane). For comparison, Fluorel binder was used for the preparation of several plastic bonded explosives (PBXs) based on the same selected explosives. Impact and friction sensitivities of the prepared samples and the pure explosive fillers were measured. The thermal stability was studied using differential thermal analysis (DTA). High performance liquid chromatography (HPLC) was used to detect the presence of BCHMX dissolved in dioctyl sebacate (DOS). The heat of combustion of the prepared samples and of the pure explosive fillers was measured using a bomb calorimetry. The results show that PIB softened by plasticizer (DOS) has a greater positive effect on decreasing the impact sensitivity of the studied pure explosives than Fluorel binder. On the other hand, the plasticizer acts as a solvent for the energetic materials and decreases the decomposition temperature of these plastic explosives.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 3; 339-349
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A New Thermally-stable Insensitive High Explosive:N,N′-Bis(1,2,3,4-tetrazol-5-yl)-4,4′-diamino-2,2′,3,3′,5,5′,6,6′-octanitroazobenzene (BTeDAONAB)
Autorzy:
Mousavi, S.
Esmaeilpour, K.
Keshavarz, M. H.
Powiązania:
https://bibliotekanauki.pl/articles/951499.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
synthesis
BTeDAONAB
sensitivity
thermal stability
high explosive
Opis:
A novel high performance explosive compound, N,N′-bis(1,2,3,4-tetrazol5-yl)-4,4′-diamino-2,2′,3,3′,5,5′,6,6′-octanitroazobenzene( BTeDAONAB), is introduced which is a thermally stable, insensitive high explosive. The presence of −NH2, −N=N− groups and the tetrazole ring simultaneously in the BTeDAONAB unit surprisingly increases its thermal stability. For the identification and characterization of BTeDAONAB, different analytical techniques have been used, including melting point, IR, 1H NMR, 13C NMR spectroscopy, elemental analysis, differential thermal analysis (DTA), thermogravimetry (TG), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The sensitivity and detonation properties of BTeDAONAB were compared with 2,4,6-triamino1,3,5-trinitrobenzene (TATB) and N,N′-bis(1,2,4-triazol-3-yl-)-4,4′-diamino2,2′,3,3′,5,5′,6,6′-octanitroazobenzene (BTDAONAB), two well-known, thermally stable, insensitive high explosives, as well as hexanitrostilbene (HNS). These studies show that BTeDAONAB has favorable thermal stability with high performance.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 4; 455-465
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication and Investigation of Thermal and Wear Properties of Zinc Novel Coatings Reinforced with Nano-Al2O3 and Cr2O3 Particles
Autorzy:
Popoola, A. P. I.
Malatji, N.
Fayomi, O. S. I.
Powiązania:
https://bibliotekanauki.pl/articles/356056.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microstructure
corrosion
nanocomposite coatings
thermal stability
tribology
Opis:
The study of the thermal, wear and corrosion properties of developed nanocomposite coatings of Zn-Al2O3 and Zn-Cr2O3 was carried out. The coatings were produced by electrodeposition technique from chloride acidic bath. Laboratory tube furnace was used for the thermal analysis. The wear test was performed using CETR tribo-tester dry reciprocating tester. The hardness properties were investigated using diamond base Dura microhardness tester. Scanning electron microscope (SEM) affixed with energy dispersive spectrometry was used to study the morphological characteristics, before and after wear deformation. The corrosion degradation behavior was observed using linear polarization technique in 3.5% NaCl. In all the interaction, the effects of the incorporated Al2O3 and Cr2O3 nanoparticulates on zinc rich coatings were found to have an excellent influence on the wear, corrosion and thermal stability properties. The fabrication and properties exhibited by the alloys were therefore found to be satisfactory and shows good predictability and applicability.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1671-1676
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Treatments Of Natural Fibres In Fibre Reinforced Composites: A Review
Autorzy:
Seisa, Keolebogile
Chinnasamy, Vivekanandhan
Ude, Albert U.
Powiązania:
https://bibliotekanauki.pl/articles/2171957.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
hydrophilic
thermal stability
hydrophobic
amorphous
morphological properties
Opis:
The use of natural fibres in fibre-reinforced composites comes with drawbacks. They are highly hydrophilic, leading to high moisture absorption and poor interfacial adhesion in matrix-reinforcement bonds. This affects the fibres’ thermal stability as well as mechanical properties, hence limiting their wider application. This paper reviewed different ways in which natural fibres have been treated to improve hydrophobicity, reinforcement-matrix interfacial adhesion and thermal stability. It will investigate. among others, treatments like alkali, acetylation, bleaching, silane, benzoylation and plasma, which have been found to improve fibre hydrophobicity. The literature reviewed showed that these methods work to improve mechanical, chemical, and morphological properties of natural fibres by removing the amorphous surface, thus allowing for more efficient load transfer on the fibre-matrix surface. Studies in the literature found alkali treatment to be the most common surface modification treatment due to its simplicity and effectiveness. However, plasma treatment has emerged due to its lower processing time and chemical consumption. A comparative analysis of other improved properties was also investigated.
Źródło:
Fibres & Textiles in Eastern Europe; 2022, 2 (151); 82--89
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Thermal Stability of CrCN Coatings Deposited on Nitrided Substrates Using Modulated Temperature Thermodilatometry
Autorzy:
Mydłowska, K.
Myśliński, P.
Szparaga, Ł.
Ratajski, J.
Gilewicz, A.
Jędrzejewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/352462.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
antiwear coatings
nitriding
residual stress
thermal stability
thermodilatometry
Opis:
The aim of the research was to investigate the influence of nitriding of the substrate made of 42CrMo4 steel on thermal stability of the antiwear CrCN coating deposited on its surface using Cathodic Arc Evaporation method. Samples of non-nitrided and nitrided substrate/CrCN coating systems were tested with Modulated Temperature Thermodilatometry, which program included system annealing in 26 h, temperature of 290°C and argon atmosphere. Recorded during tests, changes in substrate elongation in response for changes of sample temperature, enabled qualitative determination of changes in stress states in the coatings as a result of samples annealing. Annealing of the system with nitrided substrate resulted in smaller change in residual stress in coating than for the system with non-nitrided substrate, which can indicate its better thermal stability. Values of residual stresses in coatings calculated by sin2ψ method before and after annealing on the basis of tests performed using X-Ray diffraction, agree with results of dilatometric tests.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 771-776
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of HMX/Estane Nanocomposites
Autorzy:
Shi, X.
Wang, J.
Li, X.
An, Ch.
Powiązania:
https://bibliotekanauki.pl/articles/358274.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
Estane 5703
spray drying
nanocomposites
thermal stability
Opis:
A new insensitive explosive based on octahydro-1,3,5,7-tetranitro1,3,5,7-tetrazocine (HMX) was prepared by spray drying using Estane 5703 as a binder. Scanning electron microscopy was used to characterize the morphology and particle size of the HMX/Estane 5703 nanocomposites. The composites were analyzed by X-ray diffractometry and differential scanning calorimetry and their impact sensitivity was determined. For comparison, raw HMX was also tested using these three methods. The nanocomposite morphology was found to be microspherical (1 to 8 μm diameter) and composed of many tiny particles, 30 to 150 nm in size. The crystal type of the HMX/Estane 5703 nanocomposites was unchanged. The activation energy, self-ignition temperature and average drop height of the raw HMX were 515.66 kJ·mol-1, 278.63 °C and 18.4 cm, respectively. In comparison, the corresponding values for the HMX/Estane 5703 nanocomposites were 488.92 kJ·mol-1, 279.3 °C and 75.4 cm, respectively.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 3; 433-442
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure and Plasticity of Hot Deformed 5083 Aluminum Alloy Produced by Rapid Solidification and Hot Extrusion
Badania mikrostruktury i plastyczności odkształcanego na gorąco szybko-krystalizowanego i wyciskanego stopu aluminium 5083
Autorzy:
Tokarski, T.
Wzorek, Ł.
Dybiec, H.
Powiązania:
https://bibliotekanauki.pl/articles/356129.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rapid solidification
Al-Mg alloy
thermal stability
superplasticity
Opis:
The objective of the present study is to analyze the mechanical properties and thermal stability for rapidly solidified and extruded 5083 aluminum alloy (RS). Compression tests were performed in order to estimate flow stress and strain rate sensitivity relation for 5083 alloy in the temperature range of 20°C to 450°C. For the comparison purposes, conventionally cast and extruded industrial material (IM) was studied as well. Deformation tests performed at room temperature conditions show that rapidly solidified material exhibits about 40% higher yield stress (YS=320 MPa) than conventionally cast material (YS=180 MPa), while the deformation at 450°C results in significant decrease of flow stress parameters for RS material (YS=20 MPa) in comparison to IM material (YS=40 MPa). Strain rate sensitivity parameter determined for high temperature conditions indicates superplasticity behavior of RS material. Structural observations show that under conditions of high-temperature deformation there are no operating recrystallization mechanisms. In general, grain size below 1μm and size of reinforcing phases below 50 nm is preserved within the used deformation temperature range.
Celem niniejszej pracy było zbadanie własności mechanicznych oraz stabilności termicznej szybkokrystalizowanego a następnie wyciskanego stopu aluminium 5083. Testy ściskania przeprowadzone w zakresie temperatur od 20°C do 450°C przy dwóch różnych prędkościach odkształcenia pozwoliły na wyznaczenie charakterystyk naprężenia płynięcia materiału oraz jego czułości na prędkość odkształcenia w funkcji temperatury. Wyniki odniesiono do wyciskanego w identycznych warunkach, konwencjonalnie odlewanego materiału (IM - industrial material) o tym samym składzie chemicznym. Uzyskane dane wskazują, ze szybkokrystalizowany materiał posiada w temperaturze pokojowej ok. 40% wyższa granice plastyczności wynosząca 320 MPa w stosunku do materiału odlewanego - 180 MPa. Natomiast w najwyższej temperaturze deformacji naprężenie uplastyczniające stopu RS jest dwukrotnie niższe niż dla materiału IM (40 MPa dla materiału odlewanego w porównaniu z 20 MPa dla materiału szybko krystalizowanego). Wyznaczony w najwyższej temperaturze parametr czułości na prędkość odkształcenia dla stopu RS (Rapid Solidification) osiąga wartości zbliżone do 0,3 co wskazuje na nadplastyczność tego materiału. Przeprowadzone badania elektrono-mikroskopowe wskazują na brak aktywnych mechanizmów odbudowy struktury. Zarówno wielkość ziarna w materiale RS będąca na poziomie poniżej 1μm jak i wielkość faz umacniających nie przekraczających 50 nm nie ulegała zmianie w całym zakresie stosowanych temperatur.
Źródło:
Archives of Metallurgy and Materials; 2012, 57, 4; 1253-1259
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal and kinetic analysis of pure and contaminated ionic liquid: 1-butyl-2.3-dimethylimidazolium chloride (BDMIMCl)
Autorzy:
Muhammad, A.
Powiązania:
https://bibliotekanauki.pl/articles/949468.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ionic liquid
thermal stability
kinetic analysis
activation energy
Opis:
In this research work, thermal decomposition and kinetic analysis of pure and contaminated imidazolium based ionic liquid (IL) has been investigated. As thermal decomposition and kinetics evaluation plays a pivotal role in effective process design. Therefore, thermal stability of pure 1-butyl-2,3-dimethylimidazolium chloride (BDMIMCl) was found to be higher than the sample of IL with the addition of 20% (wt.) NH4Cl as an impurity. The activation energy of thermal degradation of IL and other kinetic parameters were determined using Coats Redfern method. The activation energy for pure IL was reduced in the presence of NH4Cl as contaminant i.e., from 58.7 kJ/mol to 46.4 kJ/mol.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 2; 122-125
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multifunctional oligoetherols and polyurethane foams with carbazole ring
Autorzy:
Lubczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/778805.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
carbazole
sorbitol
hydroxyalkylation
oligoetherols
thermal stability of foams
Opis:
A new method of preparation of multifunctional oligoetherols containing carbazole ring is presented. The oligoetherols were obtained in the reaction of 9-(2,3-epoxypropyl)carbazole with sorbitol and oxiranes like ethylene and propylene oxide. The structure of obtained oligoetherols was determined by IR, H-NMR and MALDI-ToF spectroscopies. Physical properties of the products render them good candidates for preparing polyurethane foams. The foams were obtained and their properties were examined. It has been found that the foams are rigid at room temperature and their apparent density was 50–70 kg/m3. The water uptake was low, maximum to 6.5 mass%. Obtained foams have high thermal resistance. Dynamic thermal analysis of these foams showed that 5% mass loss was initiated at 250–300oC, while temperature of 50% mass loss was 370–404oC. Concomitantly the increase of compression strength was observed.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 1; 120-126
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 104

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