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Tytuł:
Influence of nanosilver on thermal stability of chitosan
Autorzy:
Białas, Sylwia
Mucha, Maria
Powiązania:
https://bibliotekanauki.pl/articles/1035214.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
nanosilver
thermal degradation
Opis:
Nanoadditives for polymers have many valuable features: e.g. the ability to change the properties of polymers: mechanical strength, stability and heat resistance and resistance to radiation. These properties make them an interest in recent years. Studies of polymer composites with nanoadditives leads to discovering more, unique types of nanoadditive interactions on a structure and properties of the polymer. One of the most widely used nanoadditive is nanosilver, which have antibacterial and antifungal properties. An important aspect is thus to investigate the effect of this additive on thermal stability of the polymer composite. The aim of this study was to investigate the effect of nanosilver on the thermal stability and properties of chitosan. Chitosan composites with nanosilver in the form of films with a thickness of 10-30um and the content of silver 0.5 and 1% was obtained by casting. In order to study the thermal stability samples were subjected to a temperature of 120°C (time 0-90h). Studies on influence of nanosilver on the thermal stability of the polymer was performed using infrared spectroscopy (FTIR). This allows to observe changes in the chemical structure of polymer. The changes in the major functional groups was observed: 1420cm-1(bending vibration of -C-H group), 1577cm-1 (bending vibrations of the amine group-NH2), 1655cm-1 (vibrations of C=O in amide group). Mechanical strength test of chitosan composites subjected to high temperature was also performed. Tensile tests (using the Instron 5325 apparatus) were conducted to determine changes in values of Young's modulus, maximum stress and elongation at break. The study showed an effect of the presence of nanosilver on the structural and mechanical properties of chitosan. Nanosilver improves the thermal stability of studied functional groups of chitosan.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2013, 18, 18; 85-92
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of the Thermochemical Degradation of PET: An Alternative Method of Recycling
Autorzy:
Cruz, José Nolasco
Martínez, Karla Donjuan
Zavariz, Álvaro Daniel
Hernández, Irma Pérez
Powiązania:
https://bibliotekanauki.pl/articles/2173350.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
thermal degradation
PET
polyethylene terephthalate
recycling
Opis:
Plastics play an important role in our lives due to their versatility, lightness and low production cost. They can be found in almost every industry such as automotive, construction, packaging, medical, and engineering applications among others. Polyethylene terephthalate (PET) is one of the most consumed plastics worldwide in the packaging sector, which is why its useful life is usually very short, causing serious problems due to high disposal in the environment and urban landfills. The thermochemical degradation of PET has been studied by some researchers and it has been found that its degradation products are of high added value, which is why this work focuses on presenting the results obtained in the literature.
Źródło:
Journal of Ecological Engineering; 2022, 23, 9; 319--330
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The proposal of evaluation of selected thermal-degradation and environmental characteristics of wood modified treatment. Part 1: Determination of selected thermal-degradation characteristics
Propozycja oceny degradacji termicznej i oceny środowiskowej. Część 1. Ocena charakterystyki degradacji termicznej
Autorzy:
Ruzinska, E.
Mitterova, I.
Jablonski, M
Powiązania:
https://bibliotekanauki.pl/articles/8721.pdf
Data publikacji:
2014
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
environment degradation
thermal degradation
wood
surface
treatment
risk substance
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2014, 87
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal degradation of double crosslinked hydrogel chitosan membranes
Autorzy:
Pieróg, Milena
Ostrowska-Czubenko, Jadwiga
Gierszewska-Drużyńska, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/1035381.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
DSC
FTIR
chitosan membrane
thermal degradation
thermogravimetry
Opis:
The thermal degradation behaviour of uncrosslinked and crosslinked chitosan membranes were studied by means of dynamic thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) over the temperature range 25-500ºC in nitrogen atmosphere. Modified chitosan membranes were prepared using a crosslinking method based on covalent crosslinking of chitosan with glutaraldehyde and subsequent ionic crosslinking with sodium citrate, sulfuric acid, sulfosuccinic acid and tripolyphosphate, respectively. Chemical structure of modified chitosan membranes before and after their thermal degradation was characterized by FTIR spectroscopy. Both TGA and DSC experiments as well as spectral results (FTIR spectra of thermal degradation residues) indicated some differences in the mechanism of thermal degradation of uncrosslinked and crosslinked chitosan membranes.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2012, 17; 71-78
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transition Time of Ultrasonic Wave as a Tool of Quality Evaluation of Layered Polymer Composites
Autorzy:
Szymiczek, M.
Powiązania:
https://bibliotekanauki.pl/articles/177341.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic testing
diagnostics
polymer composites
thermal degradation
ageing-fatigue degradation
Opis:
Observation of behaviour phenomena of ultrasonic waves in an object allows for quality assessment, identification and location of discontinuity. Physical nature of acoustic processes is based on propagation of mechanical waves constituting a disturbance of equilibrium of the state of material. The acoustic proces identified by selected characteristics can be a source of information about state of material, its structure, and properties, which is particularly important for systems exhibiting anisotropy properties, and such are layered polymer composites. They are special materials because their properties depend greatly on the manufacturing technology. Therefore, while conducting acoustic tests which use the influence of elastic properties and homogeneity of material structure for propagation of sound waves the adopted method of measuring characteristics which identifies propagation of ultrasonic wave phenomenon is of particular importance. The aim of the work was quality evaluation of layered polymer composites made by Winding and press moulding by the method of echo and C-scan, using head Phased Array. Composites have been tested by thermal and fatigue degradation. Quality evaluation has been made based on the transition time of the ultrasonic wave and the bending strength.
Źródło:
Archives of Acoustics; 2017, 42, 3; 499-506
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermochemical Degradation of Polypropylene: Energy and Exergy Analysis in a Tubular Reactor
Autorzy:
Cruz, Jose Nolasco
Hernández, Irma Pérez
Villalobo, María de Lourdes Castellanos
Henández, Angélica Pérez
Ávila, Juan José López
Powiązania:
https://bibliotekanauki.pl/articles/24201766.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
tubular reactor
exergy
energy
PP
polypropylene
thermal degradation
Opis:
One method to evaluate the energy behavior is energy and exergy analysis. These analyses applied to waste-to-energy conversion technologies provide the information on operating conditions, facilitating energy optimization processes. In this study, an energetic and exergy analysis was used on the thermochemical degradation process of polypropylene in a tubular reactor at 600 °C with a speed of 15 °C min-1. The experimental data used in this work were taken from the study by Parku et al. (2020). According to the results, energy efficiencies of up to 43% and exergy efficiencies of 38% were achieved, and it was also observed, according to what was reported, that the products obtained from pyrolysis contain a high calorific value and can be used as alternative fuels.
Źródło:
Journal of Ecological Engineering; 2023, 24, 5; 14--21
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal behavior and kinetic decomposition of sweet potato starch by non-isothermal procedures
Autorzy:
Liu, Ying
Yang, Liutao
Zhang, Yingzhe
Powiązania:
https://bibliotekanauki.pl/articles/240460.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
starch
kinetic analysis
thermal degradation
activation energy
mechanism
Opis:
In this study, X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry (DSC) method were used to analyze the main characteristics of sweet potato starch, and to analyze the thermal degradation process of sweet potato starch. Specifically, X-ray diffraction to study its structure, thermogravimetric analysis to study the thermal degradation kinetics, and differential scanning calorimetry to study the thermogram of sweet potato starch. The thermal decomposition kinetics of sweet potato starch was examined within different heating rates in nitrogen atmosphere. Different models of kinetic analysis were used to calculate the activation energies using thermogravimetric data of the thermal degradation process. Activation energies obtained from Kissinger, Flynn-WallOzawa, and Šatava-Šesták models were 173.85, 174.87 and 174.34 kJ/mol, respectively. The values of activation energy indicated that the thermal degradation of the sweet potato starch was a single reaction mechanism or the combination of multi-reaction mechanisms. The differential scanning calorimetry analysis show that two decomposition stages were presented: the first at a low temperature involves the decomposition of long chain; and the second at a high temperature represents the scission of glucose ring. This information was helpful to design the processing process of many natural polymers. Thermogravimetric Fourier transform-infrared (TG–FTIR) analysis showed that the main pyrolysis products included water, methane, carbon dioxide, ammonia, and others.
Źródło:
Archives of Thermodynamics; 2019, 40, 4; 67-82
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal degradation process of semi-synthetic fuels for gas turbine engines in non-aeronautical applications
Autorzy:
Sarnecki, Jarosław
Białecki, Tomasz
Gawron, Bartosz
Głąb, Jadwiga
Kamiński, Jarosław
Kulczycki, Andrzej
Romanyk, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/258646.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
gas turbine engine
thermal stability
bio-fuels
thermal degradation process
Opis:
This article concerns the issue of thermal degradation process of fuels, important from the perspective of the operation of turbine engines, especially in the context of new fuels/bio-fuels and their implementation. The studies of the kerosenebased jet fuel (Jet A-1) and its blends with synthetic components manufactured according to HEFA and ATJ technology, were presented. Both technologies are currently approved by ASTM D7566 to produce components to be added to turbine fuels. Test rig investigations were carried out according to specific methodology which reflects the phenomena taking place in fuel systems of turbine engines. The mechanism of thermal degradation process was assessed on the basis of test results for selected properties, IR spectroscopy and calculation of activation energy. The results show that with the increase of the applied temperature there is an increment of the content of solid contaminants, water and acid for all tested fuels. Thermal degradation process is different for conventional jet fuel when compared to blends, but also semi-synthetic fuels distinguished by different thermal stability depending on a given manufacturing technology.
Źródło:
Polish Maritime Research; 2019, 1; 65-71
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal stability of chitosan nanocomposites containing tio2 and organo-modified montmorillonite
Autorzy:
Książek, Sylwia
Mucha, Maria
Powiązania:
https://bibliotekanauki.pl/articles/1034832.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
organo-modified montmorillonite
thermal degradation
titanium dioxide nanoparticles
Opis:
The aim of this work was to investigate the effect of different nanoparticles (TiO2 and organically modified montmorillonite MMT) on thermal stability of chitosan thin films (obtained by casting) and to compare with previously studied- CuO and Ag effect. Thermal degradation was carried out in air atmosphere at 140°C up to 100 hours. Various functional groups of chitosan have a different susceptibility to degradation. The influence of nanoparticles amount on degradation of selected structural groups of chitosan was calculated. It was proved, that elongation at break of chitosan sample and its nanocomposites with TiO2 and organically modified montmorillonite decrease rapidly after 20h of thermal degradation. Moreover, as is clear from FTIR studies, that TiO2 nanoparticles enhance the resistant of the -C-O-C- bond responsible for chain scission of chitosan due to thermal degradation. An opposite effect is observed in a case of MMT, where the chain scission of -C-O-C- bond is higher than for pure chitosan. Another effect of nanoparticles are observed in destruction of unstable amine group (-NH3 band at 1560 cm-1) and formation of the amide group (band at 1650 cm-1). In this case both nanoadditives accelerate the decomposition of amine group and the formation of amide group in higher extent in comparison to pure chitosan.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2015, 20; 122-129
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polylactide Used as Filment in 3D Printing – Part 1: FTIR, DRIFT and TG-DTG Studies
Autorzy:
Grabowska, Beata
Kaczmarska, Karolina
Cukrowicz, Sylwia
Mączka, Elżbieta
Bobrowski, Artur
Powiązania:
https://bibliotekanauki.pl/articles/1445019.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
polylactide
3D printing technology
thermal degradation
FTIR
TG-DTG
Opis:
A short literature review was undertaken in terms of the structure, properties and applications of polymers, including those commonly used in 3D printing. The research part included the structural and thermal analysis of polylactide (PLA), which is an example of an extensively used polymer in the developing 3D technology. Special attention was paid to the comparison of structure and thermal stability of two different (from various producers) polylactide samples. The research, involving such analytical methods as infrared spectroscopy (FTIR) and diffuse reflectance infrared spectroscopy (DRIFT), allowed the comparison of the structure of the two PLA samples considered. The determination of the temperature range in which changes related to PLA thermodestruction occur was a result of the performed thermoanalytical research (DRIFT, TG-DTG). Thermal studies also allowed to establish the temperature range in which the material does not yet degrade, which is important in the context of future planned research work on polylactide modification to obtain the improvement of the thermal and mechanical properties of PLA-based materials. This research area will be described in the second part of the publication.
Źródło:
Journal of Casting & Materials Engineering; 2020, 4, 3; 48-52
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal degradation of photoreactive solvent-free acrylic pressure-sensitive adhesives based on 2-ethylhexyl acrylate
Degradacja termiczna fotoreaktywnych klejów poliakrylanowych na bazie akrylanu 2-etyloheksylu
Autorzy:
Czech, Z.
Butwin, A.
Powiązania:
https://bibliotekanauki.pl/articles/271166.pdf
Data publikacji:
2010
Wydawca:
Centralny Ośrodek Badawczo-Rozwojowy Aparatury Badawczej i Dydaktycznej, COBRABiD
Tematy:
kleje poliakrylanowe
degradacja termiczna
photoreactive acrylic self-adhesives
thermal degradation
Opis:
The thermal degradation of photoreactive acrylic self-adhesives (PSAs) containing 99.5 wt.% of 2-ethylhexyl acrylate (2-EHA) and 0.5 wt.% unsaturated photoinitiator 4-acryloyloxy benzophenone (ABP) has been performed at 250 degrees of Celsius. The type and amount of the pyrolysis products give important information about the mechanism of thermal degradation of this kind of photoreactive PSAs. It was evaluated using GC-analysis that during the thermal degradation of PSAs based on 2-ethylhexyl acrylate such main thermal decomposition products as 2-ethylhexen-1, 2-ethylhexanol-1, and 2-ethylhexyl (meth)acrylate were formed.
Przeprowadzono termiczną degradację fotoreaktywnych poliakrylanowych klejów samoprzylepnych zbudowanych z 99,5 % wag. akrylanu 2-etyloheksylu (2-EHA) oraz 0,5 % wag. nienasyconego fotoinicjatora 4- akryloilooksybenzofenonu (ABP) w temperaturze 250 stopni Celsjusza. Na podstawie otrzymanych produktów termicznej degradacji przedstawiono możliwy model termicznej degradacji badanych fotoreaktywnych klejów samoprzylepnych. Korzystając z pomocy chromatografii gazowej stwierdzono obecność takich pirolitycznych produktów, jak 2-etyloheksen-1, 2-etyloheksanol-1 oraz (met)akrylan 2-etyloheksylu.
Źródło:
Aparatura Badawcza i Dydaktyczna; 2010, 15, 1; 9-13
2392-1765
Pojawia się w:
Aparatura Badawcza i Dydaktyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Degradation Behaviour and Kinetics of aged TNT-based Melt Cast Composition B
Autorzy:
Singh, Arjun
Sharma, Tirupati Chander
Singh, Vasundhara
Mukherjee, Niladri
Powiązania:
https://bibliotekanauki.pl/articles/358256.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
composition B
thermal degradation
thermogravimetry
Differential Scanning Calorimetry
kinetics
thermodynamic parameters
Opis:
In the present paper, three kinds of aged and freshly prepared 2,4,6-trinitrotoluene (TNT) based Composition B stockpiled, for a period of 20 and 32 years, were investigated for the effect of natural ageing on their thermal degradation behaviour and kinetic parameters. The properties investigated indicated that there was no significant change in the thermal stability of the samples aged under natural environmental conditions. The kinetic parameters were studied by means of the Kissinger method using the peak temperature at maximum reaction rate from DSC data, and the isoconversional Kissinger-Akahira-Sunnose (KAS) and ASTM E689 methods from TGA data. The apparent activation energies calculated by the Kissinger method were 173.8 kJ·mol–1 for fresh, 170.4 kJ·mol–1 for 20 y old and 187.1 kJ·mol–1 for 32 y old Composition B, respectively. The values calculated by the KAS method were found to be in the range 77.2-235.8 kJ·mol–1 for fresh Composition B, 75.7-224.0 kJ·mol–1 for 20 y old and 70.4-196.0 kJ·mol–1 for 30 y old Composition B, respectively. The activation energies obtained from the KAS methods are in good agreement and consistent with the isoconversional ASTM E689 kinetic method. The thermodynamic parameters, such the Gibbs free energy of activation (ΔG#), activation enthalpy (ΔH#) and activation entropy (ΔS#) for the formation of activated complexes were also studied and are discussed.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 3; 360-379
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the thermal degradation process within the steam power plants heat exchangers
Autorzy:
Hajduk, T.
Powiązania:
https://bibliotekanauki.pl/articles/244895.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
steam power plants
fouling of heat transfer surface
thermal degradation determinants
Opis:
The consequence of the deposits presence on the heat transfer surface of the following heat exchangers: shell-and-tube condensers, the regenerative feed water exchangers, are commonly the loss of heat exchanger capacity, owing to the high value of heat conductive resistance of fouling. The process is more often defined as the thermal (heat) degradation of a given heat transfer device. The symptoms of heat degradation are usually defined as the difference between the values of thermal-flow parameters for the current and the reference state. Moreover, this process always entails an increase in the cost of energy conversion, leading to increasing the emission output of greenhouse gases consequently increasing the environmental degradation. It is worth mentioning that deposits settled on the waterside of heat transfer surface could also initiate the process of tubes obliteration. This phenomenon is characteristic for condensers cooled by seawater in particular. Reducing internal diameter of any single heat exchanger pipe by the deposits cause the rise in flow resistance and also reduce the condenser cooling water pump capacity. Ultimately, it leads to the reduction in water flow rate, resulting in an additional increase in the resistance of heat transfer. Furthermore, reducing the flow rate of cooling water causes the enhancement of the fouling settling rate. The paper describes the above-mentioned phenomena and presents the quantitative determinants of the thermal degradation description for heat exchangers based on the results of the author’s own experimental research.
Źródło:
Journal of KONES; 2016, 23, 4; 127-133
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The proposal of evaluation of selected thermal-degradation and environmental characteristics of wood modified treatment. Part 2: Determination of selected environmental characteristics
Propozycja oceny degradacji termicznej i oceny środowiskowej. Część 2. Wyznaczanie wybranych charakterystyk środowiskowych
Autorzy:
Ruzinska, E.
Jablonski, M.
Powiązania:
https://bibliotekanauki.pl/articles/7765.pdf
Data publikacji:
2014
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
thermal degradation
environment degradation
environmental characteristics
wood
treatment
determination
risk substance
surface
wood product
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2014, 87
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal degradation of 17-decarboxy-betanin monitored by LC-MS
Autorzy:
Szot, D.
Starzak, K.
Skopińska, A.
Tuwalska, D.
Wybraniec, S.
Powiązania:
https://bibliotekanauki.pl/articles/115566.pdf
Data publikacji:
2014
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
17-decarboxy-betanin
betacyanins
thermal degradation
17-dekarboksy-betanina
betacyjaniny
degradacja termiczna
Opis:
A thermal stability study on 17-decarboxy-betanin depending on physicochemical process conditions was conducted. 17-decarboxy-betanin is one of betacyanin, natural origin pigments applied in food and pharmaceutical industry instead of artificial colorants. There is a need for searching of new non-toxic natural food components and this is a reason of increasing interest of betacyanins. As most derivatives of betanin obtained by decarboxylation, 17-decarboxy-betanin tends to degrade in the presence of some factors such as increased temperature or other conditions of the reaction environment [1]. This subject was investigated in this study because the stability of the pigments is still a significant issue limiting their wide application. The degradation of 17-decarboxy-betanin during heating in selected solutions: water as well as aqueous solutions of ethanol 50% (v/v), methanol 50% (v/v) and acetonitrile 50% (v/v) at pH in the range 3-8 was tested. As UV-Vis spectra indicate, 17-decarboxy-betanin tends to degrade mostly at pH 3, notwithstanding a type of solution. The products of degradation were identified by LC-DAD-ESI-MS. As a result of incubation at 85°C in different solutions, various mono-, bi- and tridecarboxylated as well as dehydrogenated derivatives were obtained. The dominant product of 17-de-carboxy-betanin degradation is 2,15,17-tridecarboxy-2,3-dehydro-betanin.
Źródło:
Challenges of Modern Technology; 2014, 5, 3; 32-36
2082-2863
2353-4419
Pojawia się w:
Challenges of Modern Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of thermal degradation behavior and kinetics of ABS/PC blend
Autorzy:
Bano, Saira
Ramzan, Naveed
Iqbal, Tanveer
Mahmood, Hamayoun
Saeed, Farhan
Powiązania:
https://bibliotekanauki.pl/articles/778844.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ABS/PC blend
thermal degradation
iso-conversional analysis
activation energy
thermodynamic parameters
Opis:
This work investigated kinetics and thermal degradation of acrylonitrile butadiene styrene and polycarbonate (ABS/PC) blend using thermogravimetric analysis in the range of 25 to 520°C. For thermal degradation of blend, activation energy (Ea) and pre-exponential factor (A) were calculated under various heating rates as 5, 10, 15 and 20°C/min using iso-conversional model-free methods (Kissinger, Flynn-Wall- Ozawa and Friedman). Mass loss of the blend as a function of temperature was plotted as thermogravimetric curve (TG) while derivative values of mass loss were drawn as derivative thermogravimetric (DTG) curve. Using Kissinger method, Ea was 51.4 kJ/mol, while values calculated from FWO and Friedman method were 86–161 and 30–251 kJ/mol respectively. Results showed increasing trend of Ea with higher conversion values indicating different degradation mechanisms at the initial and final stages of the experiment. Thermodynamic parameters such as enthalpy change (ΔH), Gibbs free energy (ΔG) and entropy change (ΔS) were also calculated.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 3; 64-69
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of demineralization on the physiochemical structure and thermal degradation of acid treated indigenous rice husk
Autorzy:
Aslam, U.
Ramzan, N.
Iqbal, T.
Kazmi, M.
Ikhlaq, A.
Powiązania:
https://bibliotekanauki.pl/articles/779611.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
demineralization
leaching agent
physiochemical structure
alkali and alkaline earth metals
thermal degradation
Opis:
Energy generation from biomass presents some serious problems like slagging, fouling and corrosion of boilers. To address these problems, demineralization of biomass is performed using different leaching agents. This study is focused on determining the influence of leaching agents and leaching time on the physiochemical structure of rice husk during demineralization. Dilute (5% wt) solutions of HCl and H2SO4 were used for the demineralization of rice husk separately with leaching time of 15, 60 and 120 minutes. It is shown that H2SO4 exhibited higher removal of alkali and alkaline earth metals (AAEM) comparatively as depicted by the 34.2% decrease in ash content along with an increase of 7.10% in the heating value. The acid has been seen to induce more notable changes in physiochemical structure as depicted by the FTIR spectra and SEM micrographs. The thermal degradation behavior of the demineralized rice husk has also been reported.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 3; 117-121
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
TG-DTG-DSC, FTIR, DRIFT, and Py-GC-MS Studies of Thermal Decomposition for Poly(sodium acrylate)/Dextrin (PAANa/D) – New Binder BioCo3
Autorzy:
Grabowska, B.
Kaczmarska, K.
Bobrowski, A.
Żymankowska-Kumon, S.
Kurleto-Kozioł, Ż.
Powiązania:
https://bibliotekanauki.pl/articles/106999.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
polymer binders
foundry sands
thermal analysis
TG-DTG-DSC
FTIR
Py-GC-MS
thermal degradation
Opis:
TG-DTG-DSC, FTIR, DRIFT, and Py-GC-MS studies have been conducted to determine the effect of the thermal decomposition conditions and structure of foundry binder BioCo3 in the form of a composition poly(sodium acrylate)/dextrin (PAANa/D) on the progress of degradation in terms of processes occurring in foundry sands in contact with liquid metal. TG-DTG-DSC curves of the composition allowed us to determine the temperature range in which they do not undergo degradation, by which they do not lose their binding properties. With temperature increasing, physical and chemical changes occur that are related to the evaporation of solvent water (20–110°C), followed by the release of constitution water, and finally intermolecular dehydration (110–230°C). In this temperature range, processes that are mainly reversible take place. Within a temperature range of 450–826°C, polymer chains are decomposed, including the decomposition of side chains. Within a temperature range of 399–663°C, polymer composition decomposition can be observed (FTIR, DRIFT), and gas products are generated from this destruction (Py-GC-MS).
Źródło:
Journal of Casting & Materials Engineering; 2017, 1, 1; 27-32
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determinanty procesu degradacji termicznej aparatów wymiany ciepła w siłowniach parowych
The Heat Exchanger Thermal Degradation Process Determinants within the Steam Power Plants
Autorzy:
Hajduk, T.
Powiązania:
https://bibliotekanauki.pl/articles/342415.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Morski w Gdyni. Wydawnictwo Uniwersytetu Morskiego w Gdyni
Tematy:
siłownie parowe
wymienniki ciepła
degradacja cieplna
steam power plants
heat exchangers
thermal degradation
Opis:
Obecność zanieczyszczeń na powierzchniach wymiany ciepła aparatów wymiany ciepła w okrętowych i lądowych siłowniach parowych jest przyczyną m.in. wzrostu spiętrzeń temperatur oraz związanego z tym pogorszenia stopnia próżni w skraplaczach. W końcowym efekcie proces degradacji termicznej wymienników ciepła prowadzi do zmniejszenia sprawności danego układu cieplnego. Symptomy degradacji termicznej najczęściej definiowane są jako różnica między wartościami parametrów cieplno-przepływowych dla stanu referencyjnego i wartościami dla stanu aktualnego. W efekcie końcowym zjawisko degradacji cieplnej pociąga za sobą wzrost kosztów przetwarzania energii, a w konsekwencji prowadzi do zwiększonej degradacji środowiska naturalnego. W artykule opisano powyższe zjawiska oraz zaprezentowano determinanty degradacji termicznej wymienników ciepła siłowni parowych, opierając się na rezultatach własnych badań eksperymentalnych.
he deposits presence on the heat transfer surfaces of the heat exchangers within the stationary and the ship steam power plants cause an inscrease in terminal temperature difference values and entails a decrease of the vacuum level, as well. That fact leads to reducing the total efficiency of the thermal unit. Symptoms of heat degradation are usually defined as the difference between the values of thermal-flow parameters for the current and the reference state. Moreover, thermal degradation of any heat transfer device always entails an increase in the cost of energy conversion, leading to increasing the emission output of greenhouse gases and finally increasing the environmental degradation process. The above-mentioned phenomena, the determinants of the thermal degradation as well as the results of the author’s own experimental research have been presented in the paper.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Gdyni; 2017, 100; 87-99
1644-1818
2451-2486
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Gdyni
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Overall color parameter as a parameter determining the level of oxidation of olive oil
Autorzy:
Różańska, Anna
Namieśnik, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1179567.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
analytical chemistry
edible oils
food analysis
olive oil
overall color parameter
thermal degradation
Opis:
Edible fats are an important part of a human daily diet. They have a significant effect on the proper functioning of the human body. During frying, the oil is chemically modified and the fats consumed should have the highest oxidation stability. The subject of the study were samples of olive oil bought at local markets in Gdansk. Samples were heated at 20 °C, 60 °C, 100 °C, 140 °C and 180 °C. The aim of the study was to determine the differences in the level of oxidation of selected edible oils which were heated. Studies were performed using spectrophotometric techniques. The dependence between the level of oxidation of the olive oil samples and the value of the overall color parameter was determined. Based on the results obtained, the lower value of the color parameter overall, means that the oil is more degraded. The used procedure is characterized by an uncomplicated and low cost consuming stage of the preparation of the sample for analysis and also enables rapid analysis.
Źródło:
World Scientific News; 2017, 75; 81-88
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Abiotic Degradation on the Colorimetric Analysis, Mechanical Properties and Morphology of PLA Composites with Linen Fibers
Autorzy:
Tor-Świątek, Aneta
Garbacz, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/2024181.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
biocomposites
polyactide
flax fiber
thermal degradation
color
biokompozyty
poliaktyd
włókno lniane
degradacja termiczna
kolor
Opis:
The manufacturing of composites from biomaterials enables the production of environmentand user-friendly biodegradable products. The matrix of such composite materials is made of biopolymers such as PLA or PGA, while the reinforcement is usually made of natural fibers. Such composites have unique physical and mechanical properties as well as distinctive, eye-catching performance and aesthetic characteristics such as texture, color or roughness. This paper presents the results of colorimetric examination of polymer-linen biocomposite materials under abiotic degradation. The colorimetric examination was made based on a CIELAB model determining the values of lightness, color saturation, chromatic colors and total color difference. The SEM morphology of the specimen surface fracture was also examined. The obtained results show a significant effect of abiotic degradation on the tested parameters.
Źródło:
Advances in Science and Technology. Research Journal; 2021, 15, 1; 99-109
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toksyczność środowiska pożarowego w budynkach a bezpieczna i skuteczna ewakuacja ludzi
Toxicity of the fire environment in buildings and the safe and effective evacuation of people
Autorzy:
Jaskółowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/162296.pdf
Data publikacji:
2012
Wydawca:
Polski Związek Inżynierów i Techników Budownictwa
Tematy:
bezpieczeństwo pożarowe
środowisko pożarowe
toksyczność
rozkład termiczny
produkt rozkładu
fire safety
fire environment
toxicity
thermal degradation
degradation product
Opis:
W artykule omówiono wybrane problemy związane z oceną toksyczności środowiska pożarowego podczas pożarów w budynkach. Na podstawie analizy literatury przedmiotu (dokumentów prawnych, norm i innych źródeł) można stwierdzić, że problem oceny toksyczności środowiska pożarowego jest problemem ciągle nierozwiązanym. Ostatnie zmiany w klasyfikacji materiałów ze względu na reakcję na ogień nie uwzględniły toksyczności.
This article discusses selected problems relating to evaluation of the toxicity of a fire environment during fires in buildings. Based on analysis of the relevant literature (legal documents, standards and other sources) it can be concluded that the problem of evaluating the toxicity of the fire environment is one that remains unsolved. The most recent changes in the classification of materials based on reaction to fire did not take account of toxicity.
Źródło:
Przegląd Budowlany; 2012, R. 83, nr 1, 1; 40-45
0033-2038
Pojawia się w:
Przegląd Budowlany
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of gas chromatography to evaluate the quality of rapeseed oil
Autorzy:
Lubinska, Martyna
Namieśnik, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1179570.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
edible oils
mass spectrometry
quality markers
thermal degradation
two-dimensional gas chromatography
volatile organic compounds
Opis:
Two-dimensional gas chromatography is an analytical technique, which is increasingly being used in food research. Through the analysis of volatile fraction, it is possible to determine the quality of food products. One of the reasons for the deterioration of food is thermal degradation. Products that are often subject to degradation reactions due to temperatures are edible oils. In the thesis, the results of edible oils with different botanical origin are presented. The samples of oil were heated at temperatures of 20 °C, 60 °C, 100 °C, 140 °C and 180 °C. Based on the results of the chromatographic analysis, potential indicators of thermal degradation of edible oils were selected. The last step was to quantify the selected compounds to confirm that the typed chemical compounds are the markers of thermal decomposition of cooking oils. To calibrate, the method of standard additions was chosen
Źródło:
World Scientific News; 2017, 75; 96-105
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of the Thermal Degradation of the BioCo3 Polymer Binder
Badania degradacji termicznej spoiwa polimerowego BioCo3
Autorzy:
Grabowska, B.
Grabowski, G.
Olejnik, E.
Kaczmarska, K.
Powiązania:
https://bibliotekanauki.pl/articles/381155.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
polymer binder
foundry sand
thermal analysis
TG-DSC
thermal degradation
spoiwo polimerowe
masa formierska
analiza termiczna
degradacja termiczna
Opis:
The basic research included a thermal analysis of the BioCo3 polymer binder in the form of a water-based poly(sodium acrylate)/dextrin composition to determine the temperature range in which this binder does not degrade and hence does not lose its binding properties in the binder/matrix system. The thermal decomposition was proven to be complex and to occur in multiple stages. It was found that as the temperature rises, physical and chemical changes take place in the binder as a result of the solvent water (20-100°C) and then of the structural water evaporating, and finally of intermolecular dehydration reactions (100-220°C) Mainly reversible processes occur within this temperature range. Within the temperature range of 220-300°C, polymer chains decompose, which includes the disintegration of side groups and glycoside bonds. Between 300 and 500°C, the polymer composition decomposes producing with gaseous destruction products, including mainly small-molecule inorganic compounds (CO2, H2O, CO) and organic ones (hydrocarbons). The part of the mass which has not decomposed at the temperature of about 550°C may contain carbonised carbon.
Badania podstawowe obejmowały analizę termiczną spoiwa polimerowego BioCo3 w postaci wodnej kompozycji poli(akrylan sodu)/dekstryna, która umożliwiła ustalenie zakresu temperatury, w jakim nie ulega ono degradacji, przez co nie traci swoich właściwości wiążących w układzie spoiwo-osnowa. Wykazano, że przebieg termicznego rozkładu jest złożony i wieloetapowy. Stwierdzono, że wraz ze wzrostem temperatury w spoiwie dochodzi do zmian fizycznych i chemicznych związanych z odparowywaniem wody rozpuszczalnikowej (20-100°C), następnie wody konstytucyjnej i wreszcie z reakcjami dehydratacji intermolekularnej (100-220°C). W tym zakresie temperatury zachodzą głównie procesy odwracalne. W zakresie temperatury 220-300°C dochodzi do dekompozycji łańcuchów polimerowych, w tym rozpadu grup bocznych i wiązań glikozydowych. W zakresie temperatury 300-500°C następuje rozkład kompozycji polimerowej z powstawaniem gazowych produktów destrukcji, w tym przede wszystkim małocząsteczkowych związków nieorganicznych (CO2, H2O, CO) i organicznych (węglowodory). Część masy, która nie uległa rozkładowi w temperaturze około 550°C może zawierać skarbonizowany węgiel.
Źródło:
Archives of Foundry Engineering; 2013, 13, 1 spec.; 27-30
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The synergistic effect of boric acid and ammonium polyphosphate on the thermal degradation and flammability of pine-needles
Autorzy:
Li, L.
Hu, H.
Guo, C.
Powiązania:
https://bibliotekanauki.pl/articles/52633.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
synergistic effect
boric acid
ammonium polyphosphate
thermal degradation
flammability
pine needle
needle
pyrolysis
temperature
flame retardant
Opis:
The synergistic effect of ammonium polyphosphate (APP) and boric acid (BA) on the flame retardancy and thermal degradation of pine needles was investigated. Thermogravimetric analysis (TGA) showed that the presence of an ammoniumpolyphosphate and boric acid system increased the char residue and decreased the pyrolysis temperature of the pine needles. The derivative thermogravimetric analysis (DTG) showed that the ammonium polyphosphate and boric acid had shifted the degradation peaks of the pine needles to lower temperatures. The cone calorimetry test results showed that the values of HRR, THR, SPR, TSP and the mass loss (%) of the pine needles treated with ammonium polyphosphate and boric acid (APP/BA = 3/2)were significantly lower than the other samples. Therefore, the APP and BA system had a better effect on the pine needles overall than the APP alone.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 193
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
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