Thermo-oxidative decomposition behavior of starch-g-poly(citronellyl methacrylate) and starch-g-poly(citronellyl acrylate) copolymers

Prussian blue analogs (PBA) are widely studied for radioactive cesium decontamination. However, there are fewer works related to their post use storage. Considering the oxidative stabilization of the material after the selective uptake of Cs, the thermogravimetric properties in powder and bead form, with various Cs and other alkali metal ions adsorbed, and various heating rates were studied. TG-DTA taken in dry air condition shows an exothermic decomposition at ~270 °C. This temperature varied with the heating rate, mass, and the proportion of adsorbed ions. The best condition for complete oxidation of Prussian blue (PB) is found to be a gradual oxidative decomposition by heating in the temperature range of 200–220 °C until the total mass is decreased by >35%. After this, the temperature could be safely increased to >300 °C for the complete oxidative decomposition of PB that formed iron oxide and salt of the adsorbed Cs. A pilot scale test conducted using the radioactive Cs adsorbed Prussian blue microbeads (PB-b) confirmed that no Cs was released in the effluent air during the process.

Download Full-text

Thermo-oxidative Decomposition Behavior of Polyamide 6 Nanocomposites with Structurally Different Clays

Fire Retardancy Behavior of Polymer/Clay Nanocomposites - Springer Theses ◽

10.1007/978-981-10-8327-3_6 ◽

2018 ◽

pp. 111-138

Author(s):

Indraneel Suhas Zope

Keyword(s):

Polyamide 6 ◽

Oxidative Decomposition ◽

Decomposition Behavior

Download Full-text

Influence of thermal decomposition behavior of titanium precursors on (Ba,Sr)TiO3 thin films

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2001386 ◽

2001 ◽

Vol 11 (PR3) ◽

pp. Pr3-675-Pr3-682 ◽

Cited By ~ 2

Author(s):

Y. S. Min ◽

Y. J. Cho ◽

D. Kim ◽

J. H. Lee ◽

B. M. Kim ◽

...

Keyword(s):

Thin Films ◽

Thermal Decomposition ◽

Thermal Decomposition Behavior ◽

Decomposition Behavior

Download Full-text

Thermo-Oxidative Decomposition of Lovage (Levisticum officinale) and Davana (Artemisia pallens) Essential Oils under Simulated Tobacco Heating Product Conditions

Beiträge zur Tabakforschung International/Contributions to Tobacco Research ◽

10.2478/cttr-2020-0004 ◽

2020 ◽

Vol 29 (1) ◽

pp. 27-43

Author(s):

Emma Jakab ◽

Zoltán Sebestyén ◽

Bence Babinszki ◽

Eszter Barta-Rajnai ◽

Zsuzsanna Czégény ◽

...

Keyword(s):

Low Temperature ◽

Essential Oils ◽

Relative Yield ◽

Gas Chromatography Mass Spectrometry ◽

Intramolecular Rearrangement ◽

Oxidation Reactions ◽

Pyrolysis Gas ◽

Oxidative Decomposition ◽

Oxidative Pyrolysis ◽

Artemisia Pallens

SummaryThe thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]

Download Full-text

Electrochemical Vicinal Difluorination of Alkenes: Sustainable, Scalable, and Amenable to Electron-rich Substrates

10.26434/chemrxiv.9974687 ◽

2019 ◽

Author(s):

Sayad Doobary ◽

Alexi Sedikides ◽

Henry caldora ◽

Darren poole ◽

Alastair Lennox

Keyword(s):

Bioactive Compounds ◽

Hypervalent Iodine ◽

Electrochemical Generation ◽

Oxidative Decomposition ◽

Alkyl Groups ◽

Rich Functionality

Fluorinated alkyl groups are important motifs in bioactive compounds, positively influencing pharmacokinetics, potency and F conformation. The oxidative difluorination of alkenes represents an H important strategy for their preparation, yet current methods are limited in their alkene-types and tolerance of electron-rich, readily oxidized functionalities, as well as in their scalability. Herein, we report a method for the difluorination of a number of unactivated alkene-types that is tolerant of electron-rich functionality, giving products that are otherwise unattainable. Key to success is the electrochemical generation of a hypervalent iodine mediator (in the presence of nucleophilic fluoride and HFIP) using an ‘ex-cell’ approach, which avoids the oxidative decomposition of the substrate. The more sustainable conditions give good to excellent yields of product in up to decagram scales<br>

Download Full-text

A Kinetic Analysis of the Thermal-Oxidative Decomposition of Polypropylene

Journal of Fire Sciences ◽

10.1106/bq4t-j160-qma6-4yrm ◽

2000 ◽

Vol 18 (4) ◽

pp. 245-264 ◽

Cited By ~ 8

Author(s):

HYUN CHUL JUN ◽

HAE PYEONG LEE ◽

SUNG-CHUL YI ◽

KYONG OK YOO ◽

SEA CHEON OH

Keyword(s):

Kinetic Analysis ◽

Oxidative Decomposition ◽

Thermal Oxidative Decomposition

Download Full-text

Decomposition behavior in the early-stage oxidation of Sm2Co17-type magnets

Scripta Materialia ◽

10.1016/j.scriptamat.2021.113911 ◽

2021 ◽

Vol 200 ◽

pp. 113911

Author(s):

Yong Zhang ◽

Xun Cao ◽

Huiteng Tan ◽

Vincent Gill ◽

Alexis Lambourne ◽

...

Keyword(s):

Early Stage ◽

Decomposition Behavior

Download Full-text

A mechanism for fire retardancy realized by a combination of biofillers and ammonium polyphosphate in various polymer systems

Cellulose ◽

10.1007/s10570-021-03747-4 ◽

2021 ◽

Author(s):

Koki Matsumoto ◽

Tatsuya Tanaka ◽

Masahiro Sasada ◽

Noriyuki Sano ◽

Kenta Masuyama

Keyword(s):

Polymer Matrix ◽

Synergetic Effect ◽

Polymer System ◽

Ammonium Polyphosphate ◽

Fire Retardancy ◽

Polymer Systems ◽

Thermal Decomposition Behavior ◽

Burning Behavior ◽

The Matrix ◽

Decomposition Behavior

AbstractThis study focused on realizing fire retardancy for polymer composites by using a cellulosic biofiller and ammonium polyphosphate (APP). The motivation of this study was based on revealing the mechanism of the synergetic effect of a cellulosic biofiller and APP and determining the parameters required for achieving a V-0 rating in UL94 standard regardless of the kind of polymer system used. As for the polymer matrix, polypropylene and polylactic acid were used. The flammability, burning behavior and thermal decomposition behavior of the composites were investigated through a burning test according to the UL-94 standard, cone calorimetric test and thermogravimetric analysis. As a result, the incorporation of a high amount of cellulose enabled a V-0 rating to be achieved with only a small amount of APP despite the variation of the optimum cellulose loading between the matrix polymers. Through analysis, the results indicated that APP decreased the dehydration temperature of cellulose. Furthermore, APP promoted the generation of enough water as a nonflammable gas and formed enough char until the degradation of the polymer matrix was complete. The conditions required to achieve the V-0 rating were suggested against composites incorporating APP and biofillers. Furthermore, the suggested conditions were validated by using polyoxymethylene as a highly flammable polymer.

Download Full-text