Note: Differential thermal analysis and limiting oxygen index of papyrus and its treatment with fire retardants

Cellulose treated with flame retardant was studied by thermogravimetry (TG), differential thermal analysis (DTA), limiting oxygen index (LOI) and IR. The kinetic parameters for the thermal degradation are obtained following the method of Broido. For the flame retardant cellulose, the activation energy and decomposition temperature were much decreased while char yield and LOI were increased. The main thermal decomposition of the samples with higher LOI occurs at lower temperatures, while that with lower LOI occurs at higher temperatures.

Download Full-text

Thermal and fire properties of medium-density fiberboard prepared with huntite/hydromagnesite and zinc borate

BioResources ◽

10.15376/biores.15.3.5940-5950 ◽

2020 ◽

Vol 15 (3) ◽

pp. 5940-5950

Author(s):

Derya Ustaömer ◽

Umut Emre Başer

Keyword(s):

Thermal Conductivity ◽

Oxygen Index ◽

Medium Density Fiberboard ◽

Control Sample ◽

Zinc Borate ◽

Medium Density ◽

Fire Retardants ◽

Limiting Oxygen Index ◽

Fire Properties ◽

Residual Weight

Effects of mineral-based fire retardants were investigated relative to the thermal and fire properties of medium-density fiberboard (MDF) via thermogravimetric analysis (TGA), limiting oxygen index (LOI), and thermal conductivity testing. Mineral-based chemicals containing huntite /hydromagnesite and zinc borate (ZB) were used at different concentrations. Changes in all values were observed depending on the type and concentration of chemicals. According to TGA evaluation, the residual weights in the MDF samples manufactured with mineral-based chemicals were higher than the residual weight in the control MDF sample. Limiting oxygen index testing results showed higher values for the MDF samples manufactured with mineral-based chemicals than for the control sample. The LOI values increased with the increment of chemical concentration, and the highest value was observed in group B12. The thermal conductivity trends of the MDF samples varied depending on the type and concentration of chemicals. Generally, the thermal conductivity values of the MDF samples manufactured with chemicals were found to be higher than the value of the control. These results suggested that these chemicals with various combinations should be evaluated as fire retardants for wood and wood-based panel industry.

Download Full-text

A dynamical systems model of the limiting oxygen index test

The ANZIAM Journal ◽

10.1017/s1446181100011457 ◽

2001 ◽

Vol 43 (1) ◽

pp. 105-117 ◽

Cited By ~ 13

Author(s):

M. I. Nelson ◽

H. S. Sidhu ◽

R. O. Weber ◽

G. N. Mercer

Keyword(s):

Dynamical Systems ◽

Bifurcation Point ◽

Mode Of Action ◽

Oxygen Index ◽

Polymeric Materials ◽

Index Test ◽

Fire Retardants ◽

Limiting Oxygen Index ◽

Systems Model ◽

Systems Framework

AbstractOxygen index methods have been widely used to measure the flammability of polymeric materials and to investigate the effectiveness of fire-retardants. Using a dynamical systems framework we show how a limiting oxygen index can be identified with an appropriate bifurcation.The effectiveness of fire-retardants in changing the limiting oxygen index is calculated by unfolding the bifurcation point with a suitable non-dimensionalised variable, which depends upon the mode of action of the additive. In order to use this procedure it is essential the model is non-dimensionalised so as to retain the variables of interest as distinct continuation parameters.

Download Full-text

Thermal Stability of Cotton Cellulose Modified with Flame Retardants

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.152-153.504 ◽

2010 ◽

Vol 152-153 ◽

pp. 504-507

Author(s):

Gui Fen Li

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Thermal Analysis ◽

Flame Retardants ◽

Oxygen Index ◽

Cotton Cellulose ◽

Char Yield ◽

Untreated Sample ◽

Limiting Oxygen Index ◽

Thermal Stability Of

The thermal stability of cotton cellulose treated with chemical mixtures containing P and N was studied by thermal analysis, infrared spectroscopy, char yield and limiting-oxygen-index (LOI). Our experiments demonstrated that the temperature and activation energy of pyrolysis were lower and the values of Char yield and LOI were greater for cotton cellulose treated with flame retardant than those for untreated sample.

Download Full-text

Fire Retardant Cellulose Characterized by Thermal Degradation Behavior

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.197-198.631 ◽

2011 ◽

Vol 197-198 ◽

pp. 631-634

Author(s):

Ming Gao ◽

Yu Qing Yan

Keyword(s):

Activation Energy ◽

Thermal Analysis ◽

Thermal Decomposition ◽

Thermal Degradation ◽

Oxygen Index ◽

Fire Retardant ◽

Decomposition Temperature ◽

Degradation Behavior ◽

Limiting Oxygen Index ◽

Thermal Degradation Behavior

Cellulose treated with fire retardant was studied by thermogravimetry (TG), differential thermal analysis (DTA) and limiting oxygen index (LOI). The kinetic parameters for the thermal degradation are obtained following the method of Broido. For the fire retardant cellulose, the activation energy and decomposition temperature were much decreased while char yield and LOI were increased. The main thermal decomposition of the samples with higher LOI occurs at lower temperatures, while that with lower LOI occurs at higher temperatures.

Download Full-text

Zeolites Fit For A Crown: Probing Host-Guest Interactions with Thermogravimetric Methods

10.26434/chemrxiv.7429961 ◽

2018 ◽

Author(s):

Asel Sartbaeva ◽

Paul R. Raithby ◽

Remi Castaing ◽

Antony Nearchou

Keyword(s):

Mass Spectrometry ◽

Thermal Analysis ◽

Differential Thermal Analysis ◽

Petrochemical Industry ◽

Rational Use ◽

New Methodologies ◽

First Time ◽

Kinetics Of

Through a combination of thermogravimetry, mass spectrometry and differential thermal analysis, we demonstrate for the first time that all four zeolites show experimental differences in their host-guest interactions with 18C6. In addition, we have estimated the kinetics of 18C6 decomposition, which is a technique that has not been applied to zeolites previously. Using these findings as a toolkit, a more rational use of OSDAs can be utilised to prepare designer zeolites. Furthermore, the new methodologies presented herein can be applied to current zeolites, such as MFI-type zeolites used in the petrochemical industry.

Download Full-text

PHASE EQUILIBRIUM IN THE AS2TE3-TM2TE3 SYSTEM.

EurasianUnionScientists ◽

10.31618/esu.2413-9335.2020.5.77.985 ◽

2020 ◽

Vol 5 (8(77)) ◽

pp. 65-68

Author(s):

Teymur Mammad Ilyasly ◽

Rahman Hasanaga Fatullazade ◽

Zakir Islam Ismailov ◽

Nigar Nadir Jafarova

Keyword(s):

Thermal Analysis ◽

Solid Solution ◽

Differential Thermal Analysis ◽

Phase Equilibrium ◽

Physicochemical Properties ◽

Thermal Effects ◽

Isothermal Annealing ◽

Intermediate Phase ◽

Physicochemical Analysis ◽

Two Phases

The synthesis of alloys of the system was carried out stepwise in rotary furnaces. The synthesis mode was selected based on the physicochemical properties of the elementary components. For homogenization, the alloys were subjected to isothermal annealing at 750 and 1275 K, depending on the Tm2Te3 concentration, for 250 h after homogenization of the alloys, they were subjected to physicochemical analysis. The results of differential thermal analysis showed that reversible thermal effects are observed in the alloys of the system. In alloys in a 1: 1 ratio, a new intermediate phase is formed with a composition corresponding to the TmAsTe3 compound. The homogeneity area is observed in the concentration range 52.5-47.5. It was found that in the concentration range 98.5-52.5 Tm2Te3 there are two phases - a mixture of β and of the solid solution, and in the concentration range of 47.51 mol% Tm2Te3 phases and α are in equilibrium. ) 66 The eutectic has coordinates of 11.5 mol Tm2Te3 at a temperature of 575 K.

Download Full-text

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

SCIENTIA : Jurnal Farmasi dan Kesehatan ◽

10.36434/scientia.v5i1.61 ◽

2016 ◽

Vol 5 (1) ◽

pp. 6

Author(s):

Budi Setiawan ◽

Erizal Zaini ◽

Salman Umar

Keyword(s):

Electron Microscopy ◽

Thermal Analysis ◽

Scanning Electron Microscopy ◽

Fourier Transform ◽

Differential Thermal Analysis ◽

Fourier Transform Infrared ◽

X Ray Diffraction ◽

Poloxamer 188 ◽

X Ray ◽

Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik menggunakan analisis varian satu arah SPSS 17.

Download Full-text

Kinetics of temperature-programmed reactivation of a hydrodesulphurization catalyst

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19833340 ◽

1983 ◽

Vol 48 (12) ◽

pp. 3340-3355 ◽

Cited By ~ 2

Author(s):

Pavel Fott ◽

Pavel Šebesta

Keyword(s):

Carbon Dioxide ◽

Thermal Analysis ◽

Differential Thermal Analysis ◽

Thin Layer ◽

Kinetic Parameters ◽

Diffusion Region ◽

Reaction Heat ◽

Gaseous Products ◽

Temperature Programmed ◽

Kinetics Of

The kinetic parameters of reactivation of a carbonized hydrodesulphurization (HDS) catalyst by air were evaluated from combined thermogravimetric (TG) and differential thermal analysis (DTA) data. In addition, the gaseous products leaving a temperature-programmed reactor with a thin layer of catalyst were analyzed chromatographically. Two exothermic processes were found to take part in the reactivation, and their kinetics were described by 1st order equations. In the first process (180-400 °C), sulphur in Co and Mo sulphides is oxidized to sulphur dioxide; in the second process (300-540 °C), in which the essential portion of heat is produced, the deposited carbon is oxidized to give predominantly carbon dioxide. If the reaction heat is not removed efficiently enough, ignition of the catalyst takes place, which is associated with a transition to the diffusion region. The application of the obtained kinetic parameters to modelling a temperature-programmed reactivation is illustrated on the case of a single particle.

Download Full-text

Effect of experimental conditions on the differential thermal-analysis of karnallite type hydrates

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19842770 ◽

1984 ◽

Vol 49 (12) ◽

pp. 2770-2775

Author(s):

Vladimir Z. Poilov ◽

Jana Ederová ◽

Antonín Blažek

Keyword(s):

Thermal Analysis ◽

Differential Thermal Analysis ◽

Experimental Conditions

Article in Russian

Download Full-text