Thermal Degradation of Aged Chloroprene Rubber Studied by Thermogravimetric Analysis

2001 ◽  
Vol 74 (4) ◽  
pp. 622-629 ◽  
Author(s):  
Elton L. G. Denardin ◽  
Dimitrios Samios ◽  
Paulo R. Janissek ◽  
Gabriel P. de Souza
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Mass Loss ◽  
Activation Energies ◽  
Half Width ◽  
Temperature Elevation ◽  
Kinetic Methods ◽  
Degradation Processes ◽  
Chloroprene Rubber ◽  
Differential Thermogravimetric Analysis

Abstract The thermal degradation of original and aged chloroprene rubber was studied using thermogravimetric analysis. Thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTG) techniques were used to detect the mass loss during the temperature elevation. By the analysis of the mass loss curves through usual kinetic methods, it was possible to evaluate the different degradation processes present in the overall degradation. The activation energies of the degradation processes were obtained using the dynamic, non-isothermal Kissinger and Osawa methods and the half-width at half-high technique (HWHH). The results obtained demonstrate clearly the differences between original and aged chloroprene rubber as well as the influence of the air and N2 in TGA.

scholarly journals Thermal Behavior of Sweet Potato Starch by Non-Isothermal Thermogravimetric Analysis

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 699 ◽  
Author(s):  
Ying Liu ◽  
Liutao Yang ◽  
Chunping Ma ◽  
Yingzhe Zhang
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Sweet Potato ◽  
Degradation Kinetics ◽  
Potato Starch ◽  
Activation Energies ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Sweet Potato Starch

In this study, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) methods were used to study the structure, the thermal degradation kinetics, and the thermogram of sweet potato starch, respectively. The thermal decomposition kinetics of sweet potato starch was examined within different heating rates in a nitrogen atmosphere. Different models of kinetic analysis were used to calculate the activation energies using the thermogravimetric data of the thermal degradation process. The activation energies got from Kissinger, Flynn–Wall–Ozawa, and Šatava–Šesták models were 173.85, 174.87, and 174.34 kJ·mol−1, respectively. Thermogravimetry–Fourier transform infrared spectroscopy (TG-FTIR) analysis showed that the main pyrolysis products included water, carbon dioxide, and methane.

Thermal properties and thermal degradation kinetics of phenolic and wood flour-reinforced phenolic foams

2016 ◽  
Vol 51 (1) ◽  
pp. 125-138 ◽  
Author(s):  
JC Domínguez ◽  
B del Saz-Orozco ◽  
M Oliet ◽  
MV Alonso ◽  
F Rodriguez
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Wood Flour ◽  
Activation Energies ◽  
Thermal Degradation Kinetics ◽  
Kinetic Methods ◽  
Model Free ◽  
Phenolic Foam ◽  
Kinetics Of

In the present work, the thermal stability, changes in chemical structure during thermal degradation, and the kinetics of thermal degradation of a phenolic foam were studied. An 8.5 wt% of Pinus radiata wood flour reinforcement was added to the phenolic foam. A commercial phenolic resol was used as the matrix for the foam. The wood flour-reinforced foam showed a structure similar to the phenolic foam according to the Fourier transform infrared spectroscopy results. The wood flour increased the thermal stability of the phenolic foam in the first stage of thermal degradation ( T 5%), decreased it in the second step ( T 25%), and negligibly influenced the final stage. The activation energies of the degradation processes of the studied materials were obtained by the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa model-free kinetic methods and a 2-Gaussian distributed activation energy model. The values of the activation energies obtained by the model-free kinetic methods for the first degradation stage of the phenolic foams were in a range between 110 and 170 kJ mol−1, whereas for the wood flour it was 162 kJ mol−1 for almost all of the conversion range of its main degradation stage. The applied models showed good fits for all the materials, and the activation energies calculated were in agreement with the values found in the literature.

The Effect of Glycidyl Silane as Coupling Agent in Intumescent Flame Retardant System

2013 ◽  
Vol 664 ◽  
pp. 677-682
Author(s):  
Hambali Raden Siti Amirah ◽  
Ahmad Faiza Mohd ◽  
Mohd Firdaus Yhaya ◽  
Rahmah Mohamed ◽  
Mohamed Nur Raihan
Keyword(s):  
Fourier Transform ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Ethylene Glycol ◽  
Burning Rate ◽  
Chemical Bonding ◽  
Coupling Agent ◽  
The Other ◽  
Silane Treatment ◽  
Char Formation

The effect of different carbonizing agents; ethylene glycol, glycerol, and pentaerythritol to the char formation were studied in this research. After burning process, formulation with ethylene glycol, glycerol, and pentaerythritol showed chars thickness of 10 mm, 32 mm, and 45 mm. The chars’ strength at peak force was recorded at 3.20 N, 7.75 N, and 9.48 N while the burning rate of each sample were 5.23 x 10-4 mm/s, 4.20 x10-4 mm/s, and 6.24 x10-4 mm/s respectively. Formulation with glycerol as carbonizing agent showed the lowest burning rate as compared to the other formulations. Additional formulation with glycidyl silane as coupling agent in glycerol formulation was also studied. The formation of chemical bonding between silane, glycerol, and epoxy glycerol was confirmed by Fourier Transform Infrared (FTIR) absorption peak at 767.25 cm-1. The burning rate was 1.44 x 10-5 mm/s after silane treatment. Thermal degradation of the silane-treated resin started at 220°C as measured by thermogravimetric analysis (TGA).

INVESTIGATION OF THERMAL DEGRADATION OF POULTRY PROCESSING DEWATERED SLUDGE USING THERMOGRAVIMETRIC ANALYSIS METHOD

2015 ◽  
Vol 76 (5) ◽  
Author(s):  
N. Aniza ◽  
S. Hassan ◽  
M. F. M. Nor ◽  
K. E. Kee ◽  
Aklilu T.
Keyword(s):  
Particle Size ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Heating Rate ◽  
Degradation Process ◽  
Heating Rates ◽  
Initial Stage ◽  
Poultry Processing ◽  
Effect Of Particle Size ◽  
Dewatered Sludge

Thermal degradation of Poultry Processing Dewatered Sludge (PPDS) was studied using thermogravimetric analysis (TGA) method. The effect of particle size on PPDS samples and operational condition such as heating rates were investigated. The non-isothermal TGA was run under a constant flow of oxygen at a rate of 30 mL/min with temperature ranging from 30ºC to 800ºC. Four sample particle sizes ranging between 0.425 mm to 2 mm, and heating rate between 5 K/min to 20 K/min were used in this study. The TGA results showed that particle size does not have any significant effect on the thermogravimetry (TG) curves at the initial stage, but the TG curves started to separate explicitly at the second stage. Particle size may affect the reactivity of sample and combustion performance due to the heat transfer and temperature gradient. The TG and peak of derivative thermogravimetry (DTG) curves tend to alter at high temperature when heating rate is increased most likely due to the limitation of mass transfer and the delay of degradation process. 

Thermooxidative Aging Studies on Silicone Rubber and Lifetime Prediction

2013 ◽  
Vol 777 ◽  
pp. 11-14
Author(s):  
You Shan Wang ◽  
Sha Sha Jiang ◽  
Yu Peng Liu
Keyword(s):  
Silicone Rubber ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Activation Energies ◽  
Lifetime Prediction ◽  
Arrhenius Behavior ◽  
Compression Set ◽  
Degradation Processes ◽  
Aging Studies ◽  
Significant Compression

Silicone rubber have been aged in air while under 25% compression at temperature up to 250°C. These studies examined the compression set of silicone rubber at accelerated (elevated) temperatures and were then used to make predictions about compression set at room temperature. The data obtained could be amenable to timetemperature superposition and Arrhenius treatment. The results suggest the presence of two degradation processes with activation energies of 71.6 kJ mol-1 (for temperatures above 165 °C) and 26.08 kJ mol-1 (for temperatures below 165 °C). Based on the extrapolation of the non-Arrhenius behavior, it was estimated that significant compression set loss would occur after around 67 years at 25 °C.

scholarly journals Synthesis and Electrochemical Properties of C/LiMnPO4 Cathode Materials by Complex Polymerized Method

2011 ◽  
Vol 485 ◽  
pp. 115-118
Author(s):  
Atsushi Fujita ◽  
Fuminari Isobe ◽  
Takayuki Kodera ◽  
Takashi Ogihara
Keyword(s):  
Thermogravimetric Analysis ◽  
Electrochemical Properties ◽  
Carbon Content ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
Type Structure ◽  
Initial Discharge Capacity ◽  
Initial Discharge ◽  
Differential Thermogravimetric Analysis

C/LiMnPO4 materials were synthesized by the complex polymerized method. An orthorhombic olivine type structure was obtained by calcination at temperatures over 973 K under an argon/hydrogen (5%) atmosphere. Differential thermogravimetric analysis showed that the carbon content of C/LiMnPO4 was about 65 wt%. The initial discharge capacity of C/LiMnPO4 calcined at 973 K was 135 mAh/g at 0.1 C and 60 mAh/g at 1 C.

Non-isothermal degradation kinetics for polycarbonate/ polymethylphenylsilsesquioxane composites

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiangbo Wang ◽  
Zhong Xin
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Flame Retardancy ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Nitrogen Atmosphere ◽  
Ozawa Method ◽  
Degradation Behaviors ◽  
Thermal Degradation Process

AbstractThe thermal degradation behaviors of PC/PMPSQ (polymethylphenylsilsesquioxane) systems were investigated by thermogravimetric analysis (TGA) under non-isothermal conditions in nitrogen atmosphere. During non-isothermal degradation, Kissinger and Flynn-Wall-Ozawa methods were used to analyze the thermal degradation process. The results showed that a remarkable decrease in activation energy ( E ) was observed in the early and middle stages of thermal degradation in the presence of PMPSQ, which indicated that the addition of PMPSQ promoted the thermal degradation of PC. Flynn-Wall-Ozawa method further revealed that PMPSQ significantly increased the activation energy of PC thermal degradation in the final stage, which illustrated that the PMPSQ stabilized the char residues and improved the flame retardancy of PC in the final period of thermal degradation process

Characterization and thermal degradation kinetics of thermoplastic polyimide based on BAPP

2017 ◽  
Vol 30 (7) ◽  
pp. 787-793 ◽  
Author(s):  
Xu Su ◽  
Yong Xu ◽  
Linshuang Li ◽  
Chaoran Song
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Step Method ◽  
Nitrogen Derivative ◽  
Degradation Reaction ◽  
Kinetics Of

Two kinds of thermoplastic polyimides (PIs) were synthesized via a two-step method with 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4′-oxydianiline (ODA) diamine, and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and their thermal degradation kinetics was studied by thermogravimetric analysis at different heating rates under nitrogen. Derivative thermogravimetric analysis curves indicated a simple, single-stage degradation process in PI BTDA-BAPP and a two-stage degradation process in PI BTDA-ODA-BAPP. The activation energies ( Eas) of the thermal degradation reaction were determined by the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods without a knowledge of the kinetic reaction mechanism. By comparing the values of Ea and weight loss temperatures, it was demonstrated that the thermal stability of PI BTDA-ODA-BAPP was superior to that of PI BTDA-BAPP.

scholarly journals Analysis on the MSW thermal degradation processes

2013 ◽  
Vol 9 (1) ◽  
pp. 57-62
Keyword(s):  
Thermal Degradation ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Degradation Kinetics ◽  
Variable Temperature ◽  
Fixed Bed ◽  
Reduction Rate ◽  
Pollutant Emissions ◽  
Process Conditions ◽  
Degradation Processes

The waste to renewable energy source has become a priority in the wastes treatment field. The research goal is not only the wastes destruction but also a better thermal energy recovery from the processes. The municipal solid waste presents a high heterogeneity degree from the dimensional point of view, form and its components specific weight of as well as thermal-chemical characteristics. That’s why there are many treatment methods, each one with its own particularities. For a better understanding of the phenomenon during thermal degradation processes both under pyrolysis or atmospheric pressure gasification stages we first accomplished a laboratory scale series of experiments in a tubular reactor, on small quantities (5 – 10 grams) of reconstituted urban wastes. For the validation of the obtained data on more representative samples we extended the experiment to an original industrial scale pilot installation that enables the continuous thermal treatment of 10 – 50 waste kilograms per hour under oxidant or non-oxidant atmosphere (on choice) and at variable temperature between 400 °C – 1100 ºC. The residential time of the treated sample in the installation and the flow conditions can be set independently. The installation reproduces the incinerators or the pyrolysis / gasification reactor process conditions and provides complete information on the wastes thermal degradation kinetics and on the pollutant emissions. The particularity of the device consists in the product advancing piston – like flow system based on the bed vibration. The product particles in the bed have a translation movement without any layer shift. Therefore the particles distribution in a given product bed section is the same all along the installation from the feeding inlet to the extraction. That characteristic enables us to extrapolate and compare the laboratory results of the fixed bed treatment to the industrial pilot continuously treatment applied on the same product: reconstituted municipal solid waste, one of the most heterogynous solid wastes in mixture. The main targets were the sample mass reduction rate, the resulting gases composition, the samples mechanical behavior for different temperature levels, residential time, treatment atmosphere conditions and different steam flow rates (in the gasification process). The results were compared to an established reference – the incineration. The paper presents the research and results on the degradation mechanisms of MSW treated samples in those two equipments from the Science Division CNRS, Department of Industrial Methods, University of Technology Compiègne, France.

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