scholarly journals Understanding thermal decomposition kinetics of flame-retardant thermoset polylactic acid

RSC Advances ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 3128-3139 ◽  
Author(s):  
Yihan Li ◽  
Zhe Qiang ◽  
Xie Chen ◽  
Jie Ren
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Polylactic Acid ◽  
Decomposition Kinetics ◽  
Ozawa Method ◽  
Local Activation ◽  
Local Activation Energy ◽  
Kinetics Of

The Flynn–Wall–Ozawa method was applied to study the local activation energy of flame retardant thermoset PLA, and the results showed that with an increase of conversion of thermal degradation, the local activation energy was increased slowly.

Application of Calculus Equation in Solving Thermal Decomposition Kinetics Parameters of Flame Retardant Wood

2014 ◽  
Vol 983 ◽  
pp. 190-193
Author(s):  
Cai Yun Sun ◽  
Yong Li Yang ◽  
Ming Gao
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Phosphoric Acid ◽  
Flame Retardant ◽  
Kinetic Parameters ◽  
Flame Retardancy ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Kinetics Parameters

Wood has been treated with amino resins and amino resins modified with phosphoric acid to impart flame retardancy. The thermal degradation of samples has been studied by thermogravimetry (TG) in air. From the resulting data, kinetic parameters for different stages of thermal degradation are obtained following the method of Broido. For the decomposition of wood and flame retardant wood, the activation energy is found to decrease from 122 to 72 kJmol-1.

Thermal Decomposition Kinetics of Flame Retardant Polybutylene Terephthalate Matrix Composites

2019 ◽  
Vol 956 ◽  
pp. 181-191
Author(s):  
Jian Lin Xu ◽  
Bing Xue Ma ◽  
Cheng Hu Kang ◽  
Cheng Cheng Xu ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Flame Retardant ◽  
Mass Loss Rate ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
Polybutylene Terephthalate ◽  
Kinetics Of

The thermal decomposition kinetics of polybutylene terephthalate (PBT) and flame-retardant PBT (FR-PBT) were investigated by thermogravimetric analysis at various heating rates. The kinetic parameters were determined by using Kissinger, Flynn-Wall-Ozawa and Friedman methods. The y (α) and z (α) master plots were used to identify the thermal decomposition model. The results show that the rate of residual carbon of FR-PBT is higher than that of PBT and the maximum mass loss rate of FR-PBT is lower than that of PBT. The values of activation energy of PBT (208.71 kJ/mol) and FR-PBT (244.78 kJ/mol) calculated by Kissinger method were higher than those of PBT (PBT: 195.54 kJ/mol) and FR-PBT (FR-PBT: 196.00 kJ/mol) calculated by Flynn-Wall-Ozawa method and those of PBT and FR-PBT (PBT: 199.10 kJ/mol, FR-PBT: 206.03 kJ/mol) calculated by Friedman methods. There is a common thing that the values of activation energy of FR-PBT are higher than that of PBT in different methods. The thermal decomposition reaction models of the PBT and FR-PBT can be described by Avarami-Erofeyev model (A1).

Thermal Decomposition Kinetics of RDX with Distributed Activation Energy Model

2013 ◽  
Vol 641-642 ◽  
pp. 144-147 ◽  
Author(s):  
Ming Hua Chen ◽  
Tao Zhang ◽  
Wen Ping Chang ◽  
Xiao Biao Jia
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Energy Model ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Distributed Activation Energy Model ◽  
Thermogravimetric Analyzer ◽  
Decomposition Stage ◽  
Decomposition Processes ◽  
Kinetics Of

The thermal decomposition kinetics of RDX at different rates was studied by thermogravimetric analyzer(TG) and the activation energy of RDX was calculated by distributed activation energy model. It is shown that the thermal decomposition processes of RDX were divided into three stages according to the TG curves, they are molten stage, thermal decomposition stage and eng stage. The activation energies of RDX are all between 124.34 and 181.48KJ•mol-1 in the thermal decomposition stage of non-monotonously increasing. The activation energy of RDX is 139.98 KJ•mol-1 in the molten stage, and the thermal decomposition stage is167.24KJ•mol-1.

Characteristics and thermal decomposition kinetics of wood-SiO2 composites derived by the sol-gel process

Holzforschung ◽  
2017 ◽  
Vol 71 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Ke-Chang Hung ◽  
Jyh-Horng Wu
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Apparent Activation Energy ◽  
Sol Gel ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Sol Gel Process ◽  
Kinetics Of

Abstract Wood-SiO2 composites (WSiO2Cs) were prepared by means of the sol-gel process with methyltrimethoxysilane (MTMOS) as a reagent, and the physical properties, structure and thermal decomposition kinetics of the composites has been evaluated. The dimensional stability of the WSiO2Cs was better than that of unmodified wood, especially in terms of the weight percent gain (WPG), which achieved values up to 30%. The 29Si-NMR spectra show two different siloxane peaks (T2 and T3), which supports the theory about the formation of MTMOS network structures. Thermal decomposition experiments were also carried out in a TG analyzer under a nitrogen atmosphere. The apparent activation energy was determined according to the iso-conversional methods of Friedman, Flynn-Wall-Ozawa, modified Coats-Redfern, and Starink. The apparent activation energy between 10 and 70% conversion is 147–172, 170–291, 189–251, and 192–248 kJ mol−1 for wood and WSiO2Cs with WPGs of 10, 20, and 30%, respectively. However, the reaction order between 10 and 70% conversion calculated by the Avrami theory was 0.50–0.56, 0.35–0.45, 0.33–0.44, and 0.28–0.48. These results indicate that the dimensional and thermal stability of the wood could be effectively enhanced by MTMOS treatment.

scholarly journals Modelling of Thermal Decomposition Kinetics of Proteins, Carbohydrates and Lipids Using Scenedesmus microalgae thermal Data

2020 ◽  
Vol 32 (11) ◽  
pp. 2921-2926
Author(s):  
BOTHWELL NYONI ◽  
PHUTI TSIPA ◽  
SIFUNDO DUMA ◽  
SHAKA SHABANGU ◽  
SHANGANYANE HLANGOTHI
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Bulk Material ◽  
Decomposition Kinetics ◽  
Second Order ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
High Heating ◽  
The Individual ◽  
Kinetics Of

In present work, the thermal decomposition behaviour and kinetics of proteins, carbohydrates and lipids is studied by use of models derived from mass-loss data obtained from thermogravimetric analysis of Scenedesmus microalgae. The experimental results together with known decomposition temperature range values obtained from various literature were used in a deconvolution technique to model the thermal decomposition of proteins, carbohydrates and lipids. The models fitted well (R2 > 0.99) and revealed that the proteins have the highest reactivity followed by lipids and carbohydrates. Generally, the decomposition kinetics fitted well with the Coats-Redfern first and second order kinetics as evidenced by the high coefficients of determination (R2 > 0.9). For the experimental conditions used in this work (i.e. high heating rates), the thermal decomposition of protein follows second order kinetics with an activation energy in the range of 225.3-255.6 kJ/mol. The thermal decomposition of carbohydrate also follows second order kinetics with an activation energy in the range of 87.2-101.1 kJ/mol. The thermal decomposition of lipid follows first order kinetics with an activation energy in the range of 45-64.8 kJ/ mol. This work shows that the thermal decomposition kinetics of proteins, carbohydrates and lipids can be performed without the need of experimentally isolating the individual components from the bulk material. Furthermore, it was shown that at high heating rates, the decomposition temperatures of the individual components overlap resulting in some interactions that have a synergistic effect on the thermal reactivity of carbohydrates and lipids.

Decomposition Kinetics of Switchgrass: Estimating Activation Energy

2014 ◽  
Vol 881-883 ◽  
pp. 726-733
Author(s):  
Gui Ying Xu ◽  
Jiang Bo Wang ◽  
Ling Ping Guo ◽  
Guo Gang Sun
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Apparent Activation Energy ◽  
High Purity ◽  
Isoconversional Methods ◽  
Decomposition Kinetics ◽  
Heating Rates ◽  
Model Free ◽  
Chemical Utilization ◽  
Kinetics Of

TG analysis was used to investigate the thermal decomposition of switchgrass, which is a potential gasification feedstock. 10 mg switchgrass sample with the particles between 0.45 and 0.70 mm was linearly heated to 873 K at heating rates of 10, 20, 30 K/min, respectively, under high-purity nitrogen. The Kissinger method and three isoconversional methods including Friedman, Flynn-wall-Ozawa, Vyazovkin and Lenikeocink methods were used to estimate the apparent activation energy of switchgrass. With the three isoconversional methods, it can be concluded that the activation energy increases with increasing conversion. The four model free methods reveal activation energies in the range of 70-460 kJ/mol. These activation energy values provide the basic data for the thermo-chemical utilization of the switchgrass.

Crystallization Kinetics of the Cu47.5Zr47.5Al5 Bulk Metallic Glass under Continuous and Iso-Thermal Heating

2011 ◽  
Vol 99-100 ◽  
pp. 1052-1058 ◽  
Author(s):  
Chun Xia Hu ◽  
Gai Lian Li ◽  
Yang Shi
Keyword(s):  
Activation Energy ◽  
Crystallization Kinetics ◽  
The Body ◽  
Avrami Exponent ◽  
Isothermal Kinetics ◽  
Continuous Heating ◽  
Local Activation ◽  
Body Center Cubic ◽  
Local Activation Energy ◽  
Kinetics Of

The crystallization kinetics of Cu47.5Zr47.5Al5 BMG was studied by differential scanning calorimetry (DSC) using the mode of continuous heating and isothermal annealing. It is found that Tg, Tx, and Tp, display a dependence on the heating rate in the case of continuous heating. The activation energies, Eg, Ex and Tp determined by the Kissinger method, yield 445, 264 and 285 kJ/mol, respectively. The local activation energy, E(x), was determined by the Doyle-Ozawa method, which gives the average activation energy 204 kJ/mol. On the other hand, the isothermal kinetics was modeled by the Johnson-Mehl-Avrami (JMA) equation, the Avrami exponent versus crystallization fraction was calculated at different temperatures. Details of nucleation and growth behaviors are discussed in terms of the local Avrami exponent and local activation energy during the isothermal crystallization. X-ray shows that the quenched BMG only includes the glass single phase. The BMG heated to 873 K has the precipitation of the body-center cubic (BCC) CuZr.

Study on Thermal Decomposition Kinetics of Nano-Cr(OH)3 Powder

2014 ◽  
Vol 692 ◽  
pp. 377-380 ◽  
Author(s):  
Feng Pan ◽  
Zai Yuan Li ◽  
Chun Ji Li
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Shape Factor ◽  
Decomposition Analysis ◽  
Decomposition Kinetics ◽  
Peak Shape ◽  
Exponential Factor ◽  
Mechanism Function ◽  
Kinetics Of ◽  
Tga Analysis

Abstract. This paper studies on the thermal decomposition analysis kinetics of nanometer powders. The DTA-TG-DTG curves obtain by SDT 2960 Simultaneous DSC-TGA analysis apparatus. Under the condition of N2atmosphere operation and rise temperature velocity was 10°C·min-1. The mechanism function dα/dt=κ(1-α)nis used to calculate the kinetics factors. Reaction progressionnwas obtained by calculation of the kissinger peak shape factor method. The results showed that the apparent activation energy of nano-Ni(OH)2was 254.027 KJ·mol-1, the pre-exponential factor was 3.062×1036, the reaction progression was obtained as 1.560, the kinetic equation is dα/dt=3.062×1036exp(-30554.166/T)(1-α)1.560

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