• Title, Summary, Keyword: Kissinger method

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Evaluation of the Activation Energy of Chlorinated Poly Vinyl Chloride (CPVC) Using Thermogravimetric Analysis (TGA를 이용한 Chlorinated Poly Vinyl Chloride(CPVC)의 활성화 에너지 평가)

  • Park, Hyung-Ju
    • Fire Science and Engineering
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    • v.33 no.1
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    • pp.1-6
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    • 2019
  • The activation energy of CPVC (Chlorinated Poly Vinyl Chloride) used for non-metallic synthetic resin piping in fire-fighting was measured by thermogravimetric analysis (TGA). The activation energy was determined using by TGA kinetic methods, such as Kissinger and Flynn-Wall-Ozawa method. The calculated activation energy was 128.07 kJ/mol (Kissinger method) and 145.60 kJ/mol (Flynn-Wall-Ozawa method). The difference in activation energies calculated by the Kissinger method and Flynn-Wall-Ozawa method was not considered to be significant considering that the different analysis methods. The combustion characteristics will be tested in a future study through an evaluation of thermal deterioration using an accelerated deterioration and air oven aging test and the lifetime of CPVC will be predicted.

Characterization on Co-Combustion of Coal and Paper Mill Sludge (석탄과 제지슬러지 혼소에 따른 연소특성에 관한 연구)

  • Lee, Kamp-Du;Ryu, Tae-Uk;Park, Sang-Won
    • Journal of Environmental Science International
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    • v.22 no.3
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    • pp.331-339
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    • 2013
  • Efforts were made to determine the activation energy and the reaction order by adopting Kissinger and Flynn-Wall-Ozawa analysis methods. All the data were acquired from TGA thermograms for the mixed fuels with different temperature heating rates. It could be known that both the coal and the mixed fuels decomposed thermally at temperature ranges of $300{\sim}700^{\circ}C$. The temperature at the maximum reaction rate, Tp, could be determined by DTG method, which could be obtained by differentiation of TGA thermogram. Kissinger analysis showed the linear relationship with experimental data, showing the activation energy of $319.64{\pm}4$ kJ/mol. From Flynn-Wall-Ozawa analysis, it was shown that the activation energies and the reaction orders did not undergo any significant changes with both the conversions and the heating rates. It was considered from this facts that the combustion mechanism of the mixed fuels could not be affected by the extent of conversion and heating rate. In the present study, the activation energies showed different values according to the different analysis methods. The difference might be originated from the inconsistency of the mathematical data treatment method. In other words, while the activation energies obtained from the Kissinger method indicated the average values for overall reaction, that from Flynn-Wall-Ozawa method showed the average values for the each conversion around Tp.

Characteristics of Medical Polymer Based on Epoxy Resin System -Cure Characteristics for DGEBA/MDA/PGE- DMU System by Kissinger and Ozawa Equations- (에폭시 수지계 의료용 고분자 재료의 특성 연구 - Kissinger 식과 Ozawa 식에 의한 DGEBA/MDA/PGE-DMU 계의 경화특성 -)

  • Kim, Jang-Hoon;Lee, Jae-Young;Kim, Sang-Wook;Sim, Mi-Ja
    • Korean Journal of Materials Research
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    • v.11 no.9
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    • pp.727-732
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    • 2001
  • The cure kinetics of diglycidyl ether of bisphenol A (DGEBA)/4,4'- methylene dianiline (MDA) system with synthesized phenyl glycidyl ether-dimethylurea (PGE-DMU) was studied by Kissinger and Ozawa equations with DSC analysis in the temperature range of $20~300^{\circ}C$ To investigate the reaction mechanism between epoxy group of PGE and urea group of DMU, FT-lR spectroscopy analysis was used. The epoxide group of PGE reacted with the urea group of DMU and formed a hydroxyl group which acted as a catalyst on the cure reaction of other epoxide and amine groups. The activation energy of DGEBA/MDA system without PGE-DMU was 46.5 kJ/mol and those of the system with 5 and 10 phr of PGE- DMU were 43.4 and 37.0 kJ/mol, respectively. Ozawa method also showed the same tendency.

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Cure Kinetics of DGEBA/MBA/MN and DGEBA/MDA/MN/HQ Systems by Kissinger Equation and Fractional Life Method (Kissinger Equation과 Fractional Life법에 의한 DGEBA/MDA/MN계와 DGEBA/MDA/MN/HQ계의 경화반응 속도론)

  • Lee, Jae-Young;Shim, Mi-Ja;Kim, Sang-Wook
    • Applied Chemistry for Engineering
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    • v.5 no.4
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    • pp.731-736
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    • 1994
  • Cure kinetics of DGEBA/MDA/MN system with and without HQ were studied by Fractional life method and Kissinger equation. And the effect of HQ as a catalyst was studied. As cure temperature increased, the reaction rate increased and reaction order was almost constant. The activation energy of the system with HQ was lower about 13% and the reaction rate was higher than that of the system without HQ. It was because hydroxyl group of HQ formed a transition state with epoxide group and amine group and opened the epoxide ring easily and rapidly.

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Curing Reaction of Noble Liquid Crystalline Epoxy (LCE) with Azomethine/Aliphatic Amine (Azomethine 기를 가지는 신소재 액정 에폭시 (LCE)와 지방족 아민의 경화반응)

  • Kim, Sang-Uk
    • Korean Journal of Materials Research
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    • v.11 no.9
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    • pp.786-791
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    • 2001
  • $\alpha$,$\omega$-Bis(4-glycidyloxybenzylidene-4-aminophenyl)methane (BGBAM) was synthesized from the initial materials, 4-hydroxylbenzaldehyde (HBA), 4,4'-methylenedianiline (MDA) and epichlorohydrin. The DSC trace for BGBAM shows two endotherms associated with the liquid crystalline phase transition around $104.2^{\circ}C$ and the isotropic transition around $171.2^{\circ}C$, and it also has a broad exotherm in the range of $178~300^{\circ}C$ due to the anionic homopolymerization of BGBAM. DSC curve for the curing of BGBAM with hexamethylene diamine (HMD) shows an endothermic peak around $93^{\circ}C$ attributed to the melting of BGBAM. It also has three exothermic peaks around $128.4^{\circ}C$ and $180.2^{\circ}C$ associated with the epoxide-amine reaction and weak peak in the range of $200~263^{\circ}C$ related to the anionic homopolymerization between the unreacted epoxide groups. The activation energy values of cure reaction by Kissinger method are 66.5, 67.3 and 90.6 kJ/mol for $T_{pl},\; T_{p2}\; and \;T_{p3},\; respectively$. The kinetic parameters by isoconverional method are similar value to those from Kissinger method.

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A Study on Thermal Decomposition of RDX According to the Size using TGA (TGA를 이용한 RDX의 입자 크기에 따른 열적 분해 특성 연구)

  • Bum, Kil-Ho;Kim, Seung-Hee;Kim, Jin-Seuk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.1
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    • pp.81-85
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    • 2012
  • This work is related to study the thermal decomposition of 1,3,5-trinitro-1,3,5-triazacylohexane(RDX) by differential scanning calorimeter and thermo-gravimetry with Kissinger's & Iso-conversional method under nonisothermal conditions, with heating rate from 2 to $8^{\circ}C$/min or given heating rate. We calculated and compared activation energy with these two methods. Iso-conversional method is better than Kissinger's method to study decomposition mechanism. We also investigated activation energy and frequency factor by Kissinger's & Iso-conversional method with the influence of particle size. In case of single crystal, Cl-3(large crystal) has better thermal stability than Cl-5(small crystal). The activation energy increased according to the size of the particle size.

Non-isothermal TGA Analysis on Thermal Degradation Kinetics of Modified-NR Rubber Composites (비등온 TGA에 의한 개질NR고무복합재료지 열분해 Kinetics에 관한 해석)

  • Oh, Jeong-Seok;Lee, Joon-Mann;Ahn, Won-Sool
    • Polymer Korea
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    • v.33 no.5
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    • pp.435-440
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    • 2009
  • Thermal degradation behavior of CR (chloroprene) -modified NR (natural rubber) compounds, having different sulfur/accelerator compositions, was studied by non-isothermal TGA method. Data were analyzed using both Kissinger and Flynn-Wall-Ozawa analysis to assess the activation energies. Activation energy obtained from Kissinger analysis was $147.0{\pm}2.0$ kJ/mol for all samples, showing little effect of sulfur/accelerator composition changes in the samples. On the other hand, activation energy from Flynn-Wall-Ozawa analysis exhibited much variations with conversion, showing average value of $211.6{\pm}19.0$ kJ/mol. From the results, it was considered that whole thermal degradation processes of the samples were composed of complex multiple step processes, of which reaction mechanisms were different from each other.

Thermal Decomposition Behavior of LCT Composites Using Boron Nitride Filler (Boron Nitride를 함유한 열경화성 액정 에폭시의 열분해 거동)

  • Hwangbo, Sejin;Cho, Seung Hyun
    • Textile Science and Engineering
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    • v.55 no.1
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    • pp.35-40
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    • 2018
  • A liquid crystalline thermosetting-epoxy-based composite was fabricated using diglycidyl ether of 4,4'-biphenol, boron nitride as the filler, and sulfanilamide as the curing agent. To investigate the thermal behavior, thermogravimetric analysis was performed, and temperature differences of the sample were recorded when using 1.0-7.0 wt.% boron nitride. The activation energy for thermal decomposition was calculated using the Kissinger method and Flynn-wall method. The results showed that the activation energy was proportional to the amount of added filler.

Thermal Decomposition Behavior of Liquid Crystalline Epoxy-Based Composites (열경화성 액정 에폭시 매트릭스 복합재료의 열분해 거동 비교)

  • Park, Jonghyun;Cho, Seung Hyun
    • Textile Science and Engineering
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    • v.55 no.5
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    • pp.324-329
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    • 2018
  • Thermosetting liquid crystalline epoxy is an epoxy polymer that forms a liquid crystalline network structure upon curing. 4,4'-Diglycidyloxybiphenyl with an aromatic rigid-rod part such as a biphenyl group exhibits liquid crystallinity. Biphenol epoxy resin (BP), which is cured by using sulfanilamide, forms a liquid crystalline network by reacting the amine and epoxy ring of sulfanilamide and biphenol. In this experiment, silicon nitride (Si3N4) or aluminum nitride (AlN) was used as a filler. The activation energy required for the decomposition was calculated using the Kissinger method and the Flynn-wall method to confirm the thermal properties of the thermosetting liquid crystalline epoxy with silicon nitride. As a result, the activation energy required for decomposition of the composite increased with increasing silicon nitride content, and it was confirmed that silicon nitride increased the thermal stability of the thermosetting liquid crystalline epoxy.

Thermal Decomposition Activation Energy according to the Mesogen Structure of Liquid Crystalline Epoxy Composite with Aluminum Oxide Filler (산화 알루미늄을 분산시킨 열경화성 액정 에폭시의 Mesogen 구조에 따른 열분해 활성화 에너지)

  • Hyun, Ha Neul;Cho, Seung Hyun
    • Textile Science and Engineering
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    • v.56 no.5
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    • pp.314-320
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    • 2019
  • A liquid crystalline thermosetting-epoxy-based composite was fabricated using diglycidyl ether of 4,4'-bisphenol and diglycidyl ether of terephthalylidene-bis-(4-amino-3-methylphenol), with aluminum oxide as a filler, and sulfanilamide and 4,4'-diaminodiphenylethane as a curing agent. Thermogravimetric analysis was performed to investigate its thermal behavior, and temperature differences of the sample were recorded using 1.0-7.0 wt% aluminum oxide. The activation energy for thermal decomposition was calculated using the Kissinger method, and the Flynn-Wall method. The results showed that the activation energy was proportional to the amount of filler added.