• Title, Summary, Keyword: Kissinger method

Search Result 77, Processing Time 0.06 seconds

Study on Cure Behavior of Low Temperature and Fast Cure Epoxy with Mercaptan Hardener (Mercaptan 경화제에 의한 저온속경화 에폭시의 경화거동에 관한 연구)

  • Eom, Se Yeon;Seo, Sang Bum;Lee, Kee Yoon
    • Polymer Korea
    • /
    • v.37 no.2
    • /
    • pp.240-248
    • /
    • 2013
  • The curing behaviors of diglycidyl ether of bisphenol A (DGEBA) with mercaptan hardener were studied by the comparison with amine-adduct type hardener. Curing behaviors were evaluated by DSC at dynamic and isothermal conditions. In the DSC, the dynamic experiments were based on the method of Kissinger's equation, and the isothermal experiments were fitted to the Kamal's kinetic model. Activation energy of epoxy/amine-adduct type hardener was ca. 40 kcal/mol. As the functional group of mercaptan hardener, -SH increased, on epoxy/mercaptan hardeners, the activation energies decreased from 28 to 19 kcal/mol. Epoxy/amine-adduct type hardener was initiated at $90^{\circ}C$ or higher. However, epoxy/mercaptan hardeners reduced the initiation temperatures below $80^{\circ}C$ and shortened the durations of curing reaction within 10 min. We found out that the reaction kinetics of epoxy with mercaptan hardener followed the autocatalytic reaction models, and the maximum reaction rates were shown at the conversions of 20~40%.

Curing Behavior and Morphology of DGEBA/NMA/2,4,6-tris(dimethylaminomethyl) phenol System (DGEBA/NMA/2,4,6-tris(dimethylaminomehyl)phenol 시스템의 경화거동 및 Morphology)

  • 김민영;김성호;최영선;김원호;황병선
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • /
    • pp.118-121
    • /
    • 2001
  • The investigation of cure kinetics and morphology studies on DGEBA/PEI/Anhydride system were performed by differential scanning calorimetry and scanning electron microscopy. Autocatalystic kinetics model was applied by isothermal scan test. Ozawa method and Kissinger method was applied by temperature scan. Activation energy was 95kJ/mol for neat DGEBA/NMA, 120kJ/mol for DGEBA/PEI(10p.h.r.)/NMA. The generation of secondary phase of PEI was observed and its size was grown up by increasing contents of PEI.

  • PDF

A Study on Annealing of Fe-Si-B-Ni Amorphous Alloy (Fe-Si-B-Ni 비정질 합금의 어닐링에 관한 연구)

  • Kim, Shin-Woo;Song, Yong-Sul;Baek, Mu-Hum
    • Korean Journal of Materials Research
    • /
    • v.13 no.11
    • /
    • pp.721-724
    • /
    • 2003
  • A Fe-Si-B-Ni amorphous alloy manufactured by one roll melt-spinning method showed the crystallization temperature difference of a maximum $10^{\circ}C$ according to each lot. This temperature difference had a considerable influence on the annealing process to be conducted for obtaining the proper inductance of the alloy. The proper annealing temperature of the alloy was $480^{\circ}C$ and the annealing time increased as the crystallization temperature increased. The activation energy measured by Kissinger method increased as the crystallization temperature increased. Therefore, the annealing process must be adjusted by the crystallization temperature difference of the amorphous alloy.

Pyrolysis kinetics and microstructure of thermal conversion products on toluene soluble component from two kinds of modified pitch

  • Zhu, Yaming;Zhao, Xuefei;Gao, Lijuan;Cheng, Junxia
    • Carbon letters
    • /
    • v.28
    • /
    • pp.38-46
    • /
    • 2018
  • Modified pitch A (MPA) and modified pitch B (MPB) were prepared by oxidative polymerization and thermal polycondensation reaction with refined pitch as the raw material, respectively. The toluene soluble components (TS-1 and TS-2) were obtained by solvent extraction from MPA and MPB, separately. The Flynn-Wall-Ozawa method and Kissinger-Akahira-Sunose method were used to calculate the pyrolysis activation energy of TS. The Satava-Sestak method was used to investigate the pyrolysis kinetic parameters of TS. Moreover, the optical microstructure of the thermal conversion products (TS-1-P and TS-2-P) by calcination shows that TS-1-P has more contents of mosaic structure and lower contents of fine fiber structure than TS-2-P. The research result obtained by a combination of X-ray diffraction and the curve-fitting method revealed that the ratios of ordered carbon crystallite (Ig) in TS-1-P and TS-2-P were 0.3793 and 0.4417, respectively. The distributions of carbon crystallite on TS-1-P and TS-2-P were calculated by Raman spectrum and curve-fitting analysis. They show that the thermal conversion product of TS-2 has a better graphite crystallite structure than TS-1.

A Kinetic Studies of the Pyrolysis of Waste Plastic Based on the Thermogravimetic Analyses (폐플라스틱의 열분해 시 열중량 분석 및 동역학 연구)

  • Jung, Won Hak;Hwang, Hyeon Uk;Kim, Myung Gyun;Sun, JianFeng;Mutua, Nzioka Antony;Kim, Young Ju
    • Journal of the Korean Institute of Resources Recycling
    • /
    • v.24 no.5
    • /
    • pp.15-21
    • /
    • 2015
  • Waste plastic differs in its speed of combustion owing to its variety in composition as well as kinds of plastic. This study is aimed at examining the thermal weight analysis and determination of its kinetics in order to derive the design element in pyrolysis of RPF (Refused Plastic Fuel) as the plastic solid fuel. Based on the result of TGA (Thermogravimetric analysis), kinetic characteristics were analyzed by using Kissinger method which are the most common method for obtaining activation energy, and experimental conditions of TGA were set as follows: in a nitrogen atmosphere, gas flow rate of 20 ml/min, heating rate of $5{\sim}50^{\circ}C/min$, and maximum hottest temperature of $800^{\circ}C$. The method used for determining the property of waste plastic when thermally decomposed was thought feasible as the basic data in deciding the performance, design, and optimal operating condition of the reactor in the actual reactor.

Studies on Cure kinetics and Rheological Properties of Epoxy/Polyurethane Blend System (에폭시/폴리우레탄 블렌드계의 강화 동력학 및 유변학적 특성에 관한 연구)

  • 박수진;진중성;박병기
    • Textile Science and Engineering
    • /
    • v.37 no.8
    • /
    • pp.448-454
    • /
    • 2000
  • The effects of composition ratios of epoxy resin (EP) and polyurethane (PU) blends on cure kinetics and reheological properties were investigated. In this work, 20 phr of DDM (4,4'- diamino diphenyl methane) was used as a curing agent for epoxy resin. And the composition of EP/PU was varied within 100/0∼100/40 phr. The cure activation energies ($E_{a}$), which were obtained from dynamic DSC data by Kissinger method, were increased in 40 phr of PU in EP than in pure EP. The rheological properties of blend system were investigated under isothermal condition using a rheometer. Crosslinking activation energies ($E_{c}$) were also determined from the Arrhenius equation based on gel time and curing temperature. As a result, both gelaton time and crosslinking activation energy increased with increasling the content of PU. These results could be explained by the increase in reactivity between the hydroxyl group in EP and isocyanate group in PU, resulting in an increase in the crosslinking density.

  • PDF

Cure Characteristics of Metal Particle Filled DGEBA/MDA/SN/ zeolite Composite System for EMI Shielding

  • Cho, Young-Shin;Lee, Hong-Ki;Shim, Mi-Ja;Kim, Sang-Wook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.548-551
    • /
    • 1999
  • The cure characteristics of metal particle filled DGEBA/MDA/SN/ zeolite epoxy resin composite system for EMI shielding were investigated by dynamic DSC run method and FT-lR spectroscopy. As the heating rate increased, the peak temperature on dynamic DSC curve increased because of the rapid cure reaction. From the straight line of the Kissinger plot, the curing reaction activation energy and pre-exponential factor could be obtained. As the post-curing time at 15$0^{\circ}C$ increased, the glass increased the glass transition temperature or the thermal stability increased. When the post curing time is too long, the system filled with metallic Al particle can be thermally oxidized by the catalytic reaction of metal filler and the thermal stability of the composite for the EMI shielding application may be decreased.

  • PDF

Study on the Thermal Degradation of Poly(n-bulyl methacrylate) (Poly(n-butyl methacrylate)의 열분해에 관한 연구)

  • Kwak, Ki-Chul;Seul, Soo-Duk;Sohn, Jin-Eon
    • Elastomers and Composites
    • /
    • v.23 no.3
    • /
    • pp.213-222
    • /
    • 1988
  • The thermal decomposition of poly(n-butyl methacrylate)(Pn-BMA) was studied using a dynamic and isothermal thermogravimetry in nitrogen gas with 50ml/min at several heating rates from 1 to $20^{\circ}C/min$, and at several heating temperature from 320 to $370^{\circ}C$. The mathematical techniques used for calculation of activation energy were Kissinger, Anderson, Chatterjee-Conrad, Friedman, Fuoss, Ozawa and isolthermal method. The range of activation energies obtained using the several techniques was between 43 and 51Kcal/mol except Chatterjee-Conrad and this range agreed with each other very well. The thermal degradation of Pn-BMA was considered to be carried out by main chain scission.

  • PDF

The Crystallization Kinetics of CaO-MgO-Al2O3-SiO2 Glass System Using Thermal Analysis (열분석을 이용한 CaO-MgO-Al$_2$O$_3$-SiO$_2$의 결정화 기구의 연구)

  • 김형순
    • Journal of the Korean Ceramic Society
    • /
    • v.29 no.1
    • /
    • pp.9-14
    • /
    • 1992
  • Some of non-isothermal analysis methods are applied to CaO-MgO-Al2O3-SiO2 glass system to find the kinetics parameters of crystallisation, activation energy, Avrami component and frequency factor. The results using the non-isothermal analysis were compared to that of microstructure experiment. Analysis of the result has enabled to some methods to be to recommend as being the most appropriate equation to use in a glass system. It was shown that in the thermal analysis using the non-isothermal method of Kissinger, Augis-Bennett, Bansal, and Marotta, the calculation of activation energy is not much different, while Avrami component and frequency factor are different from applied each methods.

  • PDF

Effect of CaO Addition on Age Hardening Behavior of AZ91 Alloy (AZ91 합금의 시효경화 거동에 미치는 CaO 첨가의 영향)

  • Jun, Joong-Hwan
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.24 no.4
    • /
    • pp.193-198
    • /
    • 2011
  • Effect of CaO addition on age hardening response has been studied by using optical microscopy, scanning electron microscopy and differential thermal analysis in AZ91 and CaO-containing ECO-AZ91 alloys. After solution treatment, the ${\beta}$($Mg_{17}Al_{12}$) phase formed during solidification mostly disappeared in the microstructure in the AZ91 alloy, whereas numerous ${\beta}$ precipitates containing Ca were still observed in the ECO-AZ91 alloy due to its enhanced thermal stability. The ECO-AZ91 alloy showed the delayed peak aging time and higher peak hardness compared with those of the AZ91 alloy. The activation energies for ${\beta}$ precipitation calculated by means of Kissinger method increased from 71.4 to 85.6 kJ/mole by the addition of CaO, which implies that CaO plays a role in reducing ${\beta}$ precipitation rate in the AZ91 alloy.