• Elastomers and Composites
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• v.58 no.2
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• pp.81-86
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• 2023

Asphalt pavements are generally composed of fine and coarse aggregates, bitumen, and modifier. Asphalt pavement wear particles (APWPs) are produced by friction between the road surface and the tire tread, and they flow into the environment such as rivers and oceans. Model APWPs were prepared and a single APWP of 212-500 (S-APWP) and 500-1000 ㎛ (L-APWP) was analyzed using thermogravimetric analysis (TGA) to investigate inhomogeneity in the compositions of the APWPs. The reference TGA thermogram was built using thermograms of the raw materials and formulation of the model asphalt pavement. The compositions of the APWPs were different from each other. Ash contents of the APWPs were lower than expected. Inhomogeneity in the total contents of bitumen and modifier was more severe than that in the other components. The inhomogeneity of the S-APWPs was more severe than that of the L-APWPs.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.8 no.2
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• pp.18-26
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• 2002

Films of methylcellulose(MC), chitosan and their blends were prepared using water and acid solution as a solvent. The transition behavior and miscibility of polymers and their blends were characterized by dynamic mechanical analysis(DMA) and thermogravimetric analysis(TGA). The DMA analysis of PEG400/MC blends has shown that PEG400 was compatible with MC and was effective plasticizer since the curves of $tan{\delta}$ against temperature exhibited single peak, corresponding to single glass transition temperature, which were displaced to lower values with increasing PEG400 content. Results of DMA analysis and TGA analysis of MC/chitosan blends indicate that there are some miscibility between MC and chitosan in the blends, attributed to the similarities between two polysaccharides and interactions of two polymers in the blends. The inclusion of PEG400 in the blends increase the miscibility between two components in the blends.

• 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.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.111-120
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• 2008

The combustion reaction of polypropylene was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C/min$. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Freeman-Carroll, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

• Elastomers and Composites
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• v.51 no.3
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• pp.206-211
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• 2016

Experimental error sources for thermogravimetric analysis (TGA) of poly(ethylene-co-vinyl acetate) (EVA) were investigated and sample preparation method to reduce the experimental error was suggested. Maximum dissociation temperatures of EVA for the first and second dissociation reactions ($T_{m1}$ and $T_{m2}$, respectively) were measured. By decreasing the weight of raw EVA, the $T_{m1}$ increased but the the $T_{m2}$ decreased. When weight of the raw EVA was over 10 mg, the TGA curve showed abnormal behaviors. The abnormal TG behaviors were explained by gathering and instantaneous evaporation of acetic acid formed by deacetylation of the VA unit. When TGA analysis of EVA was performed using untreated (raw) EVA, the experimental errors were about 1%. In order to eliminate the abnormal TG behaviors and to reduce the experimental errors, EVA film made by solvent casting was used. For the treated EVA (EVA film), the abnormal TG behaviors did not appear, the $T_{m1}$ decreased by about $2^{\circ}C$ but the $T_{m2}$ increased by about $6^{\circ}C$, and the experimental errors were reduced by 0.5%.

• Elastomers and Composites
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• v.50 no.1
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• pp.18-23
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• 2015

Vinyl acetate (VA) contents of poly(ethylene-co-vinyl acetate) (EVA) analyzed by infrared spectroscopy (IR), nuclear magnetic spectroscopy (NMR), and thermogravimetric analysis (TGA) were compared. Four grade EVAs supplied by Aldrich Co. and four grade EVAs manufactured by DuPont Co. were used. For IR analysis, VA contents were determined using calibration curve (absorbance ratio of $1739cm^{-1}/2922cm^{-1}$ or $609cm^{-1}/1464cm^{-1}$) of reference EVAs. Correlation coefficients of the calibration curves were not sufficiently high ($r^2{\leq}0.96$). For NMR analysis, VA contents were determined using peaks of $CH_3$, $CH_2$, and CH. VA contents determined by NMR analysis were less than those marked by suppliers more than 10%. For TGA, VA contents were determined using weight loss through deacetylation. VA contents determined by TGA were slightly different with those marked by suppliers. Difference in the VA contents determined by different analytical methods was discussed, and difference in the analytical results according to the EVA suppliers was also examined.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.156-159
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• 2006

Gasification and melting method is one of the most potential means for waste treatment process with low emission of fly ash or heavy metal, dioxin and high possibility of using slags as resources. Moisture contents influences directly a gasification characteristics of waste. So it is necessary to investigate the effect of moisture contents in gasification. But it is hard to consider the effect of moisture contents, using samples of powder form of Milligram's order in existing thermogravimetric analyser. Therefore, we made a thermogravimetric analysis device to applicate samples of Gram's order. Gasification characteristics are typically reported with result from thermogravimetric analysis date for wood and RDF samples along with changing moisture contents. It is discussed the way to apply these analysis results to gasification and melting furnace.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.59-67
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• 2001

Rice husk flours were analyzed by chemical composition and thermogravimetric methods in nitrogen atmosphere to discuss its feasibility as a raw material for manufacturing agricultural lignocellulosic fiber-thermoplastic polymer composite. It was revealed in the chemical composition analysis that rice husk flour was composed of moisture, 5.0%; lignin, 21.6%; holocellulose, 60.8%; ash, 12.6%. In the thermogravimetric analysis (TGA), thermal decomposition behavior of rice husk flour from room temperature to $350^{\circ}C$ was similar to that of wood flour, but rice husk flour was more thermally stable from 350 to $800^{\circ}C$ than wood flour because of higher silica content in the rice husk flour and smaller particle size of rice husk flour. The activation energy of thermal decomposition was evaluated using Flynn & Wall expression. As the thermal decomposition proceeded in rice husk flour, the activation energy of thermal decomposition appeared almost constant up to ${\alpha}=0.25$, but thereafter increased. Activation energy of thermal decomposition in wood flour, however, decreased steeply up to ${\alpha}=0.3$, but thereafter remained almost constant. From the results, rice husk flour was thought be a substitute for wood flour in manufacturing agricultural lignocellulosic fiber-thermoplastic polymer composite in the aspect of thermal decomposition.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.572-579
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• 2017

Determination of the wood content in wood plastic composite (WPC) is crucial to form reliable WPC market. WPC with simple formulation consisting of only two components (wood flour and polypropylene) was examined using thermogravimetric analysis (TGA) and accelerator mass spectrometry (AMS) for determining wood content in the WPC. TGA method using derivative peak temperature (DTp) of polypropylene under low heating rate ($5^{\circ}C/min$) showed more reliable calibration curve and lower error factor compared to method of using the percentage of weight loss of wood flour. In addition, AMS using bio-based carbon content showed greater reliability for the determination of wood content in the WPC in comparison with the TGA method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.22-25
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• 2005

The thermal degradation of carbon/phenolic composite have been studied at high temperature by using thermogravimetric (TGA). A heating .ate of 5, 10, 15, 30 and $50^{\circ}C/min$ was used for the determination of thermal decomposition parameters of composite materials at high-temperature service. It has been shown that as the heating rates is increased, the peak decomposition rates are occur at higher temperature. Based on results of thermogravimetric analysis, the pyrolysis process is analyzed and physical and mathematical models for the process are proposed. The thermal analysis also has been conducted using transient heat conduction and the in-depth temperature distribution and the density profile were evaluated along the solid rocket nozzle. As a future effort the thermal decomposition parameter determined in this investigation will be used as input to thermal and mechanical analysis when subjected to solid rocket propulsion environment.