• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.59-66
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• 2006

The thermal properties of wood flour, Hwangto, and maleated polyethylene (MAPE) reinforced HDPE composites were investigated in this study. The thermal behavior of reinforced wood polymer composites was characterized by means of thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses. Hwangto and MAPE were used as an inorganic filler and a coupling agent, respectively. According to TGA analysis, the increase of wood flour level increased the thermal degradation of composites in the early stage, but decreased in the late stage. On the other hand, Hwangto reinforced composites showed the higher thermal stability than virgin HDPE, from the determination of differential peak temperature ($DT_p$). Decomposition temperature of wood flour and/or Hwangto reinforced composites increased with increase of heating rate. From DSC analysis, melting temperature of reinforced composites little bit increased with the addition of wood flour or Hwangto. As the loading of wood flour or Hwangto to HDPE increased, overall enthalpy decreased. It showed that wood flour and Hwangto absorbed more heat energy for melting the reinforced composites. Hwangto reinforced composites required more heat energy than wood flour reinforced composites and virgin HDPE. Coupling agent gave no significant effect on the thermal properties of composites. Thermal analyses indicate that composites with Hwangto are more thermally stable than those without Hwangto.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.1
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• pp.1-7
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• 2004

The precipitation of ultra fine ammonium perchlorate(UFAP) crystals from the N-methyl pyrrolidone(NMP) solutions of ammonium perchlorate(AP) was studied. The characteristics of the precipitated crystals were investigated by means of scanning electron micrograph(SEM), X-ray diffraction(XRD), and thermogravimetric analysis(TGA). When chloroform, methylene chloride and toluene were the precipitants, the product crystals had a mean particle size less than 2$\mu\textrm{m}$. The crystallographical property and thermal decomposition behavior of the prepared UFAP were almost the same as those of the commercial AP.

• Carbon letters
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• v.10 no.1
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• pp.5-8
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• 2009

We measured the non-carbon content of single-walled carbon nanotubes (SWCNTs) in SWCNT soot using thermogravimetric analysis. The weight increased percentage by the oxidation of metal in the raw soot is well obtained by TGA graph which was confirmed with ICP-AES, XRD, and XPS. This work will be very useful for the purity precise evaluation of SWCNT with UN-vis-NIR spectroscopy.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.4
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• pp.23-30
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• 1999

The thermal decomposition of phase stabilized ammonium nitrate(PSAN) was studied by means of thermogravimetric analysis(TGA). In this study, potassium nitrate and zinc oxide were used as the phase stabilizers in the range of contents from 0 wt.% to 8 wt.%. The kinetics and mechanism for the decomposition were evaluated using integral methods. It was found that the thermal kinetic parameters such as activation energy(I) and frequency factor(A) increase with the increase of the stabilizer contents, and the mechanism of decomposition also changes.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.341-342
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• 2008

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.217-226
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• 2009

The combustion reaction of polyvinylchloride(PVC) 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, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The combustion reaction of PVC proceeded in two steps; the first step was caused by the dehydrochlorination process in PVC, and the second step by the combustion of polyene. 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.56 no.1
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• pp.1-5
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• 2021

Tire and road wear particles (TRWPs) were collected from road dust and thermogravimetric analysis (TGA) was performed to measure the content of tire wear particles (TWPs) in the TRWPs. The TGA thermograms of TRWPs showed two weight loss steps associated with polymer decomposition including weight loss after 480℃ which may be due to road wear particles. Different samples gave different TGA thermograms because the types and contents of the road wear particles attached to the TWPs should be different from each other, and each TWP might have different composition. The TGA results of the model asphalt pavement wear particles, with (volatile organics + polymers + carbon black) : ash = 33.5 : 66.5, was applied to the TRWP results, and the TWP contents of TRWPs were found to be 50-65%. The zinc oxide content in the rubber compound was negligible.

• Macromolecular Research
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• v.17 no.3
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• pp.149-155
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• 2009

The thermal decomposition behavior and degradation characteristics off our different thermotropic liquid crystalline polymers (TLCPs) were studied. The thermal decomposition behavior was determined by means of thermogravimetric analysis (TGA) at different heating rates in nitrogen and air. The order of the thermal stability was as follows: multi-aromatic polyester > hydroxybenzoic acid (HBA)/hydroxynaphthoic acid (HNA) copolyester > HNA/hydroxyl acetaniline (HAA)/terephthalic acid (TA) copolyester > HBA/Poly(ethylene terephthalate) (PET) copolyester. The activation energies of the thermal degradation were calculated by four multiple heating rate methods: Flynn-Wall, Friedman, Kissinger, and Kim-Park. The Flynn-Wall and Kim-Park methods were the most suitable methods to calculate the activation energy. Samples were exposed to an accelerated degradation test (ADT), under fixed conditions of heat ($63{\pm}3^{\circ}C$), humidity ($30{\pm}4%$) and Xenon arc radiation ($1.10\;W/m^2$), and the changes in surface morphology and color difference with time were determined. The TLCPs decomposed, discolored and cracked upon exposure to ultraviolet radiation.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.155-160
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• 2007

This study was conducted to find out the chlorine removal characteristics of waste plastic mixture by pyrolysis process with thermogravimetric analysis(TGA) and a lab-scale pyrolyzer. The material used as plastic wastes were PE (Poly-ethylene), PP (Poly-prophylene), and PVC (Poly Vinyl Chloride). Experimental procedure were composed of three steps; 1st step: TGA of PVC, PP and PE, 2nd step: chlorine removal rate of PVC in a lab-scale pyrolyzer, 3rd step: chlorine removal rate of PVC-PE and PVC-PP mixture in a pyrolyzer. Through the results of TGA, we can estimate the basic pyrolysis characteristics of each plastic, and then we can also derive the design parameters and operating conditions of the lab-scale pyrolyzer. The results can be used as primary data for designing a system to produce RPF (Refuse Plastic Fuel), a waste incinerator and a pyrolysis/gasification process.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.292-295
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• 2005

The curing time of the phenolic resin for the processing of brake pad is very important factor for reducing the processing cost. The curing time could be investigated by examining the reaction time of the phenolic resin and hexamethylenediamine. The reaction time has been studied by FT-IR, Differential Scanning Calolimetric Analysis (DSC), and Thermogravimetric Analysis (TGA).