• Title, Summary, Keyword: Decomposition behavior

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Flame-Retardant Properties and thermal Pyrolysis Behavior of Selected Flame-Retardant Cotton Cellulose (난연처리 면섬유의 난연성능과 열분해거동에 관한 연구)

  • 허영우;송석규
    • Textile Science and Engineering
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    • v.12 no.2
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    • pp.14-24
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    • 1975
  • The flame-retardant properties and thermal behavior of cotton finished with some selected flame retardants, organic nitrogen compound, organic phosphorus compound and inorganic halogen compound etc. were investigated. Total add-on of finish were determined and flammability properties were evaluated by the 45$^{\circ}$ angle method. Thermogravimetric analysis were used to study the thermal behavior of the cotton during pyrolysis. The thermogravimetric analysis curves were evaluated quantitatively for activation energy, total weight loss and char remaining after pyrolysis, and peculiarity point of pyrolysis. A study of the kinetics of decomposition for these systems indicates that activation energy was found to decrease with increasing flame retardency and an inverse relationship between activation energy and the residue remaining after pyrolysis was observed. Further, it has been observed that the addition to cellulose of any of the compounds lowers the onset temperature of decomposition and the temperature at which the first major weight loss begins, and the temperature decrease varies from compound to compound.

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Thermal Decomposition of Tetrakis(ethylmethylamido) Titanium for Chemical Vapor Deposition of Titanium Nitride

  • Kim, Seong-Jae;Kim, Bo-Hye;Woo, Hee-Gweon;Kim, Su-Kyung;Kim, Do-Heyoung
    • Bulletin of the Korean Chemical Society
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    • v.27 no.2
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    • pp.219-223
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    • 2006
  • The thermal decomposition of tetrakis(ethylmethylamido) titanium (TEMAT) has been investigated in Ar and $H_2$ gas atmospheres at gas temperatures of 100-400 ${^{\circ}C}$ by using Fourier Transform infrared spectroscopy (FTIR) as a fundamental study for the chemical vapor deposition (CVD) of titanium nitride (TiN) thin film. The activation energy for the decomposition of TEMAT was estimated to be 10.92 kcal/mol and the reaction order was determined to be the first order. The decomposition behavior of TEMAT was affected by ambient gases. TEMAT was decomposed into the intermediate forms of imine (C=N) compounds in Ar and $H_2$ atmosphere, but additional nitrile (RC$\equiv$N) compound was observed only in $H_2$ atmosphere. The decomposition rate of TEMAT under $H_2$ atmosphere was slower than that in Ar atmosphere, which resulted in the extension of the regime of the surface reaction control in the CVD TiN process.

Synthesis and Optical Recording Properties of Coupled Hemicyanine Salts for DVD-R

  • Lee, Chul-Joo;Min, Kyung-Sun;Park, Ki-Hong
    • Journal of Photoscience
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    • v.10 no.2
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    • pp.209-214
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    • 2003
  • A series of coupled-hemicyanine dyes with alkylene spacer were successfully synthesized by a reaction of coupled aldehydes with corresponding salts, respectively. These coupled dyes had more excellent thermal properties (high decomposition temperature, stiff decomposition behavior) and higher molar absorption properties than an uncoupled dye. The coupled dyes with perchlorate anions showed the strongest exothermic decomposition while those with hexafluorophosphorate anions showed endothermic decomposition. As the coupling length (n=3, 4, 5, 6) increased, thermal properties decreased and dyes with even spacer was more thermally stable than dyes with odd spacer. Among several coupled dyes, C4-NP-ClO4 and C4-Cl-ClO4 exhibited the best recording properties with the lowest jitter value of 7.5∼9.5% in authoring disc.

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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.

Studies on the Composition analysis of Oak Mushroom (Lentinula edodes) Cultural Waste (표고버섯 재배용 참나무 폐골목의 화학적 성분분석)

  • Lee, Min-Woo;Seo, Yung-Bum
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • pp.222-228
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    • 2008
  • The chemical composition and thermal, crystal characterization of oak mushroom waste were investigated in comparison with those normal oak wood for utilization of cellulose from oak mushroom waste. The oak mushroom waste contained a higher percentage of ash, and hot water extractives than oak wood. This results indicated that the materials inside the body are easily decomposed during the oak mushroom cultivation. The lower percentage of holocellulose and a-cellulose of oak mushroom waste caused by fungal decomposition too. Whereas, the thermal decomposition behavior and crystallinity of oak mushroom waste was similar to that of normal oak wood, which indicated that the cellulose characterization of oak mushroom waste is resistant to fungal decomposition. In additionally, a degree of polymerization of oak mushroom waste must be investigate for examination of cellulose crystalline characterization, especially.

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Synthesis of Ti-doped $Li_3AIH_6$ powders by mechanochemical reaction and their thermal decomposition behavior (기계화학반응법을 이용한 Ti-doped $Li_3AIH_6$ 분말의 합성과 열분해 특성)

  • Lee, E.K.;Kim, Y.K.;Cho, Y.W.;Yoon, J.K.
    • Transactions of the Korean hydrogen and new energy society
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    • v.16 no.1
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    • pp.92-101
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    • 2005
  • [ $Li_3AlH_6$ ] (5.6wt% theoretical hydrogen storage capacity) powders with and without Ti-containing dopants have been successfully synthesized by mechanochemical reaction near room temperatures from mixtures of LiH and $LiAlH_4$ powders. It has been observed that single phase $Li_3AlH_6$ could be obtained within 2-3 hours of milling, but the addition of reactive $TiCl_2\;or\;TiCl_3$ to the starting mixtures. caused partial decomposition of $LiAlH_4$ into LiCl and free Al with gaseous $H_2$. By addition of these reactive dopants to the as-synthesized $Li_3AlH_6$, this problem could be solved. The addition of 2 mol% $TiCl_2\;or\;TiCl_3\;to\;Li_3AlH_6$ decreased the decomposition start temperature up to 30-50$^{\circ}C$, while that of Ti or $TiH_2$ did not change the thermal decomposition behavior of $Li_3AIH_6$.

Thermal Behavior of Dickite (딕카이트의 열적 특성 연구)

  • 조현구
    • Journal of the Mineralogical Society of Korea
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    • v.12 no.1
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    • pp.11-22
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    • 1999
  • Thermal behavior of dickite was studied by thermal analysis, X-ray diffraction analysis, electron microprobe analysis, and scanning electron microscopy, Dickite has an endothermic peak at about$ 650^{\circ}C$ and an exothermic one at $960^{\circ}C$ in the differential thermal analysis. The endothermic reaction is assigned to the decomposition of dickite to meta-dickite. Hydroxyl radicals are removed from dickite structure by the reaction, resulting in the weight loss about 10.5~14.5% and appearance of a 14$\AA$ phase different from other kaolin minerals. The reaction slowly proceed in the range of $200^{\circ}C$. As the completion of decomposition, aciclular mullite forms at the expense of meta-dickite plates with random crystallographic relationship. Mullites have diverse silica versus alumina ratio. The exothermic reaction without weight loss seems to be due to the formation of spinel and amorphous silica. The spinel phase shows cryptocrystalline globular morphology accompanying a little amount of silica. From spinel phase shows cryptocrystalling globular morphology accompanying a little amount of silica. From this work, it is suggested that mullite is formed from meta-dickite much lower temperature than the reported one in the previous works.

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