• Title/Summary/Keyword: Pyrolysis gas chromatography

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On the Pyrolysis of Polymers II. Identification of the Products from Polymer Pyrolysis by Gas Chromatography (高分子物質의 熱分解에 關한 硏究 (第2報) Gas Chromatography 에 依한 熱分解生成物의 檢索)

  • Chwa-Kyung Sung
    • Journal of the Korean Chemical Society
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    • v.7 no.2
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    • pp.106-114
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    • 1963
  • The products from polymer pyrolysis at $450^{\circ}$ are cooled with ice, then liquid and gaseous portions are analysed by gas chromatography. Di-2-ethyl hexyl sebacate column, silicone oil column, silica gel column and tetraethyleneglycol dimethylether column, which was most effective for the separation of hydrocarbon gases, are used. Identification of isomers could be secured more effectively by gas chromatography than mass spectrometry. Elucidation of the mechanism for thermal decomposition of polymers could be done through the identification of pyrolysis products. Although more extensive work is needed, some patterns of polymer pyrolysis are discussed.

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On the Pyrolysis of Polymers III. Identification of Gases from Rubber Pyrolysis by Gas Chromatography (高分子物質의 熱分解에 關한 硏究 (第3報) 合成고무類의 熱分解生成物의 Gas Chromatography에 의한 檢索과 合成고무 確認에의 利用)

  • Chwa-Kyung Sung
    • Journal of the Korean Chemical Society
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    • v.7 no.2
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    • pp.115-121
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    • 1963
  • Aliphatic hydrocarbon gases from rubber pyrolysis have been identified by gas chromatography with tetraethyleneglycol dimethylether column. Rubbers used in this work are polyisoprene, SBR, NBR, polybutadiene, buthyl rubber, polychloroprene and polyurethane rubber. The chromatogram is characteristic for each polymer. Author proposes a method of identification of synthetic rubbers by gas chromatograph of pyrolyzed gas. Sample is pyrolyzed at $450^{\circ}C$ under nitrogen or more effectively helium and gaseous portion, which eliminated liquid condensate, is passed to the column. The appearance of exclusively large peak of isoprene, isobutylene and carbon dioxide shows the presence of polyisoprene, polyisobutylene and polyurethane, respectively. Large peak of butadiene will appear in case of polybutadiene, SBR and NBR, but SBR can be identified through the styrene peak in gas chromatogram of liquid pyrolyzate and NBR can be identified by the evolution of hydrogen cyanide during pyrolysis. Polychloroprene is identified by the evolution of hydrogen chloride. This method could be applied to the identification of copolymer or polymer blend.

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Study on Analysis of Vulcanized Rubber by Pyrolysis-Gas Chromatography(I) (Vulcanizates of NR BR and SBR) (Pyrolysis-Gas Chromatography를 이용한 가황 고무의 열분석에 관한연구(I) (NR, BR 및 SBR의 가황체))

  • Huh, D.S.;Kim, J.S.;Kim, K.J.;Ahn, B.K.;Suh, S.K.;Han, O.K.
    • Elastomers and Composites
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    • v.22 no.1
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    • pp.11-19
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    • 1987
  • A coil pyrolyzer and processor-controlled gas chromatograph were used for analysis of rubber for compounding ratio of the single and blend rubber vlucanizates. Variables such as sample size, pyrolysis temperature, time allowed for pyrolysis, the column packing material, its length and programmable temperature for gas chromatography were examined to obtain optimum condition for application to NR, BR and SBR blends. By application fixed conditions, three kinds of standard curves were finally obtained from thirty samples of blend vulcanizates which were prepared in the pilot plant, NIRI. It is possible to determine rubber composition and their ratio in NR, BR and SBR products by pyrolysis.

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Analytical Method for Determination of Microstructure of SBR and SBR Content in Blended Rubber Composites Using Pyrolytic Technique

  • Eunji Chae;Sung-Seen Choi
    • Elastomers and Composites
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    • v.57 no.4
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    • pp.188-196
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    • 2022
  • Styrene-butadiene rubber(SBR) is a copolymer of styrene and butadiene. It is composed of 1,2-unit, 1,4-unit, and styrene, and its properties are dependent on its microstructure. In general, rubber composites contain a single rubber or a blended rubber. Similarly, SBR is used by mixing with natural rubber(NR) and butadiene rubber(BR). The composition of a rubber article affects its physical and chemical properties. Herein, an analytical method for determining the microstructure of SBR using via pyrolysis is introduced. Pyrolysis-gas chromatography/mass spectrometry is widely used to analyze the microstructure of polymeric materials. The microstructure of SBR can be determined by analyzing the principal pyrolysis products formed from SBR, such as 4-vinylcyclohexene, styrene, 2-phenylpropene, 3-phenylcyclopentene, and 4-phenylcyclohexene. An analytical method for determining the composition of SBR/NR, SBR/BR, and SBR/NR/BR blends via pyrolysis is introduced. The composition of blended rubber can be determined by analyzing the principal pyrolysis products formed from each rubber component.

On the Pyrolysis of Polymers IV. Pyrolysis of Polythylene and Polypropylene (高分子物質의 熱分解에 關한 硏究 (第4報) Polyethylene 및 Polypropylene의 熱分解에 關하여)

  • Chwa-Kyung Sung;Icksam Noh;Jung Yup Kim;Sung Bong Chang
    • Journal of the Korean Chemical Society
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    • v.7 no.2
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    • pp.122-127
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    • 1963
  • Pyrolysis fo polyethylene and polypropylene has been studied in order to clarify the mechanism of chain scission and effect of oxygen on degradation. Rate of weight decrease was measured under nitrogen and air atmosphere at constant temperature for the samples of high density polyethylene, low density polyethylene and isotactic polypropylene, and then gaseous hydrocarbons produced from pyrolysis were analysed by gas chromatography. Although there is little substantial difference between composition of hydrocarbon gases from pyrolysis of high density polyethylene and low density polyethylene except some difference in quantity of total gas produced, gas composition from polypropylene pyrolysis differs from that of polyethylene pyrolysis. Gases from pyrolysis under air contain much more unsaturated hydrocarbons than those from pyrolysis under inert gas.

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Transformation of dissolved organic matter in a constructed wetland: A molecular-level composition analysis using pyrolysis-gas chromatography mass spectrometry

  • Park, Jongkwan;Choi, Mijin;Cho, Jaeweon;Chon, Kyongmi
    • Environmental Engineering Research
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    • v.23 no.4
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    • pp.390-396
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    • 2018
  • This study investigated the transformation of dissolved organic matter (DOM) in a free-water surface flow constructed wetland. Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) coupled with preparative high-performance liquid chromatography (prep-HPLC) was used to analyze the compositions of biopolymers (polysaccharides, amino sugars, proteins, polyhydroxy aromatics, lipids and lignin) in DOM according to the molecular size at three sampling points of the water flow: inflow, midflow, and outflow. The prep-HPLC results verified the decomposition of DOM through the decrease in the number of peaks from three to one in the chromatograms of the sampling points. The Py-GC/MS results for the degradable peaks indicated that biopolymers relating to polysaccharides and proteins gradually biodegraded with the water flow. On the other hand, the recalcitrant organic fraction (the remaining peak) in the outflow showed a relatively high concentration of aromatic compounds. Therefore, the ecological processes in the constructed wetland caused DOM to become more aromatic and homogeneous. This indicated that the constructed wetland can be an effective buffer area for releasing biochemically stable DOM, which has less influence on biological water quality indicators, e.g., biochemical oxygen demand, into an aquatic ecosystem.

Direct Analysis of Organic Additives in Cured Rubber by Pyrolysis-Gas Chromatography/Mass Spectrometry (열분해-가스크로마토그래피/질량분석법에 의한 가황고무중의 유기첨가제의 직접분석)

  • Kim, Seung Wook;Heo, Gwi Suk;Lee, Gae Ho
    • Journal of the Korean Chemical Society
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    • v.41 no.10
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    • pp.524-534
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    • 1997
  • Analysis of additives in cured rubber is often a difficult task for analytical chemists because of a wide variety of complex components. Conventional analyses of additives and rubbers have been done in multistep, off-line processes with large sample size and extensive sample preparations. The coumarone-indene resin, resorcinol-formaldehyde resin, and prevulcanization inhibitor have been characterized by their pyrolysis pathways and mass spectra of characteristic pyrolyzates. Pyrolysis Gas Chromatography/Mass Spectrometry (Py-GC/MS) was used in the identification of additives without any sample pretreatment. This result shows that several organic additives in cured rubber can be directly analyzed.

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Identification of Marker Compounds for Discriminating between Embryogenic and Nonembryogenic Calluses of Higher Plants Using Pyrolysis Gas Chromatography Mass Spectrometry and Genetic Programming

  • Kim Suk-Weon;Ban Sung-Hee;Yoo Ook-Joon;Liu Jang-Ryol
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.1
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    • pp.38-42
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    • 2006
  • When whole cells are subjected to pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) analysis, it provides biochemical profiles containing overlapping signals of the majority of compounds. To determine marker compounds that discriminate embryogenic calluses from nonembryogenic calluses, samples of embryogenic and nonembryogenic calluses of five higher plant species were subjected to Py-GC/MS. Genetic programming of Py-GC/MS data was able to discriminate embryogenic calluses from nonembryogenic calluses. The content ratio of 5-meyhyl-2-furancarboxaldehyde and 5-(hydroxymethyl)-2-furancarboxaldehyde was greater in nonembryogenic calluses than in embryogenic calluses. However, the content ratio of phenol, p-cresol, and $^1H-indole$ in embryogenic calluses was 1.2 to 2.4 times greater than the ratio in nonembryogenic calluses. These pyrolysates seem to be derived from the components of the cell walls, which suggests that differences in cell wall components or changes in the architecture of the cell wall playa crucial role in determining the embryogenic competence of calluses.

Determination of Tire Tread Rubber in the Atmospheric Particulate Matters by Pyrolysis-Gas Chromatography (열분해 가스크로마토그래피에 의한 대기입자상 물질중의 타이어 트래트 고무성분의 정량)

  • 李龍根;金萬九;金南勳;黃圭子
    • Journal of Korean Society for Atmospheric Environment
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    • v.3 no.2
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    • pp.39-45
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    • 1987
  • Rubber particles emitted from automobile tire tread by abrasion were collected by Andersen sampler with atmospheric dusts. The samples of atmospheric dusts at each stage were analysed for rubber particles by Curie point pyrolysis-gas chromatography with Apiezon grease L column. Pyrolysis was done at 740$^circ$C for 5 seconds. In the pyrogram, NR rubber (bus and truck tire tread) was determined by isoprene peak, and SBR rubber (passenger car tire tread) was determined by styrene peak simultaneously. The size distribution of rubber particles was proportioned with the size of rubber particles. The concentrations of NR and SBR rubber were 0.23 $\mug/m^3$ and 1.31 $\mug/m^3$, respectively, in the atmospheric dusts which were collected from the street in front of Yonsei University on April 1986. The ratio of tire tread rubber in the atmospheric dusts was about 0.63%.

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Study on Oil Production from Pyrolysis of Mixed Plastic Waste Using Multidimensional Chromatography (Multidimensional Chromatography/Mass Spectrometry를 이용한 혼합 폐플라스틱의 열분해 오일 특성 평가에 관한 연구)

  • 김석완
    • Journal of Environmental Science International
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    • v.11 no.4
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    • pp.375-382
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    • 2002
  • The total hydrocarbon distribution of oil products obtained from the pyrolysis of four kinds of mixtures of polyethylene-polystyrene waste has been studied by multidimensional chromatography(high performance liquid chromatography followed by capillary gas chromatography)/mass spectrometry. Saturated, unsaturated and aromatic hydrocarbons in oil products were selectively pre-separated according to structural groups by HPLC and the weight fraction of each group was estimated by analysis of each component using GC-FID response factors. The hydrocarbon distribution of aliphatic fraction consists of $C_{5}$ to $C_{25}$ saturated and unsaturated hydrocarbons. And that of aromatics fraction consists of benzene, toluene, xylene, styrene, propenyl benzene, naphthalene, and some of derivatives. Pyrolysis temperature did not affect the ratio of total weight fraction of aliphatic over aromatic hydrocarbon distribution in case of PS only and PE-PS mixtures (1:1 and 1:4 wt. ratio) as a feed while affected the ratio of total wt. fraction in case of PE only. The optimal temperature for the maximum oil production was $600^{\circ}C$ for pyrolysis of PS and 1:1 and 1:4 mixtures of PE and PS. The optimal condition for aromatic recovery was $600^{\circ}C$ with 1:1 mixture of PE and PS. In this condition, aromatic was produced up to 90% of total oil product. The maximum yield of toluene, xylene, styrene, and propenyl benzene were 8.6, 8.9, 51.0 and 7.4% of feed for pyrolysis PS at $700^{\circ}C$, respectively. However, only 1.3% naphthalene was recovered at $700^{\circ}C$ with 1:1 PE:PS(by wt.).