다양한 측정법을 이용한 담마검의 연화점 분석 연구

박현진(Hyeonjin Park),윤소정(Sojeong Yoon),정향연(Hyangyeon Jeong),반영란(Younglan Ban),홍성준(Seong Jun Hong),조성민(Seong Min Jo),이양봉(Yang Bong Lee),신의철(Eui-Cheol Shin) 한국식품영양과학회 2023 한국식품영양과학회지 Vol.52 No.12

This study was conducted to suggest the most appropriate method for determining the softening point of dammar gum. The softening point value of dammar gum is presented in the Food Additives Code. To determine the softening point, the test was conducted using the ring and ball method for manual-heating, automatic-heating, and automatic-measurement presented in the Food Additives Code of Korea. Analytical method validation was conducted to ensure a precise measurement of the softening point. The softening point of dammar gum was 77.41℃ with a %RSD of 0.22∼5.59% in the manual-heating method, 87.20℃ with a %RSD of 0.43∼1.68% in the automatic-heating method, and 87.33℃ with a %RSD of 2.33% in the automatic-measurement method. The results of this study confirmed the precision of the experimental methods. It was confirmed that the automatic-heating method and automatic-measurement method, which provided results within the range (86.00∼90.00℃) of the softening point value of dammar gum provided in the current Food Additives Code, are appropriate for softening point analysis.

석탄계 타르의 열처리 중 압력변화에 따른 변성 콜타르 핏치의 미세구조 및 물성 변화

고효준,정성모,한지훈,박창욱,김명수,임연수,Ko, Hyo Joon,Chung, Sung Mo,Han, Ji Hoon,Park, Chang Uk,Kim, Myung-Soo,Lim, Yun-Soo 한국재료학회 2014 한국재료학회지 Vol.24 No.6

Coal-tar pitch, a feedstock which can be heat-treated to create graphite, is composed of very complex molecules. Coal-tar pitch is a precursor of many useful carbon materials (e.g., graphite, carbon fibers, electrodes and matrices of carbon/carbon composites). Modified coal-tar pitch (MCTP) was prepared using two different heat-treatment methods and their properties were characterized and compared. One was prepared using heat treatment in nitrogen gas; the other was prepared under a pressure of 350 mmHg in air. The MCTPs were investigated to determine several properties, including softening point, C/H ratio, coke yield, formation of anisotropic mesophase and viscosity. The MCTPs were subject to considerable changes in chemical composition due to condensation and polymerization in the used-as-received coal-tar pitch after heat-treatment under different conditions. The MCTPs showed considerable increases in softening point, C/H ratio, and coke yield, compared to those of as-received coal-tar pitch. The MCTP formed by heat-treatment in nitrogen showed isotropic phases below $350^{\circ}C$ for 1 h of soaking time. However, MCTP heat-treated under high pressure (350 mmHg) showed isotropic phases below $300^{\circ}C$, and showed anisotropic phases above $350^{\circ}C$, for 1 h of soaking time. The viscosity of the MCTPs increased with increase in their softening points.

2D continuum viscodamage-embedded discontinuity model with second order mid-point scheme

Do, Xuan Nam,Ibrahimbegovic, Adnan Techno-Press 2018 Coupled systems mechanics Vol.7 No.6

This paper deals with numerical modeling of dynamic failure phenomena in rate-sensitive brittle and/or ductile materials. To this end, a two-dimensional continuum viscodamage-embedded discontinuity model, which is based on our previous work (see Do et al. 2017), is developed. More specifically, the pre-peak nonlinear and rate-sensitive hardening response of the material behavior, representing the fracture-process zone creation, is described by a rate-dependent continuum damage model. Meanwhile, an embedded displacement discontinuity model is used to formulate the post-peak response, involving the macro-crack creation accompanied by exponential softening. The numerical implementation in the context of the finite element method exploiting the second-order mid-point scheme is discussed in detail. In order to show the performance of the model several numerical examples are included.

Preparation of petroleum-based binder pitch for manufacturing thermally conductive carbon molded body and comparison with commercial coal-based binder pitch

조정훈,임지선,김민일,이영석,배병철 한국탄소학회 2020 Carbon Letters Vol.30 No.4

In the present study, carbon molded bodies were prepared by using graphite/coke fllers and petroleum-based binder pitch with various softening points, and the thermal properties of the prepared carbon molded bodies were investigated. The ratio of a binder afects the molded body preparation: no molded body was prepared at a low binder pitch content, and swelling occurred during the thermal treatment at a high binder pitch content. The binder pitch thermal treatment yield was the high�est at 41 wt% at the softening point of 150 °C and the lowest at 23 wt% at the softening point of 78 °C. A signifcant mass reduction was found in the range of 150 to 300 °C in the petroleum-based binder pitch, and in the range of 300 to 475 °C in the coal-based binder pitch. The molecular weight of the binder pitch was analyzed through the matrix-assisted laser desorption/ionization time-of-fight (MALDI-TOF) method. The molecular weight ratio within the interval showing the highest binder pitch molecular weight (178 to 712 m/z) was the highest at 66.4% in the coal-based binder pitch (softening point 115 °C) and the lowest at 46.0% in the petroleum-based binder pitch (softening point 116 °C). When the petroleum�based binder pitch was applied, as the softening point was increased, the voids decreased and thus the thermal conductivity increased. The highest thermal conductivity was 99.5 W/mK for the carbon molded bodies prepared using the coal-based binder pitch and 102.8 W/mK for those prepared by using the petroleum-based binder pitch. The results showed that the thermal properties were similar between the coal-based binder pitch (softening point 115 °C) and the petroleum-based binder pitch (softening point 150 °C).

Modified oxidative thermal treatment for the preparation of isotropic pitch towards cost-competitive carbon fiber

Ko, Seunghyun,Choi, Jong-Eun,Lee, Chul Wee,Jeon, Young-Pyo THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2017 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.54 No.-

<P><B>Abstract</B></P> <P>A modified oxidative thermal treatment was developed to increase the softening point of a pitch precursor while minimizing the pitch yield loss. An O<SUB>2</SUB>/N<SUB>2</SUB> mixed gas was used as the reaction gas, and the softening point and pitch yield variations were measured at different O<SUB>2</SUB> concentrations. As a result, when softening point increased from 130 to 249°C, the pitch yield remained almost constant (only 0.6% drop). Structural analysis performed via MALDI-TOF, FTIR, and <SUP>1</SUP>H and <SUP>13</SUP>NMR showed that condensation reaction between pitch molecules in the presence of O<SUB>2</SUB>-containing gas followed a different mechanism depending on the O<SUB>2</SUB> concentration. In addition, the precursors were spun into pitch fibers and carbonized at 1100°C. During the spinning, they exhibited excellent spinnability without breakage for more than 10min of spinning. The obtained carbon fibers showed high tensile strengths comparable to that of a commercial isotropic-pitch-derived carbon fiber (0.83GPa). The current study showed that the modified thermal treatment is useful for the preparation of cost-competitive pitch precursors suitable for carbon fiber production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An O<SUB>2</SUB>/N<SUB>2</SUB> mixed gas was used as the reaction gas, and the softening point and pitch yield variations were measured at different O<SUB>2</SUB> concentrations. </LI> <LI> When softening point increased from 130 to 249°C, the pitch yield remained almost constant (only 0.6% drop). </LI> <LI> Pitches prepared by the modified oxidative thermal treatment exhibited excellent spinnability without breakage for more than 10min of spinning. </LI> <LI> The obtained carbon fibers showed high tensile strengths comparable to that of a commercial isotropic-pitch-derived carbon fiber (0.83GPa). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

폐비닐을 함유한 아스팔트 바인더 물성의 실내 시험

이강훈,김영진,정진훈,김병준,임진선 한국도로학회 2012 한국도로학회논문집 Vol.14 No.5

PURPOSES : In this study, various laboratory tests were performed to investigate the suitability of wasted vinyl as a modifier of asphalt binder. METHODS: Based on the ASTM specification, variations in material properties of asphalt binder such as penetration, flash point, softening point, ductility, penetration index (PI), and performance grade (PG) with vinyl content were tested and analyzed. RESULTS : Lavoratory tests revealed that penetration and ductility of the asphalt binder increased with the vinyl content. The flash point,softening point, and PI decreased, and PG changed from 64-22 to 70-22 with increase of the vinyl content. CONCLUSIONS: Wasted vinyl modified the material properties of the asphalt binder. However, the asphalt binder with vinyl content over 6.0% was unsuitable as a pavement material. PURPOSES : In this study, various laboratory tests were performed to investigate the suitability of wasted vinyl as a modifier of asphalt binder. METHODS: Based on the ASTM specification, variations in material properties of asphalt binder such as penetration, flash point, softening point, ductility, penetration index (PI), and performance grade (PG) with vinyl content were tested and analyzed. RESULTS : Lavoratory tests revealed that penetration and ductility of the asphalt binder increased with the vinyl content. The flash point,softening point, and PI decreased, and PG changed from 64-22 to 70-22 with increase of the vinyl content. CONCLUSIONS: Wasted vinyl modified the material properties of the asphalt binder. However, the asphalt binder with vinyl content over 6.0% was unsuitable as a pavement material.

Influence of softening point on electrochemical properties of pitch-based activated carbons

김경훈,정진영,정민정,이영석 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Pitches with different softening points (190, 220, 250, and 280°C) were reformed by heat treatment from PFO (pyrolized fuel oil) and directly activated with 6 M KOH at 800°C for 3 hr. In this study, the influence of softening point on textural and electrochemical properties of pitch-based activated carbon was investigated. The properties of pitch-based activated carbon were confirmed by FE-SEM (field emission scanning electron microscopy) and N₂ adsorption method at 77 K. Also the electrochemical properties of pitch based activated carbons were confirmed by cyclic-voltammetry in 1 M H₂SO₄.

Modified oxidative thermal treatment for the preparation of isotropic pitch towards cost-competitive carbon fiber

고승현,최종은,이철위,전영표 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

A modified oxidative thermal treatment was developed to increase the softening point of a pitch precursor while minimizing the pitch yield loss. An O2/N2 mixed gas was used as the reaction gas, and the softening point and pitch yield variations were measured at different O2 concentrations. As a result, when softening point increased from 130 to 249 C, the pitch yield remained almost constant (only 0.6% drop). Structural analysis performed via MALDI-TOF, FTIR, and 1H and 13NMR showed that condensation reaction between pitch molecules in the presence of O2-containing gas followed a different mechanism depending on the O2 concentration. In addition, the precursors were spun into pitch fibers and carbonized at 1100 C. During the spinning, they exhibited excellent spinnability without breakage for more than 10 min of spinning. The obtained carbon fibers showed high tensile strengths comparable to that of a commercial isotropic-pitch-derived carbon fiber (0.83 GPa). The current study showed that the modified thermal treatment is useful for the preparation of cost-competitive pitch precursors suitable for carbon fiber production.

Controlling the electrochemical properties of an anode prepared from pitch-based soft carbon for Li-ion batteries

Kim, B.H.,Kim, J.H.,Kim, J.G.,Im, J.S.,Lee, C.W.,Kim, S. THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2017 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.45 No.-

<P>A petroleum residue-based carbon electrode for use in a lithium-ion battery was prepared through the thermal reaction of pyrolyzed fuel oil. The samples were characterized by their softening point, crystallinity and battery performance. The softening point and pitch crystallinity increased with higher reaction temperatures and longer reaction times. The prepared pitch-based carbon had a 300-350 mAh/g capacity and 71-78% initial efficiency. Notably, the high-softening-point pitch resulted in the developed crystallinity through polymerization and condensation. In conclusion, the high-softening point pitch had a better initial efficiency and rate capability based on its high crystallinity. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.</P>

Controlling the electrochemical properties of an anode prepared from pitch-based soft carbon for Li-ion batteries

김백환,김지홍,김종구,임지선,이철위,김석 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

A petroleum residue-based carbon electrode for use in a lithium-ion battery was prepared through thethermal reaction of pyrolyzed fuel oil. The samples were characterized by their softening point,crystallinity and battery performance. The softening point and pitch crystallinity increased with higherreaction temperatures and longer reaction times. The prepared pitch-based carbon had a 300–350 mAh/g capacity and 71–78% initial efficiency. Notably, the high-softening-point pitch resulted in thedeveloped crystallinity through polymerization and condensation. In conclusion, the high-softeningpointpitch had a better initial efficiency and rate capability based on its high crystallinity.