• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.147-153
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• 1997

Bismaleimides(BISMI) containing ester linkages were prepared by the chlorinated N-(p-carboxyphenyl)maleimide and N-(p-hydroxyphenyl)maleimide. The photosensitive properties of BISMI were investigated via changes of the irradiation time. Benzil dimethyl ketal was used as a photoinitiator. The effect of photoinitiator onto BISMI increase in average as increasing photoinitiator concentration and irradiation time. The yield of residual film and image pattern and resolution also measured and discussed.

• Journal of the Korean Chemical Society
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• v.14 no.3
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• pp.201-206
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• 1970

Furfuryl acetate was chlorinated in presence of acetic acid using carbontetrachloride as the solvent. When the chlorination proceeded at the low concentration of acetic acid, the formation of the tetrachloride was more efficient than that of higher concentration. The chlorination done in presence of various Lewis acids such as aluminum chloride, hydrogen fluoride, and borontrifluoride could not give high yield of tetrachloride, but trichloride. In case of borontrifluoride and hydrogen fluoride, the decomposition of the reaction mixture was apparent. The results were discussed in terms of the stability of furfuryl nucleus towards an electron acceptor and the convenient procedure of preparing trichloro furfuryl acetate was described.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.211-221
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• 2016

Waste salt generated from a pyro-processing for the recovery of uranium and transuranic elements has high volatility at vitrification temperature and low compatibility in conventional waste glasses. For this reason, KAERI (Korea Atomic Energy Research Institute) suggested a new method to de-chlorinate waste salt by using an inorganic composite named SAP ($SiO_2-Al_2O_3-P_2O_5$). In this study, the de-chlorination behavior of waste salt and the microstructure of consolidated form were examined by adding $B_2O_3$ and $Fe_2O_3$ to the original SAP composition. De-chlorination behavior of metal chloride waste was slightly changed with given compositions, compared with that of original SAP. In the consolidated forms, the phase separation between Si-rich phase and P-rich phase decreases with the amount of $Al_2O_3$ or $B_2O_3$ as a connecting agent between Si and P-rich phase. The results of PCT (Product Consistency Test) indicated that the leach-resistance of consolidated forms out of reference composition was lowered, even though the leach-resistance was higher than that of EA (Environmental Assessment) glass. From these results, it could be inferred that the change in the content of Al or B in U-SAP affected the microstructure and leach-resistance of consolidated form. Further studies related with correlation between composition and characteristics of wasteform are required for a better understanding.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.157-166
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• 2017

In general, carbonation and chlorine ions are the most harmful causes of deterioration of concrete structures. Recently, a method has been developed to control the corrosion of rebar in concrete containing chloride by impregnating a Surface coating material with a inhibitor. In this study, accelerated carbonation and differential thermogravimetric analysis (TG-DTA) and CASS tests were carried out to evaluate the characteristics of Surface coatings containing Organic Corrosion inhibitors which are excellent in corrosion inhibition and fix degradation causes $CO_2$ and $Cl^-$. As a result of the experiment, TG-DTA analysis and accelerated carbonation showed that $CO_2$ was directly reacted with amine derivative in concrete by the incorporation of Organic Corrosion inhibitor. In other words, $CO_2$ was immobilized and carbonation inhibition effect was confirmed. In addition, in the CASS test, the specimen coated with the Surface coating material containing the Organic Corrosion inhibitor with $Cl^-$ fixing property showed no corrosion until the 28th day and had excellent performance in preventing corrosion of a rebar by the chloride ion.

• Journal of the Korean Chemical Society
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• v.43 no.6
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• pp.670-675
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• 1999

6-[1-(4-Ribitylanilino)ethyl]-1,3,7-trimethyllumazine (2), which is related to pteridine moiety of methanopterin, was synthesized. 4-Ribitylaniline derivative was prepared from D-ribose and N-benzoyl-4-bromoaniline (7) as the starting materials through several steps. 6-Acetyl-1,3,7-trimethyllumazine (4) was obtained from the reaction of 4-amino-1,3-dimethyI-5-nitrosouracil (3) with 2,4-pentanedione by Timmis reaction. Compound 4 was converted to 6-(1-chloroethyl)-1,3,7-trimethyllumazin (6) by the reduction with sodium borohydride and followed by chlorination with thionyl chloride. The nucleophilic displacement reaction of compound 6 with 4-(2,3:4,5-di-O-iso-propylidene-D-ribityl)aniline (13) in anhydrous DMF yielded 6-[1-{4-(2,3:4,5-di-O-isopropylidene-D-ribityl)anilino}ethyl]-1,3,7-trimethyllumazine (14). The target molecule 2 was obtained by the hydrolysis of compound 14 in the presence of an acid catalyst.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.169-177
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• 2006

In this study, it was studied that the removal rate of VOC by the catalytic combustion. The combustion temperature was changed by the contact type of VOC(space velocity and catalyst depth) and the space velocity(SV) was defined by the rate of gas volume flow rate(Q, $m^3/hr$) over volume(V, $m^3$) of catalyst (SV=Q/V). The space velocity of catalytic combustor is maintained $10,000{\sim}50,000hr^{-1}$. it was studied that the conversion rate of VOC by the catalytic combustion. The combustion temperature was changed by the contact type of VOC and catalyst and the space velocity was defined by the rate of gas volume flow rate over volume of catalyst. The VOC which pass thru the heat exchanger was measured by the hydro ionic detector and measured the VOC removal rate by the activated catalyst in the reaction temperature range of 373K-423K. The removal rate was measured over 100 times. In the automobile painting booth The VOC concentration was 63.37ppm and the removal rate was 70 % at 373K and 78.92% at 423K. The removal rate was increased as increased the temperature.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.191-196
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• 2001

${\alpha},{\beta}$-Unsaturated carboxanilides 5 with trifluromethylated dihydro-1,4-oxathiins were synthesized for the development of new agrochemical fungicide. Chlorination of trifluoromethylated ${\beta}-keto$ ester 6 followed by the reaction with 1,2-mercaptoethanol gave intermediate 1,4-oxathiane 11. Without purification of 11, substitution of hydroxy group by chlorine, followed by dehydrochlorination of 10 in the presence of triethylamine afforded trifluoromethylated dihydro-1,4-oxathiin ethyl ester 9. Acylation of the hydroxy group of the carboxylic acid 12 followed by treatment of various amines gave the corresponding trifluoromethylated dihydro-1,4-oxathiin carboxamides 5. Antifungal screening (in vivo) of the synthesized compounds against typical plant diseases, which include rice blast, rice sheath blight, cucumber gray mold, tomato late blight, wheat leaf rust, and barley powdery mildew, was carried out. Where meta position of the phenyl group was substituted with isopropoxy or isopropyl group, excellent antifungal activities against rice sheath blight and wheat leaf rust were detected.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.429-432
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• 2011

The feasibility of applications of the char obtained from a gasification process of municipal-waste refuse derived fuel (RDF) as an auxiliary fuel was evaluated by combustion experiments. The higher heating value of the RDF char was 3000~4000 kcal/kg and its chlorine content was below the standard requirement demonstrating its potential as an auxiliary fuel. In the combustion exhaust gas, the maximum $NO_x$ and $SO_2$ concentrations were 240 ppm and 223 ppm, respectively. If an aftertreatment is applied, it is possible to control their concentrations low enough to meet the air pollutant emission standard. The HCl concentration was relatively high indicating that a care should be taken for HCl emission from the combustion of RDF. Based on the temperature distribution within the reactor, the concentration change of $O_2$ and $CO_2$, and the amount and the loss on ignition of solid residue, it was inferred that the combustion reaction was the most reliable when the excess air ratio of 1.3 was used.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.3-4
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• 1999

최근 산업이 고속도화, 고능률화 및 고정멸화의 추세로 발전함에 따라 우수한 내마모성, 인성, 고온 안정성 및 내구성을 갖는 공구 및 금형을 요구하게 되었다. 그러나 이와같은 성질들은 어떤 단일 재료에서는 얻을 수 없으며 적당한 기판공구나 금혈위에 내마모성 보호피막을 coating함으로 비교적 저렴하게 얻을 수 있다. 화학증착법으로 TiC, TiN등을 증착시킬때에는 $1000^{\circ}C$정도의 반응온도가 필요하며 이러한 증착온도는 모재가 초경합금일때는 문제가 안되나 강재일 경우 모재의 연화와 칫수변화의 문제를 야기시킨다. 최근에는 플라즈마를 사용하여 증착반응온도를 $550^{\circ}C$ 이하로 낮추는 플라즈마 화학 증착볍(PACVD)이 대두되고 있다. 그러나 이 방법어서 는 뚱착하려는 금속원소가 TiCl4의 형태로 공급되고 있으므로 생성된 층이 염소를 포함하고 있다. 이 층에 잔존하는 염소는 층의 기계적 성질을 저하시키고 층내의 stress를 유발시킨다. 또한 HCI개스의 생성으로 인하여 펌프 및 장비의 부식이 촉진 된다 이러한 결점을 극복하기 위하여 금속유기화합물 전구체(metallo-organic precursor)로 $TiCl_4$를 대체하고자 하는 연구가 활발하게 진행되고 있으며 본 연구실에서 이에 대하여 연구한 결과를 소개하고자 한다. diethylamino titanium을 전구체로 사용하여 $H_2,\;N_2,\;Ar$분위기하에서 pulsed d.c.를 사용하는 MO-PACVD에 의하여 $150~250^{\circ}C$의 저온에서 Al 2024 기판에 TiCN층 형 성을 하였다. 전구체 증발온도는 $74~78^{\circ}C$의 온도범위어야 하며 고경도의 코탱층은 54% duty, 14.2kHz, 450V의 조건에서 얻어졌으며 duty, 주파수, 전압이 증가함에 따라 경도는 저하되었다. 이때의 표면 morphology를 SEM으로 조사한바 dome structure가 크게 발달되었음을 알 수 있었다. 본 실험의 온도 범위내에서 얻은 TiCN 증착반응의 활성화에너지는 7.5Kcal/mol이었다. 증착된 TiCN층은 우수한 내마모섣을 나타내었으며 스크래치테스트 결과 17N의 엄계하중을 나타내었다. 본 연구에서 변화 시킨 duty, 주파수, 전압의 범위에서는 층의 밀착력은 크게 변화하지 않았다. titanium isopropoxide를 전구체로 사용하여 Hz, Nz 분위기하에서 d.c.를 사용하는 MO-PACVD에 의하여 Ti(NCO) 코팅층을 SKDll, SKD61, SKH9 공구강에 형성시키는 공정을 개발하였다. 최적의 Ti(NCO) 코탱층을 얻기 위해 유입전구체 부피%의 양은 향착압력의 5%를 넘지 않아야 되고 수소와 젤소 가스비가 1:1일 때 가장 높은 코팅층의 경도값을 나타내었다. 수소와 질소 가스비가 3:7일 때 TiFeCr(NCO)의 복화합물 코팅층이 형성됨을 알 수 있었고 500t의 증착온도에서 얻은 Ti(NCO) 코팅층이 높은 경도값과 좋은 내식성을 나타내었다. 또한 이와같은 Ti(NCO) 코팅공정과 본 실험실에서 개발한 확산층만 형성시키는 plsma nitriding 공정을 결합하여 복합코탱층을 형성하였는데 이 복합코팅층은 고경도와 우수한 내마모성, 내식성 뿐만 아니라 10)N 이상의 뛰어난 밀착력을 나타내었다. 현재 많이 사용되고 있는 PVD법은 step coverage가 좋지 않은 점과 cost intensive p process라는 단점이 있다. MO-PACVD법은 이러한 문제를 해결할 수 있는 방법으로서 앞으로 지속적인 도전이 요구되는 분야이다.

• Resources Recycling
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• v.26 no.4
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• pp.88-94
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• 2017

The recovery of gold in cyclone type electrolytic cell was conducted from solution for stripping gold of PCB by cyanide. The electrolytic recovery behaviors of gold was investigated by reaction time and addition of electrolytic sodium hypochlorite (NaOCl) and gold plating additive (KG-120). Because the electrolysis generated NaOCl reacted with the cyanide in the leachate by alkaline chlorination, more than 99% of the cyanide was removed at a $NaOCl(g)/CN^-(g)$ ratio of 1.0. When NaOCl was added during the recovery of the gold from cyanide leachate in the cyclone electrolytic cell, the recovery of gold was 98% at the ratio of $NaOCl(g)/CN^-(g)$ from 0.5 to 2.5 in 480 minutes and decreased rapidly over the ratio of 3.0. Gold was recovered more than 99% by adding 1.5 and 4.5%(v/v) of KG-120 with NaOCl in 480 minutes. In particular, when the concentration of KG-120 was 3.5 and 4.5%(v/v), more than 96% of gold was recovered within 240 minutes and the initial recovery rate was relatively faster. The optimum concentration of KG-120 is 3.5%(v/v) considering the economic feasibility and efficiency.