Synthesis and its application of CO₂-soluble amino acid-based surfactants

권윤자,김학원 한국공업화학회 2006 한국공업화학회 연구논문 초록집 Vol.2006 No.1

유기염 고체산화제 Guanidine Dinitramide의 합성연구

김우람,권윤자,조영민,정선태 한국유화학회 2014 한국응용과학기술학회지 Vol.31 No.3

Dinitramide(N(NO2)2)염 화합물은 현재 고체 산화제로 로켓추진제의 중요한 원료 물질 중 하나이며, 환경 및 인체에 독성이 적은 친환경 에너지물질로 알려져 군사적 목적 외에 다양한 가스발생 제로서 사용되고 있다. 특히 무기염이 아닌 유기염인 Guanidine 염(GDN)은 수분에 대한 안정성이 향 상되어 안정적 보관 및 제조가 가능하므로 고순도 물질의 대량 생산이 가능하다. GDN의 출발물질로 guanidine의 음이온 염인 acetate, chloride, carbonate, nitrate, sulfate를 사용하여, GDN(GDN-1,2,3,4,5)을 최대 99%의 수율로 합성하였고, 이들의 물성을 다양한 분석기기를 이용하여 평가하였다. 흡수파장은 3452, 3402, 3354, 3278, 3208, 1642, 1570, 1492, 1416, 1337, 1179, 1000 cm-1이 공통적으로 관찰되었으며, 열적 특성 변화는 130 ℃에서 일어나기 시작하며 150℃~160 ℃에서 는 발열반응과 함께 물질의 변화가 관찰되었다. Dinitramide (N(NO2)2) salts are one of plausible oxidizing agents for a high efficient propellant. Guanidine dinitramide (GDN) is an organic salt improving its stability against moisture, so that enables massive production and long term storage. Several types of GDN (GDN-1,2,3,4,5) were synthesized using some types of starting materials such as guanidine acetate, chloride, carbonate, nitrate and sulfate. As a result of the experimental work, synthesized GDN from the carbonate salt appeared fairly pure relatively higher yield (99%) than the other samples. The absorption wave length of all prepared GDNs by FTIR were found at 3452, 3402, 3354, 3278, 3208, 1642, 1570, 1492, 1416, 1337, 1179 and 1000 cm-1. DSC analysis found a thermal phase change at 130℃, and indicated exothermic reaction at about 150℃ to 160℃.

Preparation and characterization of ADN based monopropellant

김우람,권윤자,조영민 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

A newly popular solid oxidizer ADN [ammonium dinitramide, NH4N(NO2)2] was synthesized from direct nutralization of sulfuric acid/nitric acid and potassium sulfamate. A liquid monopropellant composed of ADN and other addtives including simple molecular fuel was then prepared and characterized focusing on thermal properties. The monopropellant for an attitude control thruster of satellite projectiles should achieve high performance in exothermic decomposition or combustion reactions in the absence of external oxygen. This work utilized pure water for main solvent, which is safe in handling and easy in controlling the catalytic decomposition. The obtained basic properties of the test sample were 1.25~1.40 g/㎤ for true density, below 170℃ for decomposition temperature, and -30℃ for frozen point. The calorimetric values of the monopropellant was 466.73 J/g.

Preparation and characterization of ADN based environmentally friendly mono-propellants

김우람,권윤자,정동원,조영민 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Hydrazine [N₂H₄] is a widely used mono-propellant for spacecraft thrusters. The toxicity and handling problems, however, limit its utilization in the other fields. A newly popular solid oxidizer ADN [ammonium dinitramide, NH₄N(NO₂)₂] was synthesized from direct neutralization of sulfuric acid/nitric acid and potassium sulfamate. A mono-propellant composed of ADN and other additives including simple molecular fuel was then prepared and characterized focusing on thermal properties. The mono-propellant for an attitude control thruster of satellite projectiles should achieve high performance in exothermic decomposition or combustion reactions in the absence of external oxygen. This work utilized pure water for main solvent, which is safe in handling and easy in controlling the catalytic decomposition. The obtained basic properties of the test sample were 1.25~1.40 g/㎤ for true density, below 170°C for decomposition temperature, and -30°C for freezing point.

Comparative evaluation of purity of green energetic material (ammonium dinitramide) depending on refining method

김우람,권윤자,황성윤,조영민 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.6

Although the solid propellant, ammonium dinitramide (ADN, NH4N(NO2)2) is safe and thermally stable, it requires high purity for practical commercial applications. Even a small amount of impurities in ADN can create negative effects, including catalyst poisoning and thruster nozzle cloggings when it is used as a liquid propellant. Thus, we explored several purification processes for the precipitated ADN particles, such as repetition extraction, adsorption by activated carbons, and low-temperature extraction. These purifying methods help to improve the chemical purity as evaluated by FTIR, UV-vis, DSC, and IC analyses. Among the purification processes, adsorption was found to be the best method, showing a final purity of 99.768% based on relative quantification by ion chromatography.

Synthesis and characterization of a new energy material: Pyridinium dinitramide (Py-DN)

김우람,권윤자,Adedeji A. Adelodun,조영민 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

A solid oxidizer pyridinium dinitramide (Py-DN) has been newly synthesized as a low toxic chlorine-free energetic oxidizer. The reaction yield increased by 10% higher than the other dinitramide such as ADN because Py-DN was directly converted without sequential precipitation of intermediates. A thermal analyzer, a UV–visible spectrometer and a Fourier transform-infra-red spectrometer were used to characterize the physical and chemical properties of the synthesized Py-DN, and the results were compared with previously prepared salts of ammonium dinitramide (ADN, NH4N(NO2)2) and guanidine dinitramide [GDN, NH2C(NH2)NH2N(NO2)2]. The characteristic endothermic and exothermic decomposition temperatures of Py-DN were 77.4 C and 144.7 C, respectively, and the material had a combustion caloric value of 1,739 J/g. These low values indicate that Py-DN is more thermally sensitive than the conventional dinitramides. Furthermore, it enables to decrease the decomposition temperature, which can reduce preheating temperature required for thruster operation.

Dinitramide 계열 액상추진제 제조 및 특성 연구

김우람,권윤자,조영민 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

A monopropellant based on ammonium dinitramide(ADN), as a composite rocket propellant which provides simple handling with safety, has been prepared and characterized. In order to achieve its high purity, this work attempted multi stages’ adsorption in a lab scale. The starting material, ammonium dinitramide(ADN), was made through direct synthesis, and combined with a few test fuels such as C3H6O, C2H6O, CH3OH, NH4OH respectively. Thermal analysis of the prepared monopropellant showed a sharp exothermic peak with different onset temperatures (165~170°C) from mixtures.

1P-678 Preparation liquid propellants by dinitramide based oxidizers

김우람,박연수,권윤자,조영민 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

인공위성 자세 제어용으로서 적합한 비추력과 밀도 비추력을 갖춘 액상추진제를 고에너지산화제인 ADN[ammonium dinitramide], GDN[guanidine dinitramide], Py-DN[pyridinium dinitramide] 을 기반으로 각각 시험제조하였다. 추진제는 연료와 산화제, 용매와 상안정제 등을 혼합하여 제조하였고, 상안정성(DSC, freezing point), 밀도(ρ) 및 비추력(Isp)을 관찰하였다. 주 연료는 메탄올을 적용하되 에탄올과 혼합하여 발열량을 조절하였으며, 용매 내에서의 분산을 돕기 위하여 수산화아민을 비롯한 유기첨가물을 여러가지 비율로 첨가해보았다. 각 시료의 열분해 온도는 산화제 종류에 따라 168°C에서 182°C로 분포하였고, ADN 기반의 KHU-22 시료가 가장 높은 열분해 온도를 보여줌으로써 열안정성이 상대적으로 우수하다고 판단할 수 있었다. 각 시료의 비추력은 210 - 240 sec 로 나타났는 바, 기존의 상용 제품과 유사한 성능을 보유하고 있는 것으로 평가되었다. 한편, guanidine carbonate와 pyridine hydrochloride를 모체로 두 개의 질산기를 결합시킨 GDN과 Py-DN은 보조 추진제로서 액체연료의 발열량을 제어할 수 있는 조합으로의 개발여지가 충분하다.

Reaction conditions of wet synthesis of aluminium hydride

박미정,김우람,권윤자,조영민 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.1

새로운 Morindaparvin A 유도체들의 합성 (Ⅱ)

박시호,로영쇠,권윤자,강흔수,조인호,Park, Si Ho,Rho, Young S.,Kwon, Yoon Ja,Kang, Heun Soo,Cho, In Ho 대한화학회 1995 대한화학회지 Vol.39 No.3

이미 합성하여 보고한 1,2-Dihydroxyanthraquinone 유도체(9, 10)에 매우 간편하고 효율적인 방법으로 $-N(CH_3)_2,\;-OMe,\;-NH_2,\;-COOH,\;-CHClC(O)NH_2,\;-CHClCH_2OH,\;-CHClC(O)CH_3$ 등이 붙은 여러 종류의 새로운 Morindaparvin A(2~8)의 유도체를 합성하였다. A simple and efficient synthesis of new kind of Morindaparvin A derivatives (2~8) containing $-N(CH_3)_2,\;-OMe,\;-NH_2,\;-COOH,\;-CHClC(O)NH_2,\;-CHClCH_2OH\;and\;-CHClC(O)CH_3$ was completed with the reported 1,2-dihydroxyanthraquinone derivatives (9, 10).