에너지화 가소제는 고에너지 물질의 에너지 및 oxygen balance를 증가시킬 수 있는 특성으로 인하여 많은 관심을 가지게 되었다. 따라서, 이상적인 에너지화 가소제는 높은 에너지를 지녀야 하며, 낮은 기계적 감도, 고분자 매트릭스와의 높은 혼화성, 저온 및 고온 열 안정성, 넓은 온도 범위에서의 윤활성, 누출에 대한 높은 저항성 및 경제성을 지녀야 한다. 뿐 만 아니라, 공공의 건강 및 안전 규정을 준수해야만 한다. 수 많은 종류의 에너지화 가소제가 현재까지 개발되어 왔지만, 이들 개발된 에너지화 가소제들은 이러한 요구 조건들을 모두 충족하지는 못하는 실정이다. 본 연구에서는 dinitropropanediol, ethylene glycol 및 formaldehyde를 이용한 aldol condensation으로 새로운 에너지화 가소제인 bis(2,2-dinitropropyl ethylene) formal (BDNPEF)를 합성하였다. 본 합성과정에서 생성된 여러 가지 혼합물들 중에서 현재 에너지화 가소제로 적용되고 있는 bis(2,2-dinitropropyl) formal (BDNPF)가 부산물로 생성됨을 확인하였으며, 이를 성공적으로 분리하였다. 합성된 이들 신규 물질들은 핵자기공명 분석법, 원소분석 및 퓨리어 변환 적외선 분광법들을 이용하여 구조를 확인하였다. 합성된 에너지화 가소제들의 물리적 성질을 측정하였다. 신규 에너지화 가소제인 BDNPEF의 분자량은 386.27 g/mol, oxygen balance는 -70.42%, 밀도는 1.3724 g/ml (22 oC), 점도는 30 oC와 60 oC에서 각각 0.136 Pa·s와 0.052 Pa·s를 나타내었다. BDNPF의 경우는 312.2 g/mol의 분자량, -51.25%의 oxygen balance, 1.3492 g/ml의 밀도와 점도는 30 oC와 60 oC에서 각각 0.115 Pa·s와 0.042 Pa·s를 나타내었다. 이들의 분자량 및 oxygen balance값을 비교한 결과에 의하면, BDNPEF가 BDNPF에 비해 둔감 특성 및 가소화 효과가 높을 것으로 예측되었다. 또한, 열적 특성 평가 결과에 의하면, BDNPEF의 유리전이온도는 -66.54 oC 및 열분해 온도는 257.85 oC로 측정되었다. 반면에, BDNPF는 -69.48 oC의 유리전이온도와 259.64 oC의 열분해 온도를 나타내었다. 합성된 신규 가소제인 BDNPEF와 GAP polyol prepolymer을 중량비로 50/50으로 혼합하여 점도를 측정하여 점도 감소비를 이용하여 가소화 효과를 측정하였다. 그리고, 기존의 상용 에너지화 가소제들과 함께 실험을 하여 가소화 효과를 상호 비교하였다. 30 oC 온도 조건에서, GAP polyol prepolymer의 점도는 6.105 Pa·s 였으나, BDNPEF/GAP polyol (50/50 w/w)의 조성의 경우, 점도가 1.090 Pa·s로 현저히 감소하였다. BDNPF를 적용한 경우에도 BDNPF/GAP polyol (50/50 w/w)의 조성의 경우, 점도가 0.991 Pa·s로 감소하였다. 그리고, 현재 사용되고 있는 상용 에너지화 가소제들의 점도 감소 결과와 비교해도 비슷한 결과를 나타내었다. 따라서, 이들 가소화 결과로부터, 합성된 에너지화 가소제인 BDNPEF는 새로운 에너지화 가소제로서의 사용 가능성을 확인해 주고 있다.
Energetic plasticizers have aroused great interest since they can enhance energy and oxygen balance of the compositions to which they are added. Ideal energetic plasticizers should be highly energetic, lowly sensitive, highly compatible with polymers, stable in both high and low temperature environments, sufficiently lubricating over a wide temperature range, leaching and migration resistant, and inexpensive. They should fulfill health and safety regulations. No existing energetic plasticizers can achieve the ideal requirements at present, though a lot of energetic plasticizers have been discovered so far. To discover a preferable new energetic plasticizer, bis(2,2-dinitropropyl ethylene) formal (BDNPEF), has been designed and synthesized in this research. The main chain of BDNPEF is similar to ether oligomer, which is designed for being well compatible with polyether polymer binders. BDNPEF is synthesized by the reaction of 2,2-dinitropropanol (DNP-OH), ethylene glycol (EG) and formaldehyde with the catalyst, boron trifluoride diethyletherate (BF3·OEt2). The formation processes of BDNPEF and side products are presented in Chapter 3-1. There are four kinds of side products produced during the reaction. Therefore, the purification process of BDNPEF is highly technical. It is very fortunate that one of the side products is bis(2,2-dinitropropyl) formal (BDNPF), which is a well known, excellent and widely used energetic plasticizer. The molecular structures of BDNPEF and BDNPF are exhaustively confirmed by means of nuclear magnetic resonance (NMR) spectrometer, elemental analyzer and fourier-transform infrared (FT-IR) spectroscopy. Results of the characterizations of BDNPEF and BDNPF are discussed in Chapter 3-2. They are in good agreement with the expected data. Thus, BDNPEF is successfully synthesized by means of the methodology used. To evaluate the properties of BDNPEF, decomposition temperature (Td), glass transition temperature (Tg), viscosity and density are measured. Decomposition temperature and glass transition temperature of BDNPEF are measured by differential scanning calorimetry (DSC). Decomposition temperature is also confirmed by thermogravimetric analysis (TGA). Viscosity is measured by rheometer apparatus. Density is measured by a micro balance and a precision syringe. The results are discussed in Chapter 3-3 and Chapter 3-4. Chapter 3-3 presents physical properties of BDNPEF and BDNPF. And Chapter 3-4 presents thermal properties of BDNPEF and BDNPF. Molecular weight of BDNPEF was 386.27 g/mol and its oxygen balance (OB) was -70.42%. Molecular weight of BDNPF was 312.20 g/mol. OB of BDNPF was -51.25%. OB of BDNPEF was more negative. Therefore, BDNPEF was less sensitive than BDNPF. BDNPEF possesses one more ethylene and methylene unit than BDNPF. Therefore, chemical structure of BDNPEF is more similar than BDNPF's to that of polyether oligomer. Thus, BDNPEF can afford a better plasticization effect than BDNPF in polyether polymers. Besides, molecular weights of plasticizers between 400-1,000 g/mol were considered to give optimum plasticization effect. Thus, BDNPEF has the chance to afford optimum plasticization effect. Viscosity of BDNPEF is 0.136 Pa·s at 30 oC and 0.052 Pa·s at 60 oC. Viscosity of BDNPF is 0.115 Pa·s at 30 oC and 0.0423 Pa·s at 60 oC. Decomposition temperature of BDNPEF is 257.85 oC (TGA) (Td (BDNPF) = 259.64 oC) and glass transition temperature of it is -66.54 oC (Tg (BDNPF) = -69.48 oC). Glass transition temperature of GAP is -48.8 oC. Therefore, the addition of BDNPEF in GAP polyol had the effect of increasing the chain mobility of GAP polyol. From these data, it can be suggested that BDNPEF can be used as an energetic plasticizer for energetic binders as BDNPF. Chapter 3-5 evaluates the capability of BDNPEF of lowering glass transition temperature and viscosity of GAP polyol comparing with the other familiar energetic plasticizers. The results show that BDNPEF has more splendid ability of lowering glass transition temperature and viscosity of GAP polyol than BDNPF/BDNPA, which is considered to be an excellent energetic plasticizer. Therefore, BDNPEF can be used as a potential energetic plasticizer for particular application in energetic binders.