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N2O供給により燃焼をON/OFF制御できる非自律燃焼性(非自燃性)固体推進薬の調製を試み，その燃焼性を調査した．本研究では，スプレードライにより防湿処理を施した硝酸アンモニウム(AN)と過塩素酸アンモニウム(AP)を酸化剤とし，末端水酸基ポリブタジエン(HTPB)をバインダとした固体推進薬を調製した．HTPBを23.5 wt%とし，酸化剤中のAN/AP比を40/60，50/50，60/40 とした推進薬についてN2雰囲気0.3-6.0 MPa で燃焼試験を行ったところ，AN/AP=40/60 はすべての圧力範囲で燃焼が完結したが，50/50 および60/40 では0.5-0.7 MPa 以下で着火しなかった．これら2 種類の推進薬は，N2O供給下，0.3 MPa での燃焼試験では燃焼が持続し，N2O供給を止めると燃焼が停止したため，本実験で調製したAN/AP 系推進薬はN2O供給により燃焼をON/OFF制御できる可能性が示唆された．, In this study, in an attempt to prepare propellants capable of on/off control of combustion by oxidizing gas supply, we prepared incombustible propellants in a N2 atmosphere composed of moisture-proof ammonium nitrate (AN) prepared by spray drying and ammonium perchlorate (AP) as oxidizers and hydroxyl-terminated polybutadiene (HTPB) as a fuel, and investigated their combustibility by N2O supply. The burning tests performed under a N2 atmosphere for the propellants having different AN/AP mass ratios (AN/AP = 40/60, 50/50, and 60/40) with 23.5 wt% HTPB revealed that the AN/AP=50/50 and 60/40 samples did not ignite under pressures less than 0.5-0.7 MPa, whereas the AN/AP=40/60 sample burned under the entire tested pressure range (0.3-6.0 MPa). Moreover, it was confirmed that the AN/AP=50/50 and 60/40 samples stably burned under N2O supply at 0.3 MPa. However, when the N2O supply was stopped, their combustion was interrupted with a little time delay, suggesting that combustion of the prepared propellants can be controlled by regulating the N2O supply., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1830031008, レポート番号: JAXA-RR-18-006

自動車エアバッグ用ガス発生剤の燃焼ガスに含まれる有害ガス(CO, NH3 およびNOx)を低減させるための基礎的研究として, 硝酸グアニジン(GN)/塩基性硝酸銅(BCN)混合物に対してストランド燃焼試験を行い, 燃焼速度および燃焼ガス組成に及ぼす試料組成および雰囲気ガス種類の影響について検討した. その結果, GN/BCN のモル比が7/4 の際に燃焼速度が最大となった. 一方, 同組成の試料は, 試験を実施したその他の試料(GN/BCN = 12/4, 10/4, 9/4, 8/4)の中で最も有害ガス発生量が多かった. また, N2, Ar およびHe 雰囲気下において燃焼試験を実施したところ, He 雰囲気下の圧力指数はその他の雰囲気に比べ高くなった. また, NOx の発生量は, Ar < N2 < He の順に増加する傾向が見られ, 雰囲気ガスの熱伝導率の違いが燃焼ガス組成に影響を及ぼした可能性がある., As a fundamental study for reducing toxic gases such as CO, NH3, and NOx in the combustion gas for gas generators in automotive airbags, the influence of composition ratio and type of atmospheric gas on the combustion behavior of a guanidine nitrate (GN) and basic copper nitrate (BCN) mixture was investigated using the chimney-type strand burner. The results indicated that the burning rate was highest at the molar ratio of GN/BCN = 7/4. However, the mixture with this molar ratio released the most amount of toxic gases among the other examined samples (GN/BCN = 12/4, 10/4, 9/4, 8/4). In addition, the results of combustion tests conducted under N2, Ar, or He atmospheres revealed that the pressure index under He was higher than that under the other atmospheres. And, the amount of NOx increased under the different atmospheres in the following order: Ar < N2 < He. This may indicate that the thermal conductivity of atmospheric gases influences the combustion gas composition., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1730012011, レポート番号: JAXA-RR-17-008

本研究では, 硝酸アンモニウム(AN), 過塩素酸アンモニウム(AP)およびポリマーが混合した粒子(粒径約34μm)をスプレードライにより造粒し, 同粒子を酸化剤とする推進薬を調製した。また, 推進薬調製時のスプレードライ粒子とパインダ(末端水酸基ポリプタジエン)との混合性および調製した推進薬の着火性について検討した。その結果, ポリマーに水溶性ポリマーを用いて調製したスプレードライ粒子は粒子表面が平滑であり, また, パインダと混合した際の粘度が低く混合性が高い傾向が見られた。また, 酸化剤(AN/AP)中のAN比を≤20wt.%とした推進薬は, 燃焼中断することなく燃焼が持続し, また, 市販のANおよびAPを酸化剤とする推進薬と比較して圧力指数が低下することが明らかになった。, In this study, we prepared solid propellants of spray dried particles (diameter: approx. 34μm) with mixed ammonium nitrate (AN), ammonium perchlorate (AP), and polymer. And we evaluated the viscosity of the mixtures of the spray dried particles and the binder (Hydroxyl-terminated polybutadiene) as an index of miscibility and the combustion characteristics of the prepared propellants. The spray dried particles of a water-soluble polymer easily mixed with HTPB, and the viscosity of the resulting mixture was low. This phenomenon was possibly related to the smooth surface of the particles, as observed by SEM. The results of the combustion test conducted under 3 MPa of pressurized condition show that the combustion of the prepared propellants with the AN mass ratio less than or equal to 20 wt.% (in AN/AP) was successfully completed without any misfiring. In addition, the pressure dependency of the burning rate was lower than that of the propellant prepared from commercial AN and AP., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1630043011, レポート番号: JAXA-RR-16-006

本研究ではAN/AP系推進薬に関する基礎研究として、スプレードライによりANおよびAPが一体化した粒子を調製し、SEMによる表面状態の観察およびTG-DTAによる熱分析を実施した。SEM観察の結果、ANの吸湿に由来する凝集が観察されたものの、概ね球状の粒子が観察された。平均粒子径は36-38μmであった。TG-DTA測定の結果では、重量減少を伴う吸熱が130-230 および280-375 C付近に観察され、280-375 C付近に発熱が観察された。ANおよびAP単独との比較から，吸熱ピークは、それぞれの熱分解に由来することが示唆された。一方、発熱ピークはANおよびAP単独では観察されず、AN/AP混合粒子のみで観察されることから、ANとAPの反応に由来すると考えられる。また、AN単独の場合、相転移に由来する吸熱ピークが43、 90 および 125 C付近に観察されるが、AN/AP混合粒子では、90 CのピークがANと比較して非常に小さくなる等、結晶構造の変化を示唆する結果が得られた。, In this study, we prepared ammonium nitrate (AN)/ ammonium perchlorate (AP) mixed particle using spray drying for the fundamental study on AN/AP-based propellants. We investigated their surface properties and thermal behavior by scanning electron microscopy (SEM) and thermogravimetry/differential thermal analysis (TG/DTA) respectively. In the result of SEM analysis, the shape of the AN/AP particles was almost spherical. In some cases, particle partially aggregated because of moisture absorption by AN. The average particle diameter was approximately 36-38 μm. In the result of TG/DTA, endothermic peaks were observed around 130-230 and 280-375 C and exothermic peak was observed around 230-280 C. From the comparison with the result of AN and AP, it is considered that endothermic peaks were caused by each thermal decomposition. On the other hand, we suggest that the exothermic peak may result from the reaction between AP and AN because it is only observed in the curves of AN/AP. Endothermic peaks derived from crystal structure transformation of AN were observed around 43, 90 and 125 C by thermal analysis of AN and AN/AP. The peak around 90 C of AN/AP was extremely smaller than that of AN, and this suggested that crystal structure of AN might be changed. Keywords: AN, AP, Spray drying, DSC, TG-DTA., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1530013003, レポート番号: JAXA-RR-14-005

硝酸アンモニウム(AN)は吸湿性を有し，室温近傍においても体積変化を伴う固相間相転移が起こるなど工業利用における課題を有する。我々の既往の研究では，これらの問題を解決するため，AN，相安定化剤である硝酸カリウム(PN)およびポリマー(例：PVA，CMC，Latex)が一体化した微粒子(AN/PN/Polymer)を調製し，ポリマーの効果により防湿性が向上することを明らかにした。本研究では，調製したAN/PN/Polymer 微粒子の相転移および熱分解挙動をDSC を用いて観察した。実験の結果，PN の効果により，室温-100 C の温度領域にAN 由来の相転移が観察されず，相安定化していることが確認された。また，PVA およびCMC にもAN に対する相安定化効果がある可能性が示唆された。AN/PN/Polymer の熱分解挙動を観察したところ，190-245 C および272-291 C に2 つの発熱ピークが観察された。低温側の発熱は，AN と融解あるいは熱分解したポリマーとの反応が関係している可能性があり，高温側の発熱はAN 自身の発熱分解に由来するものと推察した。, Ammonium nitrate (AN) has problematic properties for industrial application such as high hygroscopicity and crystal structure transformation accompanied by volumetric change. In our previous studies, we prepared spray-dried particles comprising three components: AN, potassium nitrate (PN) as a phase stabilizer, and polymers (e.g. PVA, CMC, Latex), which was confirmed to provide effective moisture proofing. In the present study, the crystal transformation behavior and the thermal decomposition behavior of AN/PN/Polymer particles were investigated by differential scanning calorimetry (DSC). The results showed that phase-stabilized AN could be successfully prepared by the addition of PN. In addition, an intriguing possibility was identified in that CMCA and PVA, which were both added as polymer components for moisture proofing, also acted as phase stabilizers for AN crystal transformation. When the thermal decomposition behavior was investigated, two exothermic peaks were observed at 190-245 C (first peak) and 272-291 C (second peak) in the result of AN/PN/Polymer. It is possible that the first peaks in the DSC curves for the AN/PN/polymer mixtures result from the reaction of AN with melted PVA, or decomposition products and gases derived from CMC and Latex, and the second peak is due to decomposition of AN on its own., 形態: 図版あり, Physical characteristics: Original contains illustrations, 資料番号: AA0062089003, レポート番号: JAXA-RR-13-009

Ammonium nitrate (AN) shows promise as a gas generator component because of its affordable price. However, handling this compound is problematic because it is highly hygroscopic and hence undergoes aggregation and solidification. In this study, in order to prevent the hygroscopicity of phase-stabilized ammonium nitrate (AN/KN), we prepared particles from a combination of AN/KN and a polymer (moisture-proof agent) by the spray drying technique and investigated the hygroscopicity. A white powder with a particle diameter of about 20-40microns was successfully prepared by spray drying water solutions (or water dispersions) containing AN/KN and each of the three types of polymers. The results of elemental analysis by Scanning Electron Microscope/Energy Dispersive X-ray spectrometry (SEM/EDX) indicated that each component was homogeneously distributed in the particles. Particle aggregation was hardly observed, and the moisture absorption amount was lower than that in the case of the polymer-free (blank) sample. Evn under high-moisture conditions, the particles did not deliquesce immediately and retained their original shape, unlike the blank sample., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA0061907004, レポート番号: JAXA-RR-12-005

平成24年度宇宙輸送シンポジウム (2013年1月17日-1月18日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)), 相模原市, 神奈川県, Space Transportation FY2012 (January 17-18, 2013. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, Translation title: The synthesis of phase stabilization and atomization of Ammonium Nitrate (AN) coated with moisture prevention using spray-dry process, 資料番号: AA0061856004, レポート番号: STCP-2012-004

平成23年度宇宙輸送シンポジウム（2012年1月19日-20日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)（ISAS)）, 相模原市, 神奈川県, Space Transportation Symposium FY2011 (January 19-20, 2012. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000003004, レポート番号: STCP-2011-004