Modification of Hydroxyl-terminated Polyether Binder by Liquid Fluororubber and Its Effect on Thermal Oxidation Behavior ofAluminum Powder

doi:10.12382/bgxb.2021.0184

Abstract

Abstract: The combustion of aluminum powder promoted by fluoride is a hot spot in the field of energetic materials in recent years. Hydroxyl terminated liquid fluororubber with high fluorine content is selected as fluorine source，which is introduced into hydroxyl-terminated polyether (HTPE) adhesive system to prepare modified HTPE films with different fluorine rubber contents.The morphology，mechanical properties，thermal stability and oxidizability of the modified HTPE films were tested and analyzed. The results show that the mechanical properties of the film decrease first and then increase with the increase in fluororubber content. The tensile strength and elongation at break of the film with fluororubber content of 50 wt% are 2.51 MPa and 217%，respectively. Compared with the unmodified HTPE film，its tensile strength is increased by 83%，and its elongation at break is decreased by 17%. Liquid fluororubber promotes the decomposition of HTPE polyurethane adhesive，and the initial decomposition temperature shifts from 263 ℃ to 209 ℃. The fluorine-containing oxidizing gas decomposed by the modified adhesive reacts with the alumina shell of aluminum powder to form AlF₃，which promotes the release of internal active aluminum core.

Key words: hydroxyl-terminatedpolyether, liquidfluororubber, aluminumpowder, thermalstability, oxidizability

CLC Number:

TJ450.4

SHEN Chen, YAN Shi, YAO Jie, JIAO Qingjie, LIAO Mingyi, CHANG Yunfei. Modification of Hydroxyl-terminated Polyether Binder by Liquid Fluororubber and Its Effect on Thermal Oxidation Behavior ofAluminum Powder[J]. Acta Armamentarii, 2022, 43(4): 780-787.

References

［1］ GRIEGO C，YILMAZ N，ATMANLI A.Analysis of aluminum particle combustion in a downward burning solid rocket propellant[J].Fuel，2019，327:405-412.
[2］ ZHOU Y N，LIU J Z，LI H P，et al.Combustion of aluminum
particles in a high-temperature furnace under various O₂/CO₂/H₂O atmospheres[J]. Journal of Thermal Analysis and Calorimetry，2020，139(1):251-260.
[3］ KONG C D，YU D，YAO Q，et al.Morphological changes of nano-Al agglomerates during reaction and its effect on combustion[J].Combustion and Flame，2016，165:11-20.
[4］ MAGGI F，DOSSI S，DELUCA L T.Combustion of metal agglomerates in a solid rocket core flow[J].Acta Astronautica，2013，92(2):163-171.
[5］ RASHKOVSKII S A.Statistical simulation of aluminum agglomeration during combustion of heterogeneous condensed mixtures[J].Combustion，Explosion，and Shock Waves，2005，41(2): 174-184.
[6］白帆，刘彦，黄风雷.带有铝粉反应的含铝炸药状态方程的研究[J].兵工学报，2017，38(增刊1):187-193.
BAI F，LIU Y，HUANG F L.Research on equation of state of detonation product of RDX-based aluminized explosive with aluminum reaction[J].Acta Armamentarii，2017，38(S1):187-193.(in Chinese)
[7］唐伟强，杨荣杰，李建民，等.高铝固体推进剂中氟化物促进铝燃烧研究进展[J].固体火箭技术，2020，43(6):679-686.
TANG W Q，YANG R J，LI J M，et al.Research progress of fluorides in high aluminum solid propellant to promote aluminum combustion[J].Journal of Solid Rocket Technology，2020，43(6):679-686. (in Chinese)
[8］ SIPPEL T R，SON S F，GROVEN L J.Altering reactivity of aluminum with selective inclusion of polytetrafluoroethylene through mechanical activation[J].Propellants，Explosives，Pyrotechnics，2013，38(2):286-295.
[9］ WANG H Y，REHWOLDT M，KLINE D J，et al.Comparison study of the ignition and combustion characteristics of directly-written Al/PVDF，Al/Viton and Al/THV composites[J].Combustion and Flame，2019，201:181-186.
[10］ REHWOLDT M C，WANG H Y，KLINE D J，et al.Ignition and combustion analysis of direct write fabricated aluminum/metal oxide/PVDF films[J].Combustion and Flame，2020，211:260-269.
[11］杭思羽，徐闻婷，韩志伟，等.铝-氟聚物含能亚稳态复合材料研究进展[J]. 材料导报，2019，33(增刊2):410-414.
HANG S Y，XU W T，HAN Z W，et al.Research progress on reaction mechanism of aluminum-fluoropolymer energetic metastable intermixed coomposites[J].Materials Reports，2019，33(S2):410-414.(in Chinese)
[12］ ZHOU X Y，GONG L，HUAN G F L，et al.Mechanism of the organic fluoride effect on the formation of agglomerates and condensed products in the combustion of aluminised solid propellants[J].Combustion Theory and Modelling，2020，24(1):1649727.
[13］闫涛，任慧，马爱娥，等.氟橡胶包覆层对纳米铝粉性能的影响研究[J].兵工学报，2019，40(8):1611-1617.
YAN T，REN H，MA A E，et al.Effect of fluororubber coating on the properties of nano-aluminum powders[J].Acta Armamentarii，2019，40(8):1611-1617. (in Chinese)
[14］王维伦，李建民，杨荣杰，等.含氟有机添加剂对含铝聚醚推进剂燃烧凝聚相产物的影响[J].兵工学报，2017，38(4):704-710.
WANG W L，LI J M，YANG R J，et al.Influence of organic fluorine-contained additives on condensed combustion products of aluminized polyether propellants[J].Acta Armamentarii，2017，38(4):704-710.(in Chinese)
[15］ AO W，LIU P J，LIU H，et al.Tuning the agglomeration and combustion characteristics of aluminized propellants via a new functionalized fluoropolymer[J].Chemical Engineering Journal，2020，382:122987.
[16］ GUO Y P，LI J M，GONG L，et al.Effect of organic fluoride on combustion performance of HTPB propellants with different aluminum content[J].Combustion Science and Technology，2021，193(4):702-715.
[17］ WAN F J，JIANG X J，ZHANG L，et al.Design and fabrication of energetic superlattice like-PTFE/Al with superior performance and application in functional micro-initiator[J].Nano Energy，2015，12:597-605.
[18］ OU Y P，SUN Y L，GUO X Y，et al.Investigation on the thermal decomposition of hydroxyl terminated polyether based polyurethanes with inert and energetic plasticizers by DSC-TG-MS-FTIR[J].Journal of Analytical and Applied Pyrolysis，2018，132: 94-101.
[19］ YUAN S，JIANG S K，LUO Y J.Cross-linking network structures and mechanical properties of novel HTPE/PCL binder for solid propellant[J].Polymer Bulletin，2020，78: 313-334.
[20］ CARO R.Hydroxy-terminated polyether binders for composite rocket propellants[D].Cranfield，UK:Cranfield University，2007.
[21］ LI D H，LIAO M Y.Study on the dehydrofluorination of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) copolymer[J].Polymer Degradation and Stability，2018，152:116-125.
[22］李东翰.液体端基官能化氟橡胶的制备、固化及其结构和性能研究[D].大连:大连海事大学，2018.
LI D H.Preparation，curing，structure and properties of end-functionalized liquid fluororubbers[D].Dalian:Dalian Maritime University，2018.(in Chinese)
[23］ WEN X M，ZHANG G P，CHEN K K，et al.Enhancing the performance of an HTPE binder by adding a novel hyperbranched multi-arm azide copolyether[J].Propellants，Explosives，Pyrotechnics，2020，45(7):1065-1076.
[24］ MANSON J A，SPERLING L H.Polymer blends and composites[M].Heidelberg，Germany:Springer，2012.
[25］常冠军.橡胶常用数据速查手册[M].北京：国防工业出版社，2012:196.
CHANG G J.Concise handbook of common data for rubber[M].Beijing:Natonal Defence Industry Press，2012:196.(in Chinese)
[26］杨冲冲.HTPE改性GAP粘合剂体系性能及应用研究[D].北京:北京理工大学，2016:17-65.
YANG C C.Study on properities and application of GAP binder systems modified by HTPE[D].Beijing: Beijing Institute of Technology，2016:17-65. (in Chinese)
[27］闫涛.纳米铝基含能复合物构筑及热反应特性研究[D].北京:北京理工大学，2020.
YAN T.Fabrication and thermal reaction characteristics of nano-aluminum based energetic composites[D].Beijing:Beijing Institute of Technology，2020.(in Chinese)
[28］ RIELLO D，ZETTERSTRM C，PARR C，et al. AlF₃ reaction mechanism and its influence on α-Al₂O₃ mineralization[J].Ceramics International，2016，42(8): 9804-9814.
[29］ TRUNOV M A，SCHOENITZ M，ZHU X Y，et al.Effect of polymorphic phase transformations in Al₂O₃ film on oxidation kinetics of aluminum powders[J].Combustion and Flame，2005，140(4):310-318.

[1]	XU Han， LUO Yongchen， NI Xiaodong， XIAO Bowen， ZHANG Feng， SU Xiaojie， ZHENG Quan， WENG Chunsheng. Operating Characteristics of Aluminum Powder Rotating Detonation Engine [J]. Acta Armamentarii, 2022, 43(5): 1046-1053.
[2]	ZHANG Jiangshi， LIU Jianhua. Effect of Dispersity on Explosion Sensitivity of Aluminum Powder [J]. Acta Armamentarii, 2021, 42(5): 979-986.
[3]	LI Junbao, LI Weibing, WANG Heng, YUAN Shuqiang, WANG Xiaoming, HONG Xiaowen, XU Heyang. Propagation Properties of Shock Wave in Aluminum Powder/rubber Composites under Explosion Loading [J]. Acta Armamentarii, 2020, 41(10): 2001-2007.
[4]	YAN Tao, REN Hui, MA Ai'e, JIAO Qingjie, WANG Huixin. Effect of Fluororubber Coating on the Properties of Nano-aluminum Powders [J]. Acta Armamentarii, 2019, 40(8): 1611-1617.
[5]	HE Ning， XIANG Cong， LI Wei， ZHANG Qi. Experimental Study on Deflagrating Characteristics of Nitromethane-aluminum Powder [J]. Acta Armamentarii, 2018, 39(1): 111-117.
[6]	ZHANG Wei, ZHOU Lin, ZHANG Xiang-rong, YANG Yan-peng, CAO Tong-tang. Experimental Study of Critical Diameter of DNAN-based Aluminized Melt-cast Explosives [J]. Acta Armamentarii, 2017, 38(4): 690-694.
[7]	WANG Wei-lun, LI Jian-min, YANG Rong-jie, LIU Zhu, LI Shi-peng. Influence of Organic Fluorine-contained Additives on Condensed Combustion Products of Aluminized Polyether Propellants [J]. Acta Armamentarii, 2017, 38(4): 704-710.