Programming molecular switches in water and ethanol via thermo-sensitive polymers for phase control in energetic crystals  

作　　者：Xinru Yang Yushi Wen Congmei Lin Feiyan Gong Zhijian Yang Fude Nie 

机构地区：[1]Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900,China

出　　处：《Defence Technology（防务技术）》2024年第8期75-88,共14页Defence Technology

基　　金：supported by National Natural Science Foundation of China(Grant Nos.U2130207,21875232,12372342);Foundation of President of China Academy of Engineering Physics(Grant Nos.YZJJZQ2023008,YZJJZQ2022006);the Foundation of China Academy of Engineering Physics(Grant Nos.CX20210015,CX20210027)。

摘　　要：The practical application of energetic materials, particularly 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20), is frequently impeded by phase transition challenges. In this study, we propose a novel strategy to enhance the stability of CL-20 by employing a thermo-sensitive polymer,poly(N-isopropylacrylamide)(PNIPAM), to modulate its phase transitions. Our approach involves the use of an in-situ polymerized polydopamine(PDA) shell as a platform for surface grafting through atom transfer radical polymerization, yielding a core-shell structured CL-20@PDA-PNIPAM. Through comprehensive characterization, the successful grafting of PNIPAM is confirmed, significantly enhanced the phase stability of CL-20. Notably, our core-shell structure exhibits a 13℃ increase in phase transition temperature compared to raw CL-20, thereby delaying the ε→a phase transition by over 80 min under combined thermal and solvent conditions. The enhanced stability is attributed to the hydrophobic nature of PNIPAM above its low critical solution temperature in water, which effectively shields the CL-20 crystal. These findings provide new insights into enhancing the stability and safety of energetic materials in complex environments, highlighting the potential of our molecular switch mechanism.

关 键 词：2 4 6 8 10 12-Hexanitro-2 4 6 8 10 12-hexaazaisowurtzitane(CL-20) Phase stability Polydopamine(PDA) Poly-N-Isopropylacrylamide(PNIPAM) Thermal and solvent effects 

分 类 号：TQ560.1[化学工程—炸药化工]