Reduced sensitivity and enhanced thermal stability of ultrafine-CL-20/PDA/Estane5703 composites with double coating structure

A new type of energetic composite with a double-coating structure was constructed by in-situ polymerization of dopamine and water suspension method. Using CL-20 with a particle size of 200–500 nm as the main explosive, the core–shell structured CL-20-p (CL-20@PDA) was prepared via self-polymerization of dopamine on the surface of the CL-20. After that, thermoplastic polyurethane (TPU, Estane5703) was used as the binder, the CL-20-p was coated by water suspension method, and finally CL-20-p/Estane5703 composite was prepared. The structure and properties of the samples were characterized by SEM, AFM, FTIR, XPS, Raman, XRD, DSC and mechanical sensitivity test. The test results show that the CL-20-p is successfully coated by Estane5703, and the coating degree is high. Compared with the CL-20, the crystal phase transition temperature of CL-20/Estane5703 is significantly increased, and the mechanical sensitivity is greatly reduced. The CL-20-p/Estane5703 is superior to CL-20-p and CL-20/Estane5703 in enhanced thermal stability and reduced mechanical sensitivity.