In situ modification of ammonium perchlorate by energetic catalyst [Ni(N2H4)2](N3)2 — Achieving efficient catalysis for solid propellants

Introducing energetic metal complexes into solid propellants is an effective strategy for enhancing their energy release and improving the agglomeration of their catalysts. In this study, the metal complex [Ni(N 2 H 4 ) 2 ](N 3 ) 2 (NHA) was incorporated into hydroxyl terminated polybutadiene-based composite solid propellants, and its optimal catalytic ratio and catalytic mechanism for ammonium perchlorate (AP) were investigated through performance characterization. The optimal catalyst content was determined to be 1 %, whereby the exothermic peak temperature advanced by 26 ℃ compared to the blank control group, as examined by differential scanning calorimetry. The heat of explosion was 5744.98 J·g −1 . An increase in the burning rate while ensuring a pressure exponent below 0.5 (specifically, 0.399) was achieved simultaneously. The characterization of the flame structure demonstrated that the catalytic effect of NHA was concentrated in the condensed phase reaction zone of the propellant, which decreased in the Al agglomeration from 111.41 μm to 59.42 μm. Its catalytic effect is attributed to the rapid release of NiO particles during the decomposition of NHA, which formed a microchemical reaction zone on the AP surface, resulting in its increased porosity. The porous AP structure exposed more catalytically active sites, synergistically enhancing the catalytic efficacy.