In situ precise construction of surface-activated boron powders: A new strategy to synergistically improve the interface properties and enhance combustion performance of boron

Abstract

Boron powder (B) is considered to be the most ideal fuel for fuel-rich rocket propellants due to its high calorific value. However, substances such as B2O3 and H3BO3 on the surface of B powder not only reduce the combustion efficiency of B, but also seriously deteriorate the preparation process of hydroxyl-terminated polybutadiene (HTPB)-based propellants, making it difficult for B powder to be used in fuel-rich rockets propellant. Herein, two weak polarity molecules, 1 H, 1 H, 2 H, 2 H-perfluorodecyltrichlorosilane (denoted as PT) and decyltrichlorosilane (denoted as DT), are proposed to be directly anchored on the surface of B powder by chemical bonding to change the surface of B powder. The textural and chemical properties of the B powder and the surface-activated B powders, as well their reaction and combustion performance under different conditions, were studied in detail using various experimental methods. The results show that B@PT and B@DT activated by 1 H, 1 H, 2 H, 2 H-perfluorodecyltrichlorosilane and decyltrichlorosilane respectively have better reaction and combustion performance than B powder. The perfluorodecyltrichlorosilane on the surface of B@PT can release radicals such as CnF2n+2 and CnF2n with strong oxidizing properties during the thermal decomposition process, which can corrode the oxide layer on the surface of B powder and can significantly improve the combustion performance of B powder. This research is expected to enable the large-scale application of B powder in HTPB-based fuel-rich rocket propellants.