writer：Jie Kong*, Minjun Wang, Jianhua Zou and Linan An*
keywords：Hyperbranched Polyborosilazanes
source：期刊
specific source：ACS Appl. Mater. Interfaces, 2015, 7: 6733-6744
Issue time：2015年

High-temperature stable siliconborocarbonitride (SiBCN) ceramics produced from single-source preceramic polymers have received increased attention in the last two decades. In this contribution, soluble and meltable polyborosilazanes with hyperbranched topology (hb-PBSZ) were synthesized via a convenient solvent-free, catalyst-free and one-pot A₂+B₆ strategy—an aminolysis reaction of the A₂ monomer of dichloromethylsilane and the B₆ monomer of tris(dichloromethylsilylethyl)borane in the presence of hexamethyldisilazane. The amine transition reaction between the intermediates of dichlorotetramethyldisilazane and tri(trimethylsilylmethylchlorosilylethyl)borane led to the formation of dendritic units of aminedialkylborons rather than trialkylborons. The cross-linked hb-PBSZ precursors exhibited high a ceramic yield of > 80wt%. The resultant SiBCN ceramics with a boron atomic composition of 6.0–8.5% and a representative formula of Si₁B_0.19C_1.21N_0.39O_0.08 showed high-temperature stability and retained their amorphous structure up to1600 °C. These hyperbranched polyborosilazanes with soluble and meltable characteristics provide a new perspective for the design of preceramic polymers possessing advantages for high-temperature stable polymer-derived ceramics with complex structures/shapes.