[ACS Appl. Mater. Interfaces] Soluble and Meltable Hyperbranched Polyborosilazanes toward High-temperature Stable SiBCN Ceramics
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 Si1B0.19C1.21N0.39O0.08 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.