Preparation and Performance Study of Polyborosiloxane Resin and High‐Temperature‐Resistant Coatings

作者：Hang-Xuan Fan, Jing Ma, Tiantian Meng, Yuran Qiao, Zongpu Yang, Yuanchun Mu, Xiaoyu Li · 发表于：Advanced Engineering Materials · 年份：2026 · DOI：10.1002/adem.71002

Polyborosiloxane (BSiO) resins were synthesized via a one‐step solvent‐free method and used with nano‐Al 2 O 3 and nano‐TiO 2 to prepare high‐temperature‐resistant coatings. Monomer ratios (R/Si, Ph/R, B/Si) influenced network structure and thermal stability. Optimal performance was achieved at R/Si = 1.3, Ph/R = 0.2, and B/Si = 0.2, where T d , T d5% , T d10% , and 800°C ceramic residue increased by 15%, 18%, 29%, and 14%, respectively, relative to the boron‐free resin. 11 B‐NMR confirmed that boron was incorporated as a four‐coordinated species homogeneously dispersed in the siloxane network. Films cured at 100°C exhibited a tensile strength of 3.01 ± 0.44 MPa and toughness of 0.31 ± 0.04 MJ·m −3 . Boron inhibited pyrolytic rearrangement, preserving a largely amorphous structure after 1000°C. Coatings with a pigment‐to‐binder ratio of 2.5:1 and Al 2 O 3 :TiO 2 mass ratio of 0.5:1 showed Grade 0 adhesion, 6H hardness, and no cracking or yellowing after 600°C for 0.5 h. The organic‐to‐inorganic transformation during heating ensures sustained high‐temperature protection. This work provides a rational framework for designing high‐performance polyborosiloxane‐based thermal protection coatings.