Kong Jie, Wang Minjun, Zou Jianhua, An Linan
†MOE Key Laboratory of Space Applied Physics and Chemistry, Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P. R. China.
‡Department of Materials Science and Engineering, Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, Florida 32816, United States.
ACS Appl Mater Interfaces. 2015 Apr 1;7(12):6733-44. doi: 10.1021/am509129a. Epub 2015 Mar 23.
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 a ceramic yield higher 80%. The resultant SiBCN ceramics with a boron atomic composition of 6.0-8.5% and a representative formula of Si1B(0.19)C(1.21)N(0.39)O(0.08) showed high-temperature stability and retained their amorphous structure up to 1600 °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.
在过去二十年中，由单源前体聚合物制备的高温稳定硼碳氮化物（SiBCN）陶瓷受到了越来越多的关注。在本论文中，通过一种简便的无溶剂、无催化剂且一锅法的A2 + B6策略，合成了具有超支化拓扑结构的可溶性和可熔性聚硼硅氮烷（hb-PBSZ），即在六甲基二硅氮烷存在下，二氯甲基硅烷的A2单体与三（二氯甲基硅乙基）硼烷的B6单体发生氨解反应。二氯四甲基二硅氮烷中间体与三（三甲基硅甲基氯硅乙基）硼烷之间的胺过渡反应导致形成胺二烷基硼而非三烷基硼的树枝状单元。交联的hb-PBSZ前体的陶瓷产率高于80%。所得硼原子组成在6.0 - 8.5%之间且代表性化学式为Si1B(0.19)C(1.21)N(0.39)O(0.08)的SiBCN陶瓷表现出高温稳定性，并且在高达1600 °C时仍保持其非晶态结构。这些具有可溶性和可熔性特征的超支化聚硼硅氮烷为具有复杂结构/形状的高温稳定聚合物衍生陶瓷的前体聚合物设计提供了新的视角。
