聚硅乙炔改性硅硼碳氮前驱体的合成与性能研究

Synthesis and Properties of SiBCN Precursors Modified by PMSA

以聚硅乙炔(PMSA)为交联剂,改性硅硼碳氮(SiBCN)陶瓷前驱体,对前驱体的合成与裂解行为进行了详细研究。该前驱体陶瓷产率高(>80wt%),并且陶瓷产物致密、抗氧化性能优良。采用FT-IR对改性前驱体的结构进行了表征,采用DSC、TGA、XRD、马弗炉煅烧等方法对改性前驱体固化行为及其裂解产物的高温稳定性能、抗氧化性能进行了表征。研究结果表明:PMSA与SiBCN前驱体具有良好的相容性,低温下PMSA中的C≡C即可与SiBCN前驱体中的硅氢键发生加成反应,得到致密的块体材料,并显著提高前驱体的陶瓷产率,最高可达84.85%。空气气氛TGA和马弗炉煅烧实验表明裂解产物具有优良的高温抗氧化性能。

A novel modified SiBCN precursors（SiBCN/PMSA）were obtained by blending SiBCN with polymethylsilylacetylene（PMSA）as cross-linking agent. The structure of the modified precursors was characterized by FT-IR. The curing behavior of the modified precursor and the thermal stability, oxidative resistance of the ceramic residues were evaluated by DSC, TGA, XRD and muffle furnaces calcination methods. The results show that PMSA was compatible with SiBCN precursor. The ceramic yields increased significantly due to the cross-linking reaction between the C=C bonds of PMSA and the Si--H bonds of SiBCN at low temperature. The highest ceramic yield was 84.85%. The ceramic residues were dense and exhibited good oxidative stability at elevated temperature.