混杂聚硼硅氮烷的陶瓷化过程研究

合成了新型的陶瓷先驱 体混杂聚硼硅氮烷(H-PBSZ), 分析了其结构, 并采用TG-DTA、FT-IR、XRD以及SEM等分析手段对其裂解过程进行了研究. 结果表明, H-PBSZ结构中含有B-N、Si-N、B-H、N-H、Si-H等化学键, 随着裂解温度的升高, 含氢键逐渐减少直至消失, 最终得到BN和Si₃N₄的混合物. 在裂解过程中, 失重主要发生在100～400℃之间, 陶瓷产率约为83wt％. 裂解产物的结晶程度随着温度的升高逐渐增强, 800℃的产物基本上为无定形态, 微观形貌主要以球形颗粒为主; 1600℃的产物则已经晶化, 可以观察到层片状结构的h-BN及少量的α-Si₃N₄晶粒.

Ceramization of Hybrid Polyborosilazanes

New preceramic polymers-hybrid polyborosilazanes (H-PBSZ) were synthesized and characterized. The ceramization process of H-PBSZ was investigated by TGA, FT-IR, XRD and SEM. The results show that there exist bonds of B-N, Si-N, B-H, N-H, Si-H in the structures of H-PBSZ. With the increase of pyrolysis temperature, the bonds contained H atoms decrease till they disappear. The ultimate product is a mixture comprised of BN and Si₃N₄ . The loss of weight in the process of pyrolysis mainly occurs between 100℃ and 400℃, and the ceramic yield is about 83wt％. The pyrolytic product is crystallized as the temperature increases. The products pyrolyzed at 800℃ are almost amorphous with mainly spherical particles, while those pyrolyzed at 1600℃ are well crystallized, and h-BN crystal flakes and α-Si₃N₄ grains can be observed by SEM.