Abstract: ［Objective］To prepare organic polysilazane（PSN）composite coatings with excellent high temperature resistance at lower curing temperatures.［Methods］By introducing silane coupling agent modified silicon carbide（SiC） particles as heat-resistant reinforcement phase，the reaction kinetics of PSN in the thermal crosslinking reaction process were investigated and gradient programmedtemperature curing process was developed to evaluate the curing efficiency and high temperatureresistance of PSN based composite coatings with different SiC addition amounts at lower curingtemperatures（100-200 ℃）.［Results］The PSN composite coatings were prepared using the curing process of 130 ℃/2 h，150 ℃/2 h，180 ℃/2 h，and 200 ℃/2 h，while the addition of modified SiC significantly improved the high temperature resistance of the PSN composite coating. Notably，the high temperature resistance of PSN composite coatings increase with the addition of modified SiC，among which the PSN composite coating with 5% modified SiC content has the best thermal stability，the maximum temperature tolerance of the coating exceeds 400 ℃ and there are no cracks or defects on thesurface after the heat treatment at 400 ℃.［Conclusion］The modified SiC reinforced PSN compositecoatings prepared by gradient programmed temperature curing process can significantly reduce thecuring temperature of PSN coatings while effectively improving their high temperature resistance limit.

Key words: polysilazane, thermal crosslinking reaction, silicon carbide, silane coupling agent, high temperature resistant coating

摘要： 【目的】在较低固化温度下制备具有优异耐高温性的有机聚硅氮烷（ PSN）复合涂层。【方法】通过引入硅烷偶联剂改性碳化硅（ SiC）颗粒作为耐热增强相，探究 PSN在热交联反应过程中的反应动力学特性，构建梯度程序升温固化工艺，比较不同 SiC添加量的 PSN复合涂层在较低固化温度下（ 100~200 ℃）的固化工艺和耐高温性。【结果】 PSN复合涂层适合采用 130 ℃/2 h+150 ℃/2 h+180 ℃/2 h+200 ℃/2 h的梯度固化工艺，改性 SiC的加入显著提升了 PSN复合涂层的耐高温性。 PSN复合涂层的耐高温性随改性 SiC添加量的增加而增强，其中改性 SiC含量为 5%的 PSN复合涂层耐高温性最优，最高耐受温度超过 400 ℃且表面无开裂和缺陷出现。【结论】通过梯度程序升温固化工艺制备的改性 SiC增强 PSN复合涂层固化温度显著降低，同时耐高温极限得到有效提升。

关键词: 聚硅氮烷, 热交联反应, 碳化硅, 硅烷偶联剂, 耐高温涂层

CLC Number: 

• TQ637. 6