Facile fabrication of titanium atomic modification polyimide‑silicone coatings via moisture/thermal dual curing for high temperature protection

The development of coatings with high thermal resistance and strong adhesion is desirable and challenging. Herein, we firstly reported a novel bismaleimide silicone (PMI-HSi) oligomer as well as the matching titanium-containing phthalate curing agent (PAEs). Subsequently, PMI-HSi and PAEs are semi-cured by a de-ethanolization reaction in humid ambient atmosphere. Resultant prepolymer molecular skeletons comprise acylimine bonds yielding strong hydrogen bonds, benzene rings, and titanium atoms, which facilitates the stability of the prepared coatings in high-temperature conditions. Ultimately, the final coating was successfully obtained via thermal initiated radical polymerization. The DTG results indicated that the residual carbon content of PMI-HSi@PAEs50% is as high as 63.9 %. And the Td5%, Td30% and THRI of PMI-HSi@PAEs50% were separately increased by 142.2 %, 29.2 % and 47.9 % compared with the control group. It is worth noting that PMI-HSi@PAEs50% can remain stable at a high temperature up to 600 °C, and no color changes and cracks appeared on the coating surface. All these results indicate that the as-prepared coatings exhibited excellent high temperature stability. In addition, due to the introduction of PAEs, the adhesion of PMI-HSi@PAEs50% reaches the highest grade of 0 and the hardness reaches 5H. Meanwhile, the reinforcement mechanisms were elucidated in detail. Overall, the as-prepared coating possesses high temperature resistance, strong adhesion, and great hardness, which possesses enormous potential for applications in the field of high-temperature protection.