Control over phase structures’ evolution within the novel organic–inorganic hybrid system for achieving a comprehensive thermal, mechanical, and dielectric properties

Abstract

Significant challenges persist in developing high-performance, wave-transparent capable of operating above 500 ℃ using organic–inorganic hybrid materials. This study introduced a novel, highly reactive terminal carborane monomer, 4-(3-carborylphenyl) phthalonitrile (CB-Ph), to create a cross-linked network structure and inorganic phase. By integrating this with the conventional high-performance poly (phthalazine ether nitrate ketone) (PPENK), a novel organic–inorganic hybrid system was successfully constructed. Simultaneously, the modifications in the inorganic layer and phase structure of the material with increasing CB-Ph content were examined through nanoindentation and SEM analysis systems, establishing a structural foundation for optimizing the balance between thermal resistance, mechanical strength, and dielectric properties (balance of T-M−D). The thermal performance testing results indicates that the hybrid materials achieved high glass transition temperatures (Tg exceeding 500 ℃). This enhancement is attributable to the synergistic effects of cyanide side group micro-crosslinking and the phthalonitrile crosslinking network, which collectively restricted the movement of chain segments. The P-CB50 resin (PPENK+50 wt% CB-Ph), with its distinctive transition phase structure, boasts the most outstanding comprehensive performance. In terms of thermal stability, it not only features a Tg surpassing 500 ℃ In terms of thermal stability, it not only has a Tg exceeding 500 °C, but also loses only 5 % weight at 599.3° C in a nitrogen atmosphere (Td5%–N2 = 599.3 °C). Mechanical testing reveals that the flexural strength of the P-CB50 composite reaches an impressive 384.3 MPa, while the impact strength attains a significant 109.4 KJ/m2. Even at temperatures as high as 500 ℃, the dielectric constant of the P-CB50 composite material remains below 4, underscoring its superior high temperature wave-transparent properties. These results have firmly established a correlation between the phase structure of the hybrid system and the comprehensive performance of T-M−D, thereby laying a solid foundation for the development of high-temperature resistant and wave-transparent materials with enhanced overall performance.