Self-Catalyzed Silicon-Containing Phthalonitrile Resins with Low Melting Point, Excellent Solubility and Thermal Stability

摘要

A series of silicon-containing self-catalyzed phthalonitrile derivatives (SiPNs) have been successfully synthesized from reaction of 4-(4-aminophenoxy)phthalonitrile (APN) with corresponding chlorosilanes. The chemical structures of the SiPNs were confirmed by spectroscopic techniques. The introduction of silicon-containing unit into the phthalonitrile structure has dramatically decreased the melting point from 143℃ for APN to 40–60℃ for the new SiPNs, which also exhibit improved solubility and are soluble in many common solvents. Differential scanning calorimetry analysis showed that they possess the self-catalyzed behavior with the temperature of exothermic peak due to the self-catalyzed reaction between 255 and 281℃. The cured SiPNs exhibit excellent thermal stability with glass transition temperature above 450℃, the temperature of 5% weight loss in range of 535–570℃ under nitrogen, and 543–562℃ under air. Their char yields at 1000℃ are in the range of 80.2–82.6% in nitrogen, and 10.1–12.5% in air, respectively.