High-performance aromatic thermosetting resins with hydroxyl and ethynyl groups

A novel hydroxyl-ethynyl-arene (HEA) resin was synthesized via Aldol condensation and Sonogashira reaction. The structure of the obtained resin was confirmed by the techniques of mass spectroscopy (MS), gel permeation chromatography (GPC), proton nuclear magnetic resonance spectroscopy (¹H-NMR), Fourier transform infrared spectroscopy, (FT-IR) and elemental analysis (EA). Differential scanning calorimetry (DSC) results showed an exotherm at the temperature range of 187°C-245°C, attributable to crosslinking reaction of the acetylene groups. After thermal cure, the obtained cured resin possessed excellent thermal stability. Thermal gravimetric analysis (TGA) in nitrogen showed the Td₅ (temperature of 5% weight loss) was about 400°C, and the char yield in nitrogen was about 78% at 900°C. The laminate composite of HEA resin was prepared and its mechanical and thermal properties were determined. The usefulness of the HEA resin as matrix for ablative composite was evaluated.