Synthesis and thermal analysis of silicon-containing bis-phthalonitrile resin with enhanced solubility

Silicon-containing bis-phthalonitrile (SiPN) resin has been synthesized via multi-step synthetic route and characterized through spectroscopic (H-1, C-13 NMR and FT-IR) and thermal methods. The curing behaviour of the resin has been studied using differential scanning calorimetry (DSC). The uncured resin showed melting peak at 421 K with curing onset at 477 K and curing exotherm peak appeared at 519 K and curing end-set at 573 K. The processing and the curing windows of resin were observed to be 62 K and 72 K respectively. The DSC analysis of cured resin showed no glass transition temperature up-to 623 K. The thermal stability of crosslinked resin was assessed via thermo-gravimetric analyser (TGA). The TGA analysis of cured resin displayed similar to 5% decomposition at 730 K and char yield of 68% at 1073 K under nitrogen atmosphere with limiting oxygen index (LOI) value of 44.7, calculated via empirical method using (Krevelen's equation). The resin showed 0.12% moisture absorption of when immersed in water for 48 h.

Automated summary

Silicon-containing bis-phthalonitrile (SiPN) resin was synthesized via multi-step synthetic route and characterized using spectroscopic and thermal methods. The curing behavior of the resin was studied using DSC, which showed specific temperature ranges for melting, curing onset, curing exotherm peak, and curing end-set. The thermal stability of the cured resin was assessed using TGA, and the resin exhibited a char yield of 68% at 1073 K.