Thermal properties of diacetylene-containing polymer prepared from propargyl-terminated monomer with pyridine

A novel diacetylene-containing main chain-type polymer, poly[2,6-bis(4-propargyl-oxy-benzoyl)pyridine] (P₁), was synthesized via oxidative coupling reaction with a new propargyl-terminated monomer, 2,6-bis(4-propargyl-oxy-benzoyl)pyridine (M₁), which was incorporated a substituted pyridine into the molecular chain of model monomer, 4,4′-bis(propargyl-oxy)benzophenone (M₀). The structures of the new monomer and the resulting polymer were verified by Fourier transform infrared and proton nuclear magnetic resonance spectroscopies. Differential scanning calorimetry was used to investigate the curing behaviors of M₁ and P₁. The onset curing temperature of M₁ was 199.0°C, and the exothermic enthalpy of M₁ was 973.4 J g^-1, while the initial curing temperature for polymer P₁ reduced by 48°C and the exothermic enthalpy was almost half. Thermogravimetric analysis (TGA) showed the excellent thermal stabilities of M₁ and its polymer in argon atmosphere (the decomposition temperatures at 5% weight loss were 446°C for M₁ and 370°C for P₁ and their char yields at 800°C exceeded 71%). The above TGA data were superior to that of the model monomer (M₀) and its polymer (P₀) under the same conditions.