Flexible polybenzoxazine thermosets containing pendent aliphatic chains

The rich chemistry of polybenzoxazines allows a wide range of molecular structure design by using appropriate starting materials. A new class of polybenzoxazines has been developed from benzoxazine monomers containing pendent long aliphatic chains. The monomers have been synthesized by the reaction of phenol or bisphenol A with two different long-chain aliphatic amines. The chemical structure of the monomers was confirmed by 1H nuclear magnetic resonance and Fourier transform infrared spectroscopy. The polymerization behavior of the monomers studied by differential scanning calorimetry shows exothermic peaks due to the ring-opening polymerization of benzoxazine monomers centered at 247255 degrees C. Dynamic mechanical analysis indicated that the glass transition temperatures Tg were in the range 8192 degrees C. The thermal stability of the polymers was also examined by thermogravimetric analysis, demonstrating that the weight loss temperatures decreased in comparison with that of traditional polybenzoxazine. Copyright (C) 2011 Society of Chemical Industry