Environment-friendly synthesis of long chain semiaromatic polyamides

Long chain semiaromatic polyamides were synthesized by the reactions of p-phenylenediacetic acid with long chain aliphatic diamines, and characterized by Fourier transform infrared spectroscopy (FTIR) and by proton nuclear magnetic resonance (1H NMR). The thermal behaviors were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The solubility, dynamic mechanical, physical and mechanical properties of the polyamides were also investigated. The resultant polyamides have intrinsic viscosity ranging from 1.8 to 2.1 dl g–1, their melting temperatures range from 254 to 290°C, and their glass transition temperatures obtained from dynamic mechanical analysis are in the range 87–113°C. The physical and mechanical properties of long chain semiaromatic polyamides were compared with those the PA9T. The results show that the heat resistance and the mechanical properties of poly(decamethylene-pphenylenediacetamide) (PA10P) are near to those of PA9T, so PA10P is a promising heat resistant engineering plastic.