Cross-linked Polyamides Prepared through Direct Bulk Michael Addition and Polycondensation from 1,6-Hexanediamine and Methyl Acrylate

Cross-linked polyamides(c PAs) were prepared through direct bulk Michael addition and subsequent polycondensation. Several mixed hexanediamine multi-esters(HDAMEs) were generated through the Michael addition of 1,6-hexanediamine(HDA) and methyl acrylate(MA) at50 °C with different HDA/MA molar ratios. Melt polycondensation of HDAMEs then proceeded at 150 or 170 °C in flasks to obtain viscous fluids,and curing was continued in tetrafluoroethylene molds to obtain c PA films. The Michael addition was monitored on the basis of FTIR and ESI-MS spectra. The c PA films were characterized by DSC, TGA, dynamic mechanical analysis, and tensile test. These directly prepared c PAs exhibited Tg of 1–39 °C, tensile strength of up to 45 MPa, and strain at break from 18% to 40%. The c PAs with high tensile strength and good toughness were successfully synthesized through the direct bulk Michael addition from HDA and MA followed with polycondensation.