Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Four high-performance thiophene-aromatic polyamides of POT, PAT, PIOT, and POAT were synthesized under different conditions. The polymerization was carried out using 2,5-thiophenedicarbonyl dichloride (TDCl) and diamine as monomers. The chemical structure of polyimide was characterized by H-NMR and Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) tests showed that polyimide has outstanding thermal stability and mechanical properties. The temperature range corresponding to 5% thermal weight loss of the four polyamide resins was 353.5°C–411.0°C. The Young's modulus of POT and PIOT films of polyimide was 1441.65–2447.06 MPa, the tensile strength is 74.77–79.96 MPa, and the elongation at break is 5.69%–8.26%. These results pave the way for thiophene-aromatic polyamides to be used as high-performance special engineering plastics.

ABSTRACT
We synthesized four types of high-performance thiophene-based aromatic polyamides under mild conditions. These include POT (a polyamide derived from triazine and ethylenepiperazine), PAT (a phthalimide-triazine oligomer-based polyamide), PIOT (another phthalimide-triazine oligomer variant), and POAT (an advanced triazine-polyamide). The polymerization was carried out using 2,5-thiophenedicarbonyl dichloride (TDCl) and diamine as monomers. The chemical structure of the polyamide was characterized by H-NMR and Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) tests showed that the polyamide has outstanding thermal stability and mechanical properties. The temperature range corresponding to 5% thermal weight loss of the four polyamide resins was 353.5°C–411.0°C. This thermal property is comparable to that of the benzene-ring-containing semi-aromatic polyamide studied by Gang Zhang et al. (380°C–400°C). The Young's modulus of the POT and PIOT films of polyamide was 1441.65–2447.06 MPa, the tensile strength is 74.77–79.96 MPa, and the elongation at break is 5.69%–8.26%. These results pave the way for thiophene-aromatic polyamides to be used as high-performance special engineering plastics. It also provides a reference for the substitution of thiophene for the benzene ring.