Partially aromatic polyamides based on tetraphenylthiophene diamine: Synthesis and characterization

Abstract

Tetraphenylthiophene diamine (TPTDA) was prepared through a modified three-step route to achieve an improved overall yield. TPTDA reacted with succinic, adipic, suberic, sebasic, and fumaric acids via the Yamazaki phosphorylation method to yield novel partially aromatic polyamides (TPT series). A counterpart polyamide series based on p-phenylene diamine (Ph series) was also synthesized under the same conditions. All of the polymers were characterized by means of spectrochemical (Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance (NMR), and 13C-NMR) and thermal (differential scanning calorimetry and thermogravimetric) methods of analysis. Solubility of TPT polyamides was clearly improved due to the presence of the bulky aromatic diamine as well as flexible CH2—CH2 segments. The highly phenylated thiophene diamine moiety was recognized to improve thermal stability of the TPT polyamides in comparison with Ph polyamides (integral procedural decomposition temperature (IPDT) 480–517°C against 454–485°C). A favorable balance was recognized in regard to solubility, thermostability, and melting temperature in the TPT polyamides, especially TPT4 and TPT6. Therefore, they may be considered good candidates for processable polymers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1144–1153, 2000