Semi‐crystalline semi‐aromatic polyamides with varying length of polymethylene moiety: Synthesis and thermo mechanical property analysis

Abstract

In this work, a series of semi‐crystalline semi‐aromatic poly (ether amides) (PAT‐2–PAT‐10) with varying length of polymethylene moiety (2, 4, 6, 8 or 10 methyl groups) and number of ether groups in the main chain were synthesized by the nucleophilic substitution reaction of semi‐aromatic difluorobenzamido alkanes with 1, 4‐benzenediol at about 190–200°C, using K2CO3 as catalyst, N‐methyl pyrrolidione (NMP) as reaction solvent. And their viscosities, thermal, and mechanical properties were investigated. The inherent viscosities, glass transition, melting and degradation temperatures and tensile strength values of the synthesized polymers were in the range 0.141–1.829 dL g−1, 119.1–165.0°C, 272.4–345.4°C, and 371.4–451.1°C, and 61.2–79.2 MPa respectively. Moreover, they were found to have good solubility in concentrated sulfuric acid and trifluoroacetic acid at room temperature. The length of poly methylene group and ether bond in the polymer main chain had significantly influenced their thermo mechanical properties. The polyamides PAT‐6–PAT‐10 had better thermo mechanical property than that of commercial polyamide, PA6T/66.