New soluble,transparent and heat-resistant poly(ether amide)s based on 10,10-bis[4-(4-aminophenoxy)-3-methylphenyl]-9(10 H )-anthrone

Abstract

10,10-Bis[4-(4-aminophenoxy)-3-methylphenyl]-9(10H)-anthrone, as a new aromatic diamine, was synthesized from 9(10H)-anthrone by three-step procedure. Low-temperature polycondensation of this diamine with various aromatic dicarboxylic acid dichlorides produced a series of new cardo poly(ether amide)s with moderate to high inherent viscosities of 0.86–1.43 dL g⁻¹ while the weight-average and number-average molecular weights were in the range of 48,600–59,800 and 29,800–35,600 g mol⁻¹, respectively. All the polymers were readily soluble in polar solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, N-methyl-2-pyrrolidinone, dimethyl sulfoxide, and pyridine, and afforded transparent, flexible, and strong films upon casting from DMAc solvent. These polymers had glass transition temperatures of 254–297°C, 10% weight loss temperatures of 493–505°C, and char yields of 61–64% at 800°C in nitrogen. All polymers were amorphous and their films exhibited tensile strength of 80.7–101.4 MPa, elongation at break of 8.0–12.8%, and tensile modulus of 1.9–2.6 GPa. These polymers had low moisture uptake in the range of 2.13–4.02% and high transparency with an ultraviolet–visible absorption cutoff wavelength in the 322–375 nm range.