Design and synthesis of novel organosoluble chiral poly(amide-ether-imide-urea) containing l-leucine moieties in the main chain

N,N′-(pyromellitoyl)-bis{N-[4(4-aminophenoxy)phenyl]-2-(4-methyl)p-entanamide} (5), as a novel chiral diamine, is synthesized through dehydration of l-leucine and pyromellitic dianhydride followed by the treating with thionyl chloride and subsequent reaction with 4,4′-diamino diphenylether in dry tetrahydrofuran. Several novel optically active poly(amide-ether-imide-urea)s (PAEIUs) with inherent viscosities of 0.37–0.46 dL g⁻¹ are synthesized via the polymerization of compound 5 with various diisocyanates under different catalytic conditions. The obtained PAEIUs are characterized by means of FT-IR, ¹H-NMR, elemental analysis, and specific rotation measurement techniques. The new polymers are readily soluble in polar organic solvents such as N,N-dimethyacetamide, N,N-dimethyformamide, and dimethyl sulfoxide, while the evaluation of their thermal stability by thermogravimetric analysis and differential scanning calorimetry confirmed their moderate to good thermal stability. Compared with our previous work, here, we have different functional groups in the main chain which provide novel polymers with much better solubility while maintaining reasonable thermal properties.