Vol. 13, Issue 5 (2025)

Aromatic polyesters are a versatile class of high-performance polymers, yet their limited solubility and poor processability often restrict practical applications. To address this challenge, two novel dihydroxy monomers 3,5-dihydroxy-N-(naphthalen-8-yl)benzamide (Monomer A) and 3,5-dihydroxy-N-(naphthalen-7-yl)benzamide (Monomer B) were synthesized and polymerized with isophthaloyl chloride (IPC) and terephthaloyl chloride (TPC) by interfacial polycondensation. The resulting polyesters (PE-1 to PE-5 from Monomer A; PE-6 to PE-10 from Monomer B) were characterized with respect to solubility, inherent viscosity, and wide-angle X-ray diffraction (WAXD). Both polymer families exhibited good solubility in strong polar aprotic solvents, moderate viscosities, and amorphous character. Comparative analysis revealed that A-series (8-substituted) polyesters showed broader solubility and slightly higher viscosity values, whereas B-series (7-substituted) polyesters displayed somewhat tighter packing in XRD. These findings highlight how pendant substitution position on naphthyl units influences processability and amorphous character of aromatic polyesters.