Molecularly Engineered Naphthalene-Based Poly(ether imide)s with Excellent Alkaline Corrosion Resistance

This study developed a class of naphthalene-containing poly(ether imide)s with exceptional comprehensive properties via a straightforward and cost-effective preparation process. The PEI exhibits excellent solubility in m-cresol, N-methyl pyrrolidone, and chloroform, with enhanced heat resistance (glass transition temperature increased from 223 to 279 °C). The tensile strength of PEIs rises from 72 to 118 MPa and Young’s modulus from 1.2 to 2.2 GPa, while maintaining an elongation at break exceeding 12%. Additionally, the material exhibited low water absorption (<1.3%), outstanding alkali resistance (increased from 4 to 78% mechanical property retention after 24 h in 10 wt % NaOH water solution at 85 °C), and favorable dielectric properties (dielectric constant: 2.85–2.97, dielectric loss: 0.005–0.006). Density functional theory calculations and molecular dynamics simulations elucidated the mechanistic role of the naphthalene ring in enhancing chain rigidity, disrupting molecular planarity, and improving hydrolysis resistance by sterically hindering nucleophilic attacks. This work provides a molecular design strategy for advanced microelectronics and extreme environments.