Intrinsic low-dielectric-constant polyimides based on a novel diamine having −CF3 groups and kinkable 1,4-diisopropylbenzene units

Polyimides (PIs) with low dielectric constants and optical transparency are of great interest in 5G/6G communication applications and in the microelectronics industry, where they are used as interlayer dielectric materials, wearable display devices and so forth. In this study, we designed and synthesized a novel fluorinated diamine called 4,4′-(1,4-phenylenebis(propane-2,2-diyl))diphenoxybis(2-(trifluoromethyl)-4-aminobenzene) (BPBTAB) monomer from bisphenol-P having diisopropyl benzene units and fabricated four novel BPBTAB-X PIs. These PI films possess excellent properties such as a low dielectric constant (1.13–1.84 at 1 MHz), high 5% loss temperature (395–491 °C), moderate glass transition temperature (223–254 °C), good tensile modulus (0.827–1.076 GPa), excellent optical properties (T₄₅₀ up to 83.37%), low moisture absorption (<0.63%) and good solubility in organic solvents. Hence, the as-synthesized PI films exhibit excellent comprehensive properties for high-frequency 5G/6G communication applications. © 2023 Society of Chemical Industry.