Synthesis and characterization of hyperbranched polyether imides based on 1,3,5-tris[4-(4′-aminophenoxy)phenoxy]benzene

Abstract

A new triamine monomer 1,3,5-tris[4-(4′-aminophenoxy)phenoxy]benzene, was synthesized by a three step process using hydroquinone, 1-chloro-4-nitrobenzene and 1,3,5-trichlorobenzene. It was successfully polymerized with commercially available dianhydrides [3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA)] into hyperbranched polyimides (HBPIs) by the A₂ + B₃ method. Different monomer addition methods and different monomer molar ratios resulted in hyperbranched polyimides with amino and anhydride end groups. The structure of the resulting hyperbranched polyimides were characterized by FT-IR, ¹H-NMR, ¹³C-NMR and mass spectral analysis. All synthesized HBPIs were soluble in most common organic solvents. They also exhibit good thermal stability. The T_g of the HBPIs is in the range of 230–260 °C and T₁₀ values are above 450 °C. The dielectric constant of the synthesized HBPIs is in the range of 3.08–3.29 at 1 MHz and dielectric loss is in the range of 0.65–0.82 at 1 MHz.