Synthesis and characterization of thermally stable, hydrophobic hyperbranched polyimides derived from a novel triamine

A novel aromatic triamide 1,3,5-tri[4-(4-aminophenoxy)phenyl] benzene (TAPOPB) with prolonged chain segments and ether bonds was successfully prepared through a three-step reaction. Then a series of hyperbranched polyimides (HBPIs) were synthesized using A(2) + B-3 polycondensation from various commercial aromatic dianhydrides and TAPOPB. The HBPIs showed good solubility, thermal stability with glass transition temperatures (T-g) between 218 degrees C and 320 degrees C, and temperature at 10% weight loss of 502.1-561.7 degrees C in nitrogen atmosphere. Meanwhile, they had decent mechanical properties whose tensile strength and modulus were higher than 72.37 MPa and 1.039 GPa, respectively. Water uptake of less than 0.96% was obtained. The truncation wavelengths of the films were all greater than 400 nm with a good application prospect in UV protective coating. Most contact angles were more than 90 degrees, promising to be used as hydrophobic material.