Synthesis and characterization of hyperbranched poly(ether sulfone)imides and MWCNTs‐COOH/NH₂ Nanocomposites

A new triamine 1,3,5‐tris{4′‐[4″‐(4″′‐aminophenoxy) phenylsulfonyl]phenoxy} benzene (TAPPSPB) was synthesized and successfully polymerized into hyperbranched polyimides (HBPIs) with commercially available dianhydrides BTDA and PMDA by A₂+B₃ method. HBPI‐PMDA‐AMT2/MWCNT nanocomposites were prepared by the reaction of TAPPSPB with PMDA and amino functionalized MWCNT by the conventional two step method by varying the percentage of MWCNT (1, 3, 5, and 7 wt%).The structure of the amine and the resulting hyperbranched polyimides were characterized by FT‐IR, ¹H, and ¹³C‐NMR analysis. The T_g and T_5% temperature of the HBPIs and nanocomposites were in the range of 229‐266°C and 430‐493°C, respectively. The results from DSC and TGA show that the T_g and the thermal stability of the HBPI‐PMDA‐AMT2/MWCNT nanocomposites are higher than that of pristine HBPIs. The dielectric constant (in the range of 3.05–8.54 at 1 MHz) and dielectric loss (in the range of and 0.64–0.87 at 1 MHz) increased with an increase of MWCNTs‐COOH/NH₂. SEM studies revealed that the MWCNT are evenly dispersed throughout the polymer matrix in the nanocomposites. X‐ray diffraction studies shows that the synthesized HBPIs and nanocomposites are amorphous in nature. POLYM. COMPOS., 40:600–614, 2019. © 2018 Society of Plastics Engineers