Synthesis and characterization of bisphenol-A ether diamine-based polyimide POSS nanocomposites for low K dielectric and flame-retardant applications

Polyhedral oligomeric silsesquioxane (POSS) - polyimide (PI) hybrid nanocomposites were prepared by a two-step approach, bisphenol-A ether diamine (BAED) and pyromelletic dianhydride (PMDA) in 1-methyl-2-pyrrolidone (NMP) were used to prepare polyamic acid (PAA) to which varying weight percentages of OAPS in NMP were added. During the second step, the polycondensation was effected by thermal imidization. The formation of hybrid nanocomposites was confirmed by using FTIR spectra. The thermal properties of POSS-PI nanocomposites were studied using differential scanning calorimetry and thermogravimetric analysis. The lowest dielectric constant 2.68 was achieved for 15 wt.% POSS-PI material when compared with the value of 3.34 for the neat PI. Data from thermal studies indicate that the incorporation of POSS into polyimide significantly enhanced the glass transition temperature (T-g), thermal stability, char yield and flame-retardant properties of hybrid nanocomposites than that of neat PI. The excellent combination of both dielectric and thermal properties of the material developed in the present study will find application in microelectronics.