Investigation of the Thermal and Dielectric Behavior of Epoxy Nano-Hybrids by using Silane Modified Nano-ZnO

Abstract

The present work focuses on a comparative study of the thermal and electrical behavior of diglycidyl ethers of bisphenol-A (DGEBA) to uncover the suitability for its use in high performance applications. An epoxy nanohybrids coating was developed using aminosilane functionalized ZnO (1, 3, 5 and 7 wt%) as the dispersed phase and commercially available DGEBA as the matrix phase, with curing using triethylenetetramine (TETA). The structural features of these materials were ascertained by FTIR spectral studies, SEM and AFM analyses. The peak shift in all the samples at ∼ 1032 cm−1 explains the etheric linkage of ZnO-APTES core shell nanoparticles with the DGEBA virgin epoxy resin. The thermal behavior of the diglycidyl resins and their corresponding nano-hybrids was studied by TGA and DSC. The first decomposition stage of DGEBA neat epoxy resin starts at 325 °C and the second stage at 513.2 °C which varied in all epoxy nanocomposites. Further thermodynamic parameters are calculated using the Coats-Redfern method from TGA results to examine the thermal stability. The sample with 3% ZnO-APTES-DGEBA film exhibits the highest activation energy of 26.20 kj/mol. The dielectric permittivity, dielectric loss and AC conductivity variation with frequency, temperature and filler concentration were studied using an impedance analyzer. The variation in electrical behavior is more pronounced in 1 and 7% ZnO-APTES-DGEBA epoxy nanocomposites.