Core-shell structure polydopamine and polyethylenimine co-assisted MoS2-BaTiO3/polyarylene ether nitrile nanocomposites for high-temperature resistant organic dielectrics

In this work, a novel nanoparticle ((MoS2-BT)@(PDA+PEI)) was constructed through two-dimensional molybdenum disulfide (MoS2) and zero-dimensional barium titanate (BT) via in-situ polymerization and co-modification of polydopamine (PDA) and polyethylenimine (PEI). Then the nanofillers were dispersed in the Polyarylene ether nitrile (PEN) matrix by film casting to obtain PEN/(MoS2-BT)@(PDA+PEI) nanocomposite dielectric films. Subsequently, the latter were subjected to chemical crosslinking at high temperature to obtain CPEN/(MoS2-BT)@(PDA+PEI) nanocomposites. The effects of filler content on the properties of PEN matrix composite films were investigated. The results indicate excellent compatibility between (MoS2-BT)@(PDA+PEI) and the PEN matrix due to the introduction of an organic modification layer, resulting in overall good performance of nanocomposite films, including good thermal stability with a glass transition temperature (Tg) exceeding 240 °C after chemical crosslinking. The dielectric constant of CPEN nanocomposites containing 40 wt% of the hybrid nanoparticles is 20.2 and the dielectric loss is 0.032 at 1 kHz, the dielectric constant-temperature coefficient of all CPEN nanocomposites is less than 6×10-4 °C-1 at the temperature range of 25-220 °C. In short, the incorporation of (MoS2-BT)@(PDA+PEI) effectively enhances the thermal, mechanical, and dielectric properties of PEN-based nanocomposites.