Thermomechanical performances of polyethylene/alumina nanodielectrics by molecular motion in interface

Mechanical response under variation of temperature is regarded as valid way to detect the characteristics of molecular motion even involves in the microstructure. Dynamic mechanical analysis (DMA) is employed to conduct the thermo-mechanical measurements of LDPE/Al2O3 nanodielectrics. The DMA results pointed out that the glass transition temperature (Tg) increases at low nanoparticle loadings (<2 wt%) and then keeps a stable value at high loading, and its activation energy increases at low loadings. These results are associated with the restriction of molecular motion and its orientation in interfacial region. This work revealed that the restricted, rearranged molecular chains and strong attraction exist in interfacial region, which are responsible for the macroscopical properties (thermal, mechanical and electrical) of nanodielectrics.