Effect of Different Size ZnO Particle Doping on Dielectric Properties of Polyethylene Composites

الملخص EN

In this article, low density polyethylene was used as a matrix polymer.

The ZnO particles with diameters of 30 nm and 1 μm were used as inorganic filler.

The nano-ZnO particles after surface modification would disperse in the matrix uniformly.

The nano-, micro-, and micro-/nano-ZnO/LDPE were prepared by melt blending.

During the experiment, the microstructures of different composites were characterized and discussed by SEM and DSC.

Besides, the micro- and nano-ZnO/LDPE underwent a breakdown test, conductance test, and dielectric spectrum test.

The microscopic experimental results showed that the ZnO particles dispersed uniformly in the LDPE matrix.

The crystallinity of composites was higher than that of pure LDPE.

Among them, the maximum crystallinity was 39.77% when the nano-ZnO particle size was 30 nm.

It was 16.1% higher than pure LDPE.

The macroscopic experimental results showed that the effect of micro- and nano-ZnO particle doping on breakdown properties of polymers was different.

Among them, the breakdown field strength of nano-ZnO/LDPE was the highest at 138.0 kV/mm, which was 8.24% higher than that of pure LDPE.

The micro-/nano-ZnO/LDPE took second place, which was still higher than pure LDPE.

As the thickness of samples increased, the thermal breakdown was the dominant factor in the breakdown test.

The AC breakdown field strength of all composites tended to decrease, and the reduction of micro-ZnO/LDPE was lower than that of nano-ZnO/LDPE.

Besides, the dispersion of the breakdown became better.

Moreover, the micro- and nano-ZnO particle doping could improve the conductivity characteristic of polymer effectively.

The dielectric constant and dielectric loss of composites increased with the increase of the particle size.