Electrical behavior of nanocomposites based on LDPE-EVA blend

This work investigates thermoplastic polymeric blends based on low density polyethylene and ethylene vinyl acetate mixed together in 80:20 weight ratio. These blends have been mixed with montmorillonite and silica as fillers to obtain nanocomposites with different nanofiller amounts: percentage of 3% and 7% by weight have been chosen. The aim is to identify a new class of insulating materials for medium/high voltage equipment that could substitute the conventional ones characterized by high life cycle costs. The materials have been prepared by twin screw compounding following an optimized procedure that should lead to good quality of the blends. Suitable specimens have been processed by hot compression molding. Temperature, pressure and process time parameters, necessary to realize the samples, have been set to obtain a good thickness uniformity of the specimens. The preparation procedure has been studied in order to perform electrical tests characterizing the prepared blends. The electrical behavior has been investigated by means of electrical strength and electrical aging tests and the obtained results have been compared in order to better understand the nanofillers effects and determine which blends could lead to higher electrical performances.