Experimental Study on the Electrical Properties of Polypropylene Composite Insulation Material Mixed with Nano-Clay

Polypropylene has been used in power capacitors and started to be employed in cables as insulation. Polypropylene mixed with natural nano-clay can be used as a nano-composite insulating material in practical engineering. The objective of this study was to evaluate the electrical properties of polypropylene filled with natural nano-clay through experimental and theoretical research, and to provide technical support for its application. Firstly, a comprehensive experimental platform for testing breakdown characteristics of materials is built. Then polypropylene samples having 0%, 2% and 6% nano-clay by weight were exposed to AC voltages at two different rates-of-rise while measuring the current. The important findings of this work were 1) the breakdown strength of the nano-clay filled sample was higher than the unfilled one; 2) the current density as a function of electric field intensity indicated a non-linear behavior with a saturation characteristics. And nano-clay with 2% by weight seemed to be the optimum concentration as well. The research results in this paper can provide reference for the application of polypropylene composite insulation materials.