Research on interface modification and electrical tree of PE/MMT composites

The phenomenon of electrical tree in polyethylene affects its service life and application in widely field. Our previous research works have showed that montmorillonite (MMT) introduced can improve electrical tree performance of polyethylene. In the present paper, organic processing methods by using intercalation agent and coupling agent are selected to modify spacing between laminar layers and surface characteristic of nano-montmorillonite. Polyethylene/nano-montmorillonite (PE/MMT) composites are prepared via melting intercalation method, the organic MMT content is 0.5%, 1%, 3%, and 5% in mass fraction respectively. It can be observed that infrared absorbance peaks of PE/MMT reduce by Fourier transform infrared spectrum (FTIR) due to hydrogen bonds formed between organic MMT and PE. The space charge characteristic and electrical tree properties of PE and PE/MMT are investigated. The test results reveal that the interfacial charge peak improved near cathode and internal space charge accumulation decreases obviously in PE/MMT composite. When content of organic montmorillonite is 0.5%, the PE/MMT composite has the minimum length and maximum density of electrical trees. Establish a model which can express the propagation of electrical tree in composite with layered inorganic filler simply, according to the testing results.