Polyethylene nanocomposites for the next generation of ultra-low transmission-loss HVDC cables: insulations containing moisture-resistant MgO nanoparticles
Journal article, 2016

The use of MgO nanoparticles in polyethylene for cable insulation has attracted considerable interest, although in humid media the surface regions of the nanoparticles undergo a conversion to a hydroxide phase. A facile method to obtain MgO nanoparticles with a large surface area and remarkable inertness to humidity is presented. The method involves (a) low temperature (400 °C) thermal decomposition of Mg(OH)2, (b) a silicone oxide coating to conceal the nanoparticles and prevent interparticle sintering upon exposure to high temperatures, and (c) heat treatment at 1000 °C. The formation of the hydroxide phase on these silicone oxide-coated MgO nanoparticles after extended exposure to humid air was assessed by thermogravimetry, infrared spectroscopy, and X-ray diffraction. The nanoparticles showed essentially no sign of any hydroxide phase compared to particles prepared by the conventional single-step thermal decomposition of Mg(OH)2. The moisture-resistant MgO nanoparticles showed improved dispersion and interfacial adhesion in the LDPE matrix with smaller nanosized particle clusters compared with conventionally prepared MgO. The addition of 1 wt % moisture-resistant MgO nanoparticles was sufficient to decrease the conductivity of polyethylene 30 times. The reduction in conductivity is discussed in terms of defect concentration on the surface of the moisture-resistant MgO nanoparticles at the polymer/nanoparticle interface.

surface coating

MgO nanoparticles

thermal decomposition


HVDC cable


A. M. Pourrahimi

Royal Institute of Technology (KTH)

Love Pallon

Royal Institute of Technology (KTH)

Dongming Liu

Royal Institute of Technology (KTH)

Tuan Anh Hoang

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Stanislaw Gubanski

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

M. S. Hedenqvist

Royal Institute of Technology (KTH)

R. T. Olsson

Royal Institute of Technology (KTH)

Ulf Gedde

Royal Institute of Technology (KTH)

ACS Applied Materials & Interfaces

1944-8244 (ISSN) 1944-8252 (eISSN)

Vol. 8 23 14824-14835

Areas of Advance


Subject Categories

Polymer Technologies

Electrical Engineering, Electronic Engineering, Information Engineering





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