Polyethylene nanocomposites for the next generation of ultra-low transmission-loss HVDC cables: insulations containing moisture-resistant MgO nanoparticles
Artikel i vetenskaplig tidskrift, 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

humidity-resistance

HVDC cable

Författare

A. M. Pourrahimi

Kungliga Tekniska Högskolan (KTH)

Love Pallon

Kungliga Tekniska Högskolan (KTH)

Dongming Liu

Kungliga Tekniska Högskolan (KTH)

Tuan Anh Hoang

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Stanislaw Gubanski

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

M. S. Hedenqvist

Kungliga Tekniska Högskolan (KTH)

R. T. Olsson

Kungliga Tekniska Högskolan (KTH)

Ulf Gedde

Kungliga Tekniska Högskolan (KTH)

ACS Applied Materials & Interfaces

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

Vol. 8 23 14824-14835

Styrkeområden

Energi

Ämneskategorier

Polymerteknologi

Elektroteknik och elektronik

DOI

10.1021/acsami.6b04188

PubMed

27203860