Modification of polyethylene properties by encapsulation of inorganic material

This study investigated the effect of various ceramic micro and nano fillers on the different properties (dielectric and thermal) of a polyethylene (PE) matrix. The fillers used were alumina (Al2O3) and boron nitride (BN). The polymer composites were prepared by ball milling and thick films containing wt. 50% of the inorganic phase were pressed. The encapsulation of the inorganic additives into the PE matrix was successfully achieved. The real part of the dielectric permittivity of a microcomposite containing Al2O3 was found to be close to that of the PE matrix value whereas the losses remained quite low. Thermal conductivity of PE was greatly improved: it increased by about 50% irrespective of the nature and size of the fillers. When the filler was nano BN, the breakdown strength was found to be slightly reduced by only 5%. This could be due to the size of the particles or to the high percentage of additives and the interface behavior of the fillers/matrix. Improvement of the PE surface resistance to discharges was achieved, specially with using nano-BN.

[1]  A. Vaughan,et al.  Surface resistance of epoxy/BN micro- and Meso-composites exposed to electrical discharges , 2013, 2013 IEEE International Conference on Solid Dielectrics (ICSD).

[2]  Y. Ohki,et al.  Experimental study on the factors determining the partial discharge resistance of polymers , 2012, 2012 IEEE 10th International Conference on the Properties and Applications of Dielectric Materials.

[3]  Y. Ohki,et al.  Development of epoxy/BN composites with high thermal conductivity and sufficient dielectric breakdown strength part II-breakdown strength , 2011, IEEE Transactions on Dielectrics and Electrical Insulation.

[4]  É. David,et al.  The dielectric permittivity of ceramic powders used in composite polymers , 2011, 2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena.

[5]  Xingyi Huang,et al.  A review of dielectric polymer composites with high thermal conductivity , 2011, IEEE Electrical Insulation Magazine.

[6]  Y. Ohki,et al.  Effects of nano-filler addition on partial discharge resistance and dielectric breakdown strength of Micro-Al2O3Epoxy composite , 2010, IEEE Transactions on Dielectrics and Electrical Insulation.

[7]  C. Rhee,et al.  Preparation and characteristics of nano-B4C/PVA particles and ultra high molecular weight polyethylene composites , 2010 .

[8]  Toshiya Watanabe,et al.  Wettability of ceramic surfaces -A wide range control of surface wettability from super hydrophilicity to super hydrophobicity, from static wettability to dynamic wettability , 2009 .

[9]  Shuhua Qi,et al.  Thermal conductivity of boron nitride reinforced polyethylene composites , 2007 .

[10]  Y. Ohki,et al.  PD Resistance Evaluation of LDPE/MgO Nanocomposite by a Rod-to-Plane Electrode System , 2006, 2006 IEEE 8th International Conference on Properties & applications of Dielectric Materials.

[11]  Michael G. Danikas,et al.  POLYOLEFIN INSULATION DEGRADATION IN ELECTRICAL FIELD BELOW CRITICAL INCEPTION VOLTAGES , 2005 .

[12]  M.F. Frechette,et al.  Introductory remarks on nanodielectrics , 2001, 2001 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.01CH37225).

[13]  A. Jonscher.  Dielectric relaxation in solids , 1983 .