The effect of organoclay loading and matrix morphology on charge transport and dielectric breakdown in an ethylene-based polymer blend

Abstract

The effect of an organoclay on the electrical properties of a polymeric host is described. The matrix was composed of a blend of high and low density polyethylene, such that a wide range of different morphologies could be generated, to which an ethylene/(vinyl acetate) copolymer was added, to increase compatibility between the organoclay and the matrix and, thereby, improve the organoclay dispersion. The ratio between the compatibiliser and organoclay was found to be important in forming a well-dispersed system, as evinced by thermogravimetric analysis, X-ray diffraction and scanning electron microscopy, indicating the effectiveness of the chosen compatibilisation strategy. DC conductivity was found to be determined by the precise distribution of the organoclay throughout the system; changes in morphology and phase structure of the matrix polymer resulting from changes in imposed thermal history had little effect per se, but varying degrees of self-assembly of the organoclay facilitated by different residence times within the quiescent melt could result in changes in overall DC conductivity of several orders of magnitude. Consequent increases in DC conductivity led to reductions in DC breakdown strength, implying failure through some avalanche or thermal process. However, a monotonic increase in observed AC breakdown strength implies that the associated underlying failure process is then very different.

More information

Identifiers

ORCID for Allison, Vivienne Shaw: orcid.org/0000-0001-9726-312X

ORCID for Alun Vaughan: orcid.org/0000-0002-0535-513X

ORCID for Thomas Andritsch: orcid.org/0000-0002-3462-022X

Catalogue record

Export record

Altmetrics