TL;DR: In this paper, the breakdown process of polymers is discussed from the standpoint of the inherent properties such as chemical structure, structural irregularities, the presence of additives, molecular motion, and so on.
Abstract: Much experimental work has been done on the dielectric breakdown of solid dielectrics, and a number of breakdown theories have been proposed. Many problems, however, still remain on the breakdown process of polymers. Here, the breakdown process of polymers are discussed from the standpoint of the inherent properties of polymers such as chemical structure, structural irregularities, the presence of additives, molecular motion, and so on. Further, as for the long-time breakdown processes of polymer insulation systems, electrical degradations caused by (PD) and treeing breakdown have been mentioned as important factors. Using experimental results obtained in our laboratory together with those presented by others, our considerations for fundamental processes of electrical degradation are reported. Also, the behavior of dc trees caused by space charge accumulation are discussed with the nature of carrier injection and trapping in polymers, which are estimated by TSC and TL measurements.
TL;DR: The discovery and development of manmade polymer materials dates from the pioneering works of Goodyear (vulcanized rubber) and Hyatt (celluloid plastics) in the mid-nienteenth century, and to Baekeland (Phenol-formaldehyde resins) at the beginning of this century, the remarkable growth of the synthetic fiber, rubber, and plastics industries followed the preparative achievements of the I.C.I.
Abstract: Whilst the discovery and development of manmade polymer materials dates from the pioneering works of Goodyear (vulcanized rubber) and Hyatt (celluloid plastics) in the mid-nienteenth century, and to Baekeland (Phenol-formaldehyde resins) at the beginning of this century, the remarkable growth of the synthetic fiber, rubber and plastics industries followed the preparative achievements of the I.C.I. group in Cheshire (polyethylene), Carothers at Du Pont, Wilmington (linear polyesters and nylons) and the German chemists (polyvinyl halides) in the 1930's, and the U.S. Government Synthetic Rubber Program during World War II. The ability to vary chemical structure and composition (e.g. for copolymers) and physical structure (by fillers, plasticizers, thermal and mechanical treatments, processing methods) made it possible to create materials which could be tailor-made for a particular application. Thus the industries grew to the dominant positions they hold today.
TL;DR: In this paper, a short review of some aspects of nanocomposites regarding electrical tree growth and breakdown is presented. And a tentative proposal for the mechanisms of treeing and breakdown in nanocompositionites is also put forward.
Abstract: In this short review, we discussed some aspects of nanocomposites regarding electrical tree growth and breakdown. It appears that nanoparticles, properly mixed and dispersed in the polymer matrix, increase the breakdown strength and hinder the growth of electrical trees in the nanocomposite. Nanoparticles act as barriers obstructing electrical tree growth and delaying dielectric breakdown. This article also put forward a tentative proposal for the mechanisms of treeing and breakdown in nanocomposites.
TL;DR: In this paper, internal partial discharge in solid polymeric insulation is studied and a review of the progress in the understanding of PD induced aging of dielectrics can be found in this paper.
Abstract: The amount of literature on partial discharge (PD) and partial discharge induced degradation is vast. In the past 10-20 years significant progress has been made on research within partial discharge induced aging of dielectrics. Researchers now agree on the main mechanisms pertaining to this topic. With the advent of a new generation of dielectrics of which many properties now can be affected by the introduction of small amounts of nano-sized particles it seems to be a good moment to review the progress on the understanding of PD induced aging. Focusing on internal partial discharge in solid polymeric insulation this paper tries to identify achievements and at the same time challenges still to be solved.
TL;DR: In this article, the characteristics of water trees, the effect of aging parameters on water tree growth, and the possible mechanisms of growth are considered, emphasizing vented tree development in polyethylene insulating materials.
Abstract: Water tree growth in polyethylene cable insulation is discussed. The characteristics of water trees, the effect of aging parameters on water tree growth, and the possible mechanisms of growth are considered, emphasizing vented tree development in polyethylene insulating materials. The morphology of water trees, the characteristics of the tree-infested dielectric cable, and test methods and measures to reduce water treeing are discussed. >