o:1607 Optimizacija umrežavanja izolacionog sloja srednje naponskih kablova na bazi etilen-propilen-dien polimera Optimization of the crosslinking for insulation layer of medium voltage cables based on ethylene-propylene-diene polymer : doctoral dissertation sr Thanks to its excellent properties, such as electrical resistivity, flexibility and resistance, ethylene-propylene-diene (EPDM) is widely used as an insulating material for electrical cables. Insulation layers of power cables, which make up 95% of electrical cables at nuclear power plants, are made of elastomers. Therefore, normal work can be seriously compromised if insulation of some cables is easily damaged or degraded. The performance of electrical cables depends on the physical integrity of the key components in the insulation layers, because micro-cracks can lead to loss of insulation characteristics. The use of polymeric materials for the production of electrical insulation is based on their favorable properties, which are related to their high stability. Oxidation as a major degradation process changes the functional characteristics of electrical insulations. The obtaining of insulating layers of current cables with satisfactory properties in an electric field were achieved by a well-chosen formulation consisting of high performance materials. In this dissertation, a research was carried out regarding the choice of polymer formulations with EPDM, testing the crosslinking of the appropriate EPDM formulation using peroxide compounds in order to slow down the degradation of insulation polymer layers of medium voltage cables. The proposed EPDM formulations were examined in terms of degradation, improvement of rheological, mechanical and electrical performances, and thermal stability. The possibility of reducing the concentration of zinc oxide in the formulation with simultaneous improved thermal and electrical stability due to the adverse impact of zinc oxide on the environment as well as the costeffectiveness of the insulation process on the cables were investigated. A new HPLC method that were developed could be used in the cable industry for routine measurements of percentage peroxide utilization in the process of making insulating polymer layers of EPDM. The results obtained showed that the appropriate types and concentrations of peroxides, as well as the amounts of ethylene in EPDM, can result in the development of stable insulation of medium voltage cables with excellent electromechanical efficiency. Biografija autora: list 129;Bibliografija: listovi 115-126. Datum odbrane: 21.09.2019. Chemistry and chemical technology 534136982 91552101 7170 91552100 534136982 2020-01-30T14:56:15.053Z 45 no 46 mentor Jelena N. 1987- Radosavljević 2019 63 mentor Ljubiša 1963- Nikolić 2019 63 predsednik komisije Suzana 1967- Cakić 2019 63 član komisije Goran S. 1966- Nikolić 2019 63 član komisije Marija NIkolić 2019 63 član komisije Snežana Ilić-Stojanović 2019 [13], 4-132 lista 5950546 http://phaidrabg.bg.ac.rs/o:1607 no yes 4 2020-01-30T14:56:15.320Z 70 Optimizacija, Peroksidno umrežavanje, EPDM, Reološkekarakteristike, Mehaničke karakteristike, Električnekarakteristike, Termička stabilnost, Cink-oksid, HPLC Optimization, Peroxide crosslinking, EPDM, Rheology characteristics,Mechanical properties, Electrical properties, Thermal stability, ZnO,HPLC 678.74:66.095.26(043.3) Т 390 1738 18A08 18A0803 2019