DocumentCode :
1779941
Title :
Electrical characterization of gamma-irradiated polypropylene
Author :
Mouaci, S. ; Saidi-Amroun, N. ; Belkahla, N. ; Saidi, M.
Author_Institution :
Mater. Phys. Lab., Univ. of Sci. & Technol., Algiers, Algeria
fYear :
2014
fDate :
19-22 Oct. 2014
Firstpage :
824
Lastpage :
827
Abstract :
The aim of this work is to understand the role of gamma radiation in trap creation and/or trapping and detrapping space charge mechanisms in isotactic polypropylene (iPP). The measurements are performed on 25 μm thick films: virgin polypropylene and one irradiated with gamma rays at a dose of 100 kGy. The experimental study is focused on measuring final thermostimulated discharge currents. At the end of the isothermal discharge process, obtained after charging under a DC field of 4 MV/m, the temperature was increased from 40 °C at a heating rate of 3 °C/mn. As a result, the discharging current of the irradiated film exhibits two peaks, the first one at 75 °C and the second one, of lower amplitude, at 122 °C. It was noticed that no peak was obtained in virgin iPP even at other charging temperatures. Indeed, gamma irradiation creates defects in the polymer that constitute traps of various depths, depending on the nature of the defect. The transient charging current exhibits oscillations (or multiple peaks) associated with charge packets and the current-voltage characteristic shows that the current is controlled by the space charge (IαV2). The differential scanning calorimetry DSC analysis shows a glass transition temperature of 9.4 °C and a crystallization temperature of 114 °C.
Keywords :
crystallisation; differential scanning calorimetry; gamma-ray effects; glass transition; heat treatment; polymer films; space charge; DC field; DSC analysis; charge packets; charging current; crystallization temperature; current-voltage characteristics; detrapping space charge mechanism; differential scanning calorimetry; electrical characterization; gamma ray irradiation; gamma-irradiated polypropylene; glass transition temperature; heating rate; irradiated film; isotactic polypropylene; isothermal discharge process; radiation absorbed dose 100 kGy; size 25 mum; space charge; thermostimulated discharge current; trap creation; virgin polypropylene; Current measurement; Films; Oxidation; Polymers; Radiation effects; Temperature measurement; gamma radiation; oxidation; polypropylene;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electrical Insulation and Dielectric Phenomena (CEIDP), 2014 IEEE Conference on
Conference_Location :
Des Moines, IA
Type :
conf
DOI :
10.1109/CEIDP.2014.6995744
Filename :
6995744
Link To Document :
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