Title :
Dielectric properties of polymers with fractal architecture
Author :
Dantras, E. ; Caminade, A.M. ; Majoral, J.P. ; Lacabanne, C.
Author_Institution :
Lab. de Phys. des Polymeres, Univ. Paul Sabatier, Toulouse, France
Abstract :
A set of phosphorus-containing dendrimers involving three generations (g = 0, 1 and 2) has been investigated using dynamic dielectric spectroscopy and thermostimulated currents techniques. The dendrimers show a low temperature β mode with an Arrhenius type temperature dependence. Havriliak-Negami parameters of this mode are strongly influenced by the generation. For g = 0 dendrimer, a narrow TSC relaxation mode, with a quasi-Debye behavior has been also found. It has been associated with dipolar relaxation of aldehyde groups. This mode is observed in g = 1 and g = 2 dendrimers, with a mild modification of its characteristics due to interactions with phosphorus/sulfur strong dipoles (P = S groups). An additional metastable mode has been experimentally isolated. It might be due to structural relaxation.
Keywords :
dielectric polarisation; dielectric relaxation; fractals; glass transition; phosphorus; polymers; thermally stimulated currents; Arrhenius type temperature dependence; Havriliak-Negami parameters; TSC relaxation mode; aldehyde groups; dielectric properties; dipolar relaxation; dynamic dielectric spectroscopy; fractal architecture; glass transition associated mode; low temperature mode; phosphorus-containing dendrimers; polymers; quasi-Debye behavior; structural relaxation; thermostimulated currents technique; Dielectric measurements; Electrochemical impedance spectroscopy; Fractals; Frequency; Permittivity measurement; Polarization; Polymers; Powders; Temperature dependence; Temperature distribution;
Conference_Titel :
Electrets, 2002. ISE 11. Proceedings. 11th International Symposium on
Print_ISBN :
0-7803-7560-2
DOI :
10.1109/ISE.2002.1042947
