Im. Elanwar et al., DIELECTRIC-PROPERTIES OF SOME SEMICONDUCTING PHTHALOCYANINE PIGMENTS, Polymer-plastics technology and engineering, 37(1), 1998, pp. 41-55
A different series of metal phthalocyanine and biphthalocyanine pigmen
ts have been prepared via the urea fusion technique in the dry method
by the condensation of phthalic anhydride, urea, and metal salt (at 22
0 degrees C for 4 h in the presence of ammonium molybdate as a reactio
n promoter) in the synthesis of a phthalocyanine derivative, or phthal
ic anhydride, pyromellitic dianhydride, urea, and metal salt in the sy
nthesis of the biphthalocyanine derivatives. The dielectric properties
of the prepared pigments were studied at various ranges of temperatur
es and frequencies. The dielectric constant epsilon' and the dielectri
c loss epsilon '' for the various complexes were calculated and discus
sed. The effect of various types of metal ion and also bromination on
the dielectric properties of these compounds were studied. A polarizat
ion and dielectric relaxation process for such compounds were proposed
.