FeCl_3/共轭聚席夫碱复合材料的制备及介电性能

Synthesis and Dielectric Properties of FeCl_3/Conjugated Ploy Schiff Base Composite

由戊二醛和对苯二胺通过缩合反应合成席夫碱聚合物,并将其与三聚氰胺交联构筑立体网状结构,再与氯化铁配位形成具有"海胆状"结构的FeCl_3/席夫碱复合材料,利用傅里叶红外光谱和扫描电镜对其进行表征。通过对比Fe^(3+)掺杂量分别为0.02、0.03、0.04 mol时复合材料半年前后的电导率、介电常数实部与虚部、介电损耗角正切值和科尔-科尔半圆的改变,发现静置后复合材料介电参数均大幅增长,介电弛豫从无到有,并且在刚合成时其介电常数虚部在3.664×10~6~1.000×10~7 Hz为负值,但经过静置后却转变为正值。其中,静置半年后,Fe^(3+)掺杂量为0.04 mol的席夫碱铁盐聚合物在102 Hz处的介电损耗角正切从0.02升至6.13,电导率从7.15×10^(-7)S·cm^(-1)升至2.19×10^(-5)S·cm^(-1),介电常数实部与虚部也大幅增加,介电损耗机理为二重介电驰豫。

The conjugated Poly Schiff base（CPSB） was synthesized through condensation reaction between glutaraldehyde and p-phenylenediamine, then cross-linked with melamine to build a three-dimensional network structure, which was further doped with Fe3＋to form FeCl3/CPSB composite with urchin-like structure. Meanwhile,the conductivity（σ）, the real and imaginary parts of permittivity（ε′, ε″） and the dielectric loss tangent value（tanδε） occurred a significant increase and the Cole-Cole semicircle start from scratch, through comparing the initial and after 6 months value of CPSB with 0.02, 0.03, 0.04 mol Fe3＋doping content. The result displayed thatε″ was changed from a negative value to a positive value in 3.664 ×1061.000×107Hz after six months. Wherein,tanδεof composite with 0.04 mol Fe3＋doping content was increased from 0.02 to 6.13 and σ was increased from7.15×10-7S·cm-1to 2.19×10-5S·cm-1 in 102 Hz. The ε′ and ε″ were increased significantly as well. There are double relaxation mechanisms contributing the Debye relaxation to enhanced dielectric properties of the FeCl3/CPBS composite.