Effect of vacuum annealing on the characteristics of composite pellets containing DBSA-doped polyaniline and Fe nanoparticles

The DBSA-PANI-Fe composite powder with 50wt% of Fe nanoparticles was prepared by mechanically mixing the DBSA-doped polyaniline powder and Fe nanoparticles. The composite powder was compacted to pellets and the pellets were annealed in vacuum at 443,493,543, and 593 K for 60 and 120 min. The conductivity of the pellet increases markedly with increasing the annealing temperature up to 493 K, and then decreases with further increasing the annealing temperature. When the pellet was annealed at 493 K for 60 min, the increment of conductivity reaches a maximum value, and the conductivity is 2.6 times as large as that of the pellet unannealed. The conductivities of the pellets annealed under the conditions of 543 K/120 min, 593 K/60 min, and 593 K/120 min are lower than the conductivity of the pellet unannealed. For all the pellets, the variation in conductivity with temperature reveals that the charge transport mechanism can be considered to be 1-D variable-range-hopping (1-D VRH). The composite pellet shows a magnetic hysteresis loop independent of the annealing condition. The saturation magnetization is about 5.4×104 emu/kg. The saturation field and the coercivity are estimated to be 4.38×105 and 3.06×104 A/m, respectively. The crystalline structure ofFe nanoparticles in the composites does not change with the annealing condition. The annealing condition cannot destroy the polymer backbones.     

掺杂聚苯胺复合材料吸波性能的研究

用不同的化学合成方法分别制备了PANI-DBSA,PANI-HCl粉末,并将该粉末与石蜡共混复合,制备了聚苯胺复合材料,着重研究了这两种聚苯胺的用量对复合材料的电导率、微波吸收性能的影响。结果表明,PANI-DBSA复合材料的电导率突变较PANI-HCl复合材料早,在相同质量分数（小于70%）下,微波吸收能力均优于PANI-HCl复合物。     

十二烷基苯磺酰叠氮的合成

以十二烷基苯磺酸为原料、氯化亚砜为酰化剂,先合成中间产物十二烷基苯磺酰氯,然后合成目标产物十二烷基苯磺酰叠氮。实验结果表明,合适的反应条件为：n（氯化亚砜）︰n（十二烷基苯磺酸）=1.2︰1,反应温度50℃,反应时间5h,产品收率达85%,产品纯度大于90%。