| Polyaniline have potential applications as their variable strueture, The Problems of Polyaniline are mainly focused on the Processibiling and stability of polyaniline.The conductive polyaniline was prepared with emulsion polymerization method in this article, dodecyl benzene sulfonic acid (DBSA) as the emulsifier and doping agent; and ammonium sulfate (APS) as oxidant. The polyimine acid (PAA) was prepared via solution polymerization with N-methyl-2- pyrrolidone as solvent, pyromellinc dianhydnde (PMDA) and 4, 4'-amino ether (ODA) as monomers at room temperature. Technics was fixed, Then polyimide was prepared. On this basis of, PAN/PI composites was prepared.After corrosion of ozone and ultraviolet irradiation for 100h, the conductivity of polyaniline is decreased, but as the irradiation time increases, electrical conductivity tends to level off, and still in the rang of semiconductor. The conductivity of PI is changed in the range of 0.50.6×10-4 S/cm before sand after 100 h irradiation. After UV irradiation for 50 h, the dielectric loss of PI is decreased from 0.33 to 0.05 before 50 kHz, whereas after 50 kHz, it remains at 0.05; The conductivity of PAN/PI composites decreased from the 1.4×10-4 S/cm to 1.1×10-4 S/cm after 100 h UV irradiation. After modified with polyaniline, the conductivity of polyimide is increased from 0.6×10-4 S/cm to 1.4×10-4 S/cm while the dielectric loss of the PAN/PI composites is increased gradually from 0.05 to 0.10. It is proved that polyaniline is decomposed completely at 400℃via thermal analysis, decocmposition temperature of PAN/PI composites was from 540℃to 670℃, and its stability is good enough in the ozone and UV environment.
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