New polymer syntheses. IX. Synthesis and properties of new conducting polyazomethine polymers containing main chain cycloalkanone and pyridine moieties
Ki. Aly et Aa. Khalaf, New polymer syntheses. IX. Synthesis and properties of new conducting polyazomethine polymers containing main chain cycloalkanone and pyridine moieties, J APPL POLY, 77(6), 2000, pp. 1218-1229
Novel polyazomethines containing cycloalkanones or pyridine moieties were s
ynthesized by the polycondensation of 2,5-bis(m-aminobenzylidene)cyclopenta
none (BMAP, IV), 2,6-bis(m-aminobenzylidene)cyclohexanone (BMAH, V), 2,6-bi
s(p-aminobenzylidene)cyclohexanone (BPAH, VI), and 2,6-bis(m-aminostyryl)py
ridine (BMAS, WI) diamines with terephthalaldehyde in EtOH at 25 degrees C.
These polymers were yellow to orange in color, had reduced viscosities up
to 1.42 dL/g, and had electric conductivities as high as 10(-11)-10(-12) S
cm(-1). All th, polyazomethines were insoluble in common organic solvents b
ut dissolved completely in concentrated sulfuric acid. However, they were r
eadily hydrolyzed in concentrated H2SO4. X-ray diffraction diagrams showed
that the crystallinities of the polyazomethines were low. These azomethine
polymers showed high thermal and thermooxidative stability and exhibited no
appreciable decomposition up to 400 degrees C in air. The electronic spect
ra of the polymers indicated a large bathochromic shift of the pi-pi* absor
ption band (similar to 360 nm) that was due to the presence of C=N bonds in
the polymer main chain. Doping with iodine dramatically raised the conduct
ivity and produced dark brown to black colored semiconductive polymers with
a maximum conductivity on the order of 10(-7) S cm(-1) Furthermore, the mo
rphology of selected examples of the four polyazomethines was examined by s
canning electron microscopy. (C) 2000 John Wiley & Sons, Inc.