SynopsisThis publication discusses the electronic, magnetic susceptibility, MS and GC-MS pyrolysis, X-ray powder diffraction, and electrical conductivity studies on metal phthalocyanine sheet polymers. The magnetic measurements over the range of magnetic field strengths 1025-6144 gauss indicated the absence of the intermolecular cooperative effect. MS and GC-MS studies indicate that all these metal phthalocyanine sheet polymers give benzene, cyanobenzene, and dicyanobenzene on thermal degradation. The electrical conductivity measurements showed that these polymers are semiconductor in nature.
A novel class of flame-and heat-resistant polymers has been synthesized by the thermal polymerization of maleimido-substituted aromatic cyclotriphosphazenes. The polymer obtained from tris-(aminophenoxy)tris(maleimidophenoxy)cyclotriphosphazene has good thermal stability and is noteworthy for its high char yield, viz., 82% at 800 °C in nitrogen and 81% at 700 °C in air. Graphite-fabric laminates prepared with this polymer did not burn in pure oxygen (limiting oxygen index 100%), even at 300 °C, and were tested for mechanical properties. Hexakis(4-maleimidophenoxy)cyclotriphosphazene and some fluorine-containing monomers have also been synthesized. The structures of these cyclic phosphazene precursors and polymers were characterized by FT IR spectrophotometry, 1H NMR, 19F NMR, and 31P solid-state magic angle spinning NMR spectroscopy, and mass spectrometry. The curing behavior of the polymer precursors and the thermal stabilities of the polymers were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA).
Metal phthalocyanine oligomers that possess peripheral carboxylic acid groups were prepared by the reaction of pyromellitic dianhydride, a metal salt, urea, and a catalyst. These materials have blue to purple colors with a metallic luster and are soluble in sulfuric acid, dimethylsulfoxide, dimethylformamide, and dimethylacetamide. Their thermal stability is high in an anaerobic atmosphere with char yields of 80–85% at 800°C. Elemental, spectral, and titrimetric analyses and thermal studies were carried out to characterize them.
The only work in the literature on the dipole moment of urea is that of Bergmann and Weizmann,2 who obtained a value of 8.6 in dioxane. A redetermination of the moment of this very important compound seems desirable for several reasons.
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