|
A new class of polyhydrazones has been synthesized by the solution polycondensation from equimolecular amounts of aromatic dialdehydes such as para, meta, ortho-phthal aldehyde, 5,5'-methylene-bis-salicyl aldehyde (PPTA, MPTA, OPTA, MBSA) and dihydrazides, 5,5'-methylene-bis-salicylic dihydrazide (MBSDH), terephthalic dihydrazide (TDH), sebacic dihydrazide (SDH) in DMF-CH3COOH solution. The solubility characteristics, spectral, and thermal properties of the synthesized polyhydrazones and their metal chelates were also studied. These polyhydrazones and their metal chelates except the polyhydrazone prepared from OPTA-MBSDH were generally insoluble in common organic solvents. The thermogravimetric analysis of polyhydrazones showed 10% weight losses at 250∼350℃ and residual weight at 500℃ were 32.5∼62.5%. The decomposition temperature of higher relatively, and the metal chelates decrease in the following orders; Zn(Ⅱ)-Ⅱa > Ni(Ⅱ)-Ⅱa > Co(Ⅱ)-Ⅱa > Cu(Ⅱ)-Ⅱa.
|