Abstract
A new pyridazine-containing aromatic diamine monomer,3,6-bis (3-aminophenoxy) pyridazine, was successfully synthesized by a nucleophilic substitution reaction of 3, 6-dichloropyridazine with meta-aminophenol in the presence of potassium hydroxide in dimethyl sulfoxide (DMSO) H-1-NMR, FTIR and HPLC-MS were employed to confirm the diamine and intermediates structure. In order to maintain the thermal and mechanical properties, and improve the glass transition temperatures (T-g) and optical property, the novel aromatic heterocyclic diamine monomer was employed to synthesize a series of polyimides by polycondensation with various commercial aromatic dianhydrides in N,N-dimethylacetamide (DMAc) via the conventional two-step method, i. e., ring-opening polycondensation forming the poly(amic acid) s (PAA) and further thermal imidization forming the pyridazine-containing polyimides. The resulting PAA possessed inherent viscosities in the range of 0.37 similar to 0. 50 dL/g. High quality polyimide films could be prepar