Dietheramine from an alkaline-stable phosphinated bisphenol for soluble polyetherimides

This study focuses on economic preparation of a phosphinated dietheramine for soluble polyetherimides. For this purpose, a phosphinated dietheramine, 1,1-bis(4-(4-aminophenoxy)phenyl)-1-(6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl)ethane (3), was prepared from the nucleophilic substitution of a alkaline-stable biphenol, 1,1-bis(4-hydroxyphenyl)-1-(6-oxido-6H -dibenz <c,e> <1,2> oxaphosphorin-6-yl)ethane (1), with 4-chloronitrobenzene using inexpensive potassium carbonate as catalyst, followed by catalytic hydrogenation. Light color, and foldable polyetherimides (PEIs) with good thermal stability, improved organo-solubility, and good flame retardancy were synthesized from the condensation of (3) with various aromatic dianhydrides in DMAc, followed by thermal imidization. Properties of the resulting PEIs were evaluated and compared with those of PEIs based on a commercially available dietheramine, 2,2-bis (4-(4-aminophenoxy)phenyl) propane (BAPP). The Tgs of the resulting PEIs range from 271 °C to 314 °C by dynamic mechanical analysis. The degradation temperatures (Td 5%) range from 453 to 467 °C in N2 atmosphere, and 435–451 °C in air atmosphere. The resulting PEIs also show good flame retardancy.