Synthesis and characterization of ladder-like structured polysilsesquioxane with carbazole group

Poly(propyl carbazole silsesquioxane) (PPCSQ) with a high molecular weight (M (w) = 10,200) was synthesized by the direct hydrolysis of 9-[3-(trimethoxysilyl) propyl]-9H-carbazole with K2CO3, followed by a condensation reaction in an H2O/dimethylformamide (DMF) mixture solvent at 25 A degrees C. The obtained PPCSQ consisted of ladder-like structured siloxane bonds with carbarzole groups as the pendant group, where the distance between two carbarzole pendant groups through the siloxane backbone was 15.6 and the mean thickness of the siloxane backbone was 4.3 . This PPCSQ was thermally stable up to 450 A degrees C and the glass transition temperature was ca. 95 A degrees C, showing good film formablity by spin casting.