Modification of the structure and properties of polyketanils for applications in optoelectronics
Polimery 2005, No 7-8, 581
Polyketanils [Formula (II)] being the products of polycondensation of diamines with diketones [equation (1)] and differing in chemical structure have been obtained. The structures of these polymers, showing good thermal stability (Fig. 1), were characterized using elemental analysis, 13C NMR, FT-IR and UV-VIS methods. Effects of ketimine bond nitrogen atom protonation with 1,2-(di-2-ethylhexyl) ester of 4-sulfophthalic acid [DEHEPSA, Formula (I)] (Scheme B) on glass transition temperature (Tg, Fig. 2) and photoluminescence properties (Fig. 3) of polyketanils were investigated. It was found that changes in delocalization of p-electrons in polyketanil chain occur as a result of imino centers protonation. This contributes to bathochromic shifts of both absorption and emission bands. Additionally, the protonating agent used shows plastifying properties resulting in significant decrease in Tg. Shift of maximum emission band, caused by interaction of polymer with aprotic solvent (dimethylacetamide) or protogenic one (m-cresol, Scheme A), has been also determined along with interpretation of the mechanism of the latter solvent interaction.
Key words: poliketanile, protonation, self-organization, photoluminescence, thermal properties