A novel polystyrene with non-symmetrical zinc phthalocyanines as terminal group

A new non-symmetrical zinc(II) phthalocyanine (ZnPc) with an alkynyl functional group was prepared by an efficient mixed statistical condensation of 4-((4-ethynylbenzyl)oxy)phthalonitrile (1) and 4-(4-tert-butylphenoxy)phthalonitrile (2). The isolated unsymmetrical phthalocyanine molecule with additional three 4-tert-butylbenzyloxy groups to maintain solubility was used in the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition, better known as the “click chemistry”, as one of the precursors. The second component of the click reaction was polystyrene (PS) which was obtained by atom transfer radical polymerization (ATRP) and then its bromo end group was converted to azide by treatment with sodium azide. FT-IR, ¹H-NMR, ¹³C-NMR, MALDI TOF MS, UV–Vis, GPC, and elemental analysis techniques were used to characterize the precursors and targeted ZnPc-functionalized polystyrene. Molecular weight of obtained polymer was examined by gel permeation chromatography (GPC), thermal properties were also evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). It is observed that thermal stability of PS-ZnPc has been improved owing to high thermal stability of phthalocyanine group. Surface properties of PS-ZnPc thin films investigated by contact angle measurements indicate that it has more hydrophobic character when compared with PS-Br film.