Synthesis of P3HT-b-PS donor-acceptor diblock copolymer carrying pendant fullerenes at precise positions along the PS block

We present a strategy for the, synthesis of a well-defined rod-coil block copolymers of regioregular poly(3-hexylthiophene) and polystyrene (P3HT-b-PS), carrying pendant fullerenes (C-60) at precise positions along the PS block. The synthesis is achieved by combining 'living' anionic polymerization, Kumada catalyst-transfer polycondensation, and click chemistry. Azide terminated polystyrene was synthesized via anionic polymerization, while Cal moieties were grafted along the coil block with a [4+2] Diels-Alder cycloaddition reaction. The regioregular poly(3-hexylthiophene) rod donor block was end-capped with alkyne and was coupled with the azide terminated polystyrene via a copper catalyzed alkyne-azide cycloaddition. Size exclusion chromatography (SEC), NMR, and FT-IR spectroscopies were employed to confirm the synthesis of the diblock copolymers. Furthermore, the end-capping of the 'living' polystyrene (PS) with the diphenylethylene cyclobutene (DPE-CB) end-group was confirmed by matrix-assisted laser desorption/ionization time of -flight mass spectroscopy (MALDI-TOF MS). Thermogravimetric analysis (TGA) was employed for the estimation of the C-60 content in the block copolymer. The Co content at the coil 'block was 22 wt% and a strong quenching of photoluminescence (PL) was observed as the result of a large interfacial area between the P3HT and C-60 in the diblock copolymer. The bonding of C-60 across the PS block offers new routes to engineering stable morphologies, where the degree of organization/aggregation and/or crystallization of the acceptor material, of paramount importance for stable and efficient electron transport, may be controlled. (C) 2016 Elsevier Ltd. All rights reserved.