Facile Syntheses, Morphologies, and Optical Absorptions of P3HT Coil-Rod-Coil Triblock Copolymers

Here we report syntheses, photophysical properties, and morphologies of a series of coil-rod-coil ABA triblock copolymers containing highly regioregular poly(3-hexylthio-phene) (P3HT) as the central rod block. A new methodology, based on the coupling reaction between living polymeric anions [polystyrene, polyisoprene, and poly(methyl methacrylate)] and aldehyde terminated P3HT, was successfully developed to synthesize the triblock copolymers with low polydispersities. This coupling reaction was effective for building blocks with a variety of molecular weights; therefore, a good variation in compositions of the triblock copolymers could be feasibly achieved. The non-P3HT coil segments and the solvents were found to exhibit noticeable effects on morphologies of the spin-coated thin films. Attachment of the coil segments to P3HT did not change the optical absorption of the P3HT segment as the block copolymers were dissolved in solution regardless the chemical structure and the molecular weight of the coil segment. Interestingly, different UV-vis absorption behaviors were observed for the spin-coated thin films of the block copolymers, which closely related to their morphologies. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3311-3322, 2010