Organic–inorganic rod–coil block copolymers comprising substituted polyacetylene and poly(dimethylsiloxane) segments

Abstract

In this article, we report the synthesis of rod-coil diblock copolymers comprising substituted polyacetylene and poly(dimethylsiloxane) (PDMS) segments through a precursor approach based on living polymerization. The precursor was prepared by sequential anionic vinyl polymerization of a designed template monomer, 2,3-di(n-hexylphenyl)-1,3-butadiene (n-HD), and the anionic ring-opening polymerization of a cyclic monomer, hexamethylcyclotrisiloxane (D 3 ). Block copolymers with well-defined molecular weights were obtained as demonstrated by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) spectroscopy, and matrix-assisted laser desorption ionization time-of-flight mass spectroscopy (MALDI-TOF MS). The polybutadiene segment of the precursor block copolymer was transformed into a substituted polyacetylene segment, or polyene, by dehydrogenation in the presence of 2,3dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The self-assembly behavior of the resulting rod-coil diblock copolymers in dilute solution was investigated by using dynamic light scattering (DLS) and transmission electron microscopy (TEM). It was found that the block copolymers showed a strong tendency to form vesicular aggregates. In some cases intermediate morphologies were observed, such as large size particles and vesicles with loosely packed thick walls. These morphologies developed further into regular vesicles through orientational assembly of the polyacetylene segments, as indicated by the blue shift in UV-Vis and fluorescence spectra. † Electronic supplementary information (ESI) available. See

Anionic Polymerizations of Bis(terphenyl) Substituted Butadienes for Precursors of Head‐to‐Head Substituted Polyacetylenes

“…Taking into account that the two substituents are attached to two adjacent carbons, the resulting dehydrogenation can be regarded as substituted polyacetylene with H‐H regiospecificity. Previously, similar strategy was proved to be successful to prepare substituted polyacetylenes with alkylphenyl substituents at 2,3‐position …”

“…Previously, similar strategy was proved to be successful to prepare substituted poly acetylenes with alkylphenyl substituents at 2,3-position. [19,24,25] The thermal stabilities of the precursor polymers and the corresponding H-H polyacetylenes were investigated using TGA under nitrogen atmosphere. As shown in Figure 10, the precursors underwent considerable weight loss from 400 to 500 °C, resulting in 5%-15% residue, while the dehydrogenated product gave residues of ≈55% as dark carbonaceous materials.…”

“Rod–coil” copolymers get self-assembled in solution

“…Following similar self-assembly principles, a number of rod-coil BCP systems containing other types of conjugated polymers, such as polyfluorene, [48][49][50][51] polyphenylene, 52,53 polyacetylene, 54 poly( p-phenylenevinylene) (PPV), 43,[55][56][57][58][59][60][61] and polyaniline, 62 also exhibit controllable multi-dimensional selfassembly behavior in solution. Polyfluorene-based rod-coil BCPs possess high thermal/chemical stability and good fluorescence quantum yields, and thus their self-assembly in solution is of increasing interest.…”

Recent advances in the solution self‐assembly of amphiphilic “rod‐coil” copolymers

“…Apart from the extensive studies on the self‐assembly of amphiphilic rod‐coil BCPs containing thiophene type blocks, a number of elegant work has recently focused on the self‐organization of rod‐coil BCPs with other types of conjugated polymers, including polyfluorene, polyphenylene, polyacetylene, poly( p ‐phenylenevinylene) (PPV), and polyaniline . As a typical example, fluorene‐based rod‐coil BCPs possess high thermal/chemical stability and good fluorescence quantum yields, thus their self‐assembly in solution has attracted considerable interest .…”