Fully Conjugated Graft Copolymers Comprising a P-Type Donor–Acceptor Backbone and Poly(3-hexylthiophene) Side Chains Synthesized Via a “Graft Through” Approach

Tandem Kumada-Tamao catalyst-transfer condensation polymerization and Suzuki-Miyaura coupling for the synthesis of end-functionalized poly(3-hexylthiophene)

Successive Kumada-Tamao catalyst-transfer condensation polymerization of 2-bromo-5-chloromagnesio-3-hexylthiophene and Suzuki-Miyaura end-functionalization with pinacol arylboronate in one pot afforded poly(3-hexylthiophene) (P3HT) with a base-sensitive functional group at both ends. The use of poly(methyl methacrylate) (PMMA) bearing a boronic acid ester moiety at one end enabled one-pot synthesis of PMMA-b-P3HT-b-PMMA triblock copolymer.

Well-Defined Thermo- and pH-Responsive Double Hydrophilic Graft Copolymer Bearing a Pyridine-Containing Backbone

Graft copolymers have extensive applications in material science because of their tunable composition of backbone and side chains and diverse morphologies of aggregates. Recent studies mainly focused on the amphiphilic...

Programmable Assembly of π-Conjugated Polymers

π-Conjugated polymers have numerous applications due to their advantageous optoelectronic and mechanical properties. These properties depend intrinsically on polymer ordering, including crystallinity, orientation, morphology, domain size, and π-π interactions. Programming, or deliberately controlling the composition and ordering of π-conjugated polymers by well-defined inputs, is a key facet in the development of organic electronics. Here, π-conjugated programming is described at each stage of material development, stressing the links between each programming mode. Covalent programming is performed during polymer synthesis such that complex architectures can be constructed, which direct polymer assembly by governing polymer orientation, π-π interactions, and morphological length-scales. Solution programming is performed in a solvated state as polymers dissolve, aggregate, crystallize, or react in solution. Solid-state programming occurs in the solid state and is governed by polymer crystallization, domain segregation, or gelation. Recent progress in programming across these stages is examined, highlighting order-dependent features and assembly techniques that are unique to π-conjugated polymers. This should serve as a guide for delineating the many ways of directing π-conjugated polymer assembly to control ordering, structure, and function, enabling the further development of organic electronics.

Finely Designed P3HT-Based Fully Conjugated Graft Polymer: Optical Measurements, Morphology, and the Faraday Effect

In this work, our group synthesized and characterized a fully conjugated graft polymer comprising of a donor-acceptor molecular backbone and regioregular poly(3-hexylthiophene) (RRP3HT) side chains. Here, our macromonomer (MM) was synthesized via Kumada catalyst transfer polycondensation reaction based on ditin-benzodithiophene (BDT) initiator. The tin content of MM was then investigated by inductively coupled plasma-mass spectrometry (ICP-MS), which allowed for accurate control of donor/acceptor monomer ratio of 1:1 for the following Stille coupling polymerization toward our graft polymer (BP). The structures of the polymers were then characterized by gel permeation chromatography (GPC), NMR, and elemental analysis. This was followed by the characterization of optical, electrochemical, and physical properties. The magneto-optical activity of graft polymer BP was then measured. It was found that, despite the presence of the acceptor backbone, the characteristic large Faraday rotation of RRP3HT was maintained in polymer BP, which exhibited a Verdet constant of 2.39 ± 0.57 (10⁴) °/T·m.

Direct Synthesis of Chain-end-functionalized Poly(3-hexylthiophene) without Protecting Groups Using a Zincate Complex

Chain-end-functionalized poly(3-hexylthiophene)s (P3HTs) with benzyl alcohol (─PhCH₂ OH), phenol (─PhOH), and benzoic acid (─PhCOOH) groups are directly synthesized based on the Negishi catalyst-transfer polycondensation method utilizing the zincate complex of ^t Bu₄ ZnLi₂ . In this system, neither protection nor deprotection steps are required, and also providing a living polymerization system to control the molecular weight while maintaining a low molar mass dispersity (Ð_M ) of the obtained P3HT derivatives. Indeed, the chain-end-functionalized P3HTs can be synthesized along with controlled number-average molecular weights (M_n = 5100-20 000), low Ð_M (1.06-1.14), and high chain-end functionality (Fn = 46-86%). The Fn values for the alcohol and phenol groups are found to be high (86% for ─PhCH₂ OH and 71% for ─PhOH based on ¹ H NMR, respectively), as also confirmed by matrix-assisted laser desorption/ionization time of flight mass spectroscopy. The easily synthesizable chain-end-functionalized P3HTs will be applicable for the facile synthesis of block and branched polymers containing P3HT as well as its related semiconducting polymer segments.

Synthesis of di(ethylene glycol)-functionalized diketopyrrolopyrrole derivative-based side chain-conjugated polymers for bulk heterojunction solar cells

Synthesis of diketopyrrolopyrrole derivatives based side-chain conjugated polymers for solar cells.

All-conjugated P3HT donor PCDTBT acceptor graft copolymers synthesised via a grafting through approach

A generally applicable synthetic method for all-conjugated graft copolymers is presented.

Synthetic approaches towards structurally-defined electrochemically and (photo)redox-active polymer architectures

This review details synthetic strategies leading to structurally-defined electrochemically and (photo)redox-active polymer architectures,e.g.block, graft and end functionalized (co)polymers.

Structure, function, self-assembly, and applications of bottlebrush copolymers

Bottlebrush polymers are a type of branched or graft polymer with polymeric side-chains attached to a linear backbone, and the unusual architectures of bottlebrushes provide a number of unique and potentially useful properties. These include a high entanglement molecular weight, enabling rapid self-assembly of bottlebrush block copolymers into large domain structures, the self-assembly of bottlebrush block copolymer micelles in a selective solvent even at very low dilutions, and the functionalization of bottlebrush side-chains for recognition, imaging, or drug delivery in aqueous environments. This review article focuses on recent developments in the field of bottlebrush polymers with an emphasis on applications of bottlebrush copolymers. Bottlebrush copolymers contain two (or more) different types of polymeric side-chains. Recent work has explored the diverse properties and functions of bottlebrush polymers and copolymers in solutions, films, and melts, and applications explored include photonic materials, bottlebrush films for lithographic patterning, drug delivery, and tumor detection and imaging. We provide a brief introduction to bottlebrush synthesis and physical properties and then discuss work related to: (i) bottlebrush self-assembly in melts and bulk thin films, (ii) bottlebrushes for photonics and lithography, (iii) bottlebrushes for small molecule encapsulation and delivery in solution, and (iv) bottlebrush micelles and assemblies in solution. We briefly discuss three potential areas for future research, including developing a more quantitative model of bottlebrush self-assembly in the bulk, studying the properties of bottlebrushes at interfaces, and investigating the solution assembly of bottlebrush copolymers.

A facile route to electronically conductive polyelectrolyte brushes as platforms of molecular wires

Conjugated polyelectrolyte brushes grafted from a conductive surface and forming a 1D macromolecular pathway for charge transport are synthesized.

A facile strategy for the synthesis of conjugated polyelectrolyte brushes grafted from a conductive surface is presented. Such brushes form a platform of molecular wires oriented perpendicularly to the surface, enabling efficient directional transport of charge carriers. As the synthesis of conjugated polymer brushes using chain-growth polymerization via a direct “grafting from” approach is very challenging, we developed a self-templating surface-initiated method. It is based on the formation of multimonomer template chains in the first surface-initiated polymerization step, followed by the second polymerization leading to conjugated chains in an overall ladder-like architecture. This strategy exploits the extended conformation of the surface-grafted brushes, thereby enabling alignment of the pendant polymerizable groups along the template chains. We synthesized a new bifunctional monomer and used the developed approach to obtain quaternized poly(ethynylpyridine) chains on a conductive indium tin oxide surface. A catalyst-free quaternization polymerization was for the first time used here for surface grafting. The presence of charged groups makes the obtained brushes both ionically and electronically conductive. After doping with iodine, the brushes exhibited electronic conductivity, in the direction perpendicular to the surface, as high as 10^–1–10⁰ S m^–1. Tunneling AFM was used for mapping the surface conductivity and measuring the conductivity in the spectroscopic mode. The proposed synthetic strategy is very versatile as a variety of monomers with pendant polymerizable groups and various polymerization techniques may be applied, leading to platforms of molecular wires with the desired characteristics.