Synthesis and Self-Assembly of Poly(vinylpyridine)-Containing Brush Block Copolymers: Combined Synthesis of Grafting-Through and Grafting-to Approaches

Abstract

Synthesis of brush block copolymers (brush BCPs) enables the generation of BCPs with various block compositions and chain architectures, which determine the morphologies and functionalities of the polymeric materials. Here, we report a synthetic strategy for preparing structurally diverse brush BCPs via combined synthesis of the grafting-through and grafting-to approach. The polystyrene-based brush copolymer with an azide functionality is synthesized by sequential ring-opening metathesis polymerization of norbornene-based macromonomers, followed by post-polymerization modification. The final brush BCPs are then prepared by grafting various side chain polymers [poly­(2-vinylpyridine), poly­(4-vinylpyridine), or poly­(dimethylsiloxane)] onto the precursor BCPs with the desired ratio between the azido group on the backbone and alkynyl side chain polymer. This synthetic method is versatile in producing brush BCPs with various side chain types, backbone lengths, and grafting densities. In particular, it is observed that the morphologies of the brush BCPs can be controlled from lamella to cylinders to spheres by tuning the grafting densities. Furthermore, this interesting transition of self-assembled morphologies of the brush BCPs at different grafting densities is elucidated by the simulation results.

Amphiphilic Block Copolymer Grafted Multiwalled Carbon Nanotube Based Hierarchical Nanohybrids for Effective Epoxy Toughening

“…The morphological analysis of the grafted filler is highly essential as there is the possibility of formation of self-assembled nanostructures. ,− The grafted fillers themselves can form highly hierarchical nanostructures due to the inherent nature of the selected block copolymer to self-assemble into different morphologies. In our previous studies, it was observed that the same block copolymer was capable of forming different morphologies like spherical micelle, caterpillar-like, and gigantic octopus in the polymer matrix .…”

Poly(vinylpyridine)-containing block copolymers for smart, multicompartment particles

“…Significant improvement in the synthetic capability is required, as a number of difficulties are observed in synthesizing bottlebrush polymers containing PVPs via ring-opening metathesis polymerization, a popular approach for synthesizing ultrahigh molecular weight polymers. 174,175 In addition to the synthetic advances, new segment chemistry in combination with the PVP block would also diversify the scope of multicompartment particles.…”

Hierarchical Assemblies of Bottlebrush/Homopolymer Blends: Tailoring Phase Interfacial Curvature for Tunable Photonics†

“…Different from random coil linear BCPs, bottlebrush block copolymers (BBCPs) show highly stretched molecular conformations due to large steric repulsions among densely grafted polymer side chains. [ 5,28‐49 ] Consequently, polymer chain entanglements are greatly reduced relative to their linear analogues. This enables rapid self‐assembly of high‐MW BBCPs ( M w > 1.0 MDa) into ordered one dimensional (1D) photonic structures which can reflect visible structural colors.…”

“…Therefore, amphiphilic BBCPs were designed and synthesized for directed self‐assembly of inorganic nanocrystals by using strong hydrogen bonding, forming organic/inorganic hybrid materials with greatly enhanced contrast of dielectric constant. [ 36,46‐49 ] As a result, reflectivity greatly increased when compared to neat polymer materials. Typically, solution‐casting method has been used to prepare coating films via slow evaporation‐induced self‐assembly on planar surfaces such as on glass slides, which is challenging for real applications such as on a curved surface of a car.…”