Brush comb-like

Macromonomers provide an easy access to a large number of functional copolymers and controlled topologies, such as comb-like, star-like, bottle brush, and graft copolymers. These types exhibit exceptional solution or solid state properties compared to their linear homologues. 

Fig. 1 a—f. Various branched architectures obtained by the macromonomer technique a,b comb-like c,d star-like e brush f flower-like, a c, and e are poly(macromonomers) obtained by homopolymerization, while b, d, and f are graft copolymers obtained by copolymerization... 

Fig. 8 a-c The schematic illustrations of comb-like PEO-grafted polymer P(PEOMA) a, double grafted polymer brush P(BIEM-g-P(PEOMA)) b, and structure of hydrogel formed from polymer brush P(BIEM-g-P(PEOMA)) and a-CD c. Arrows indicate the crosslinking points [79]... 

The authors [228, 236] synthesized polymers of the type of so-called molecular brushes-poly(sodiumoxi) methylsylseskvioxanes (PSMSO). Molecular brushes one names comb-like polynners with high density of grafted side chains. They found anomalous low values of solutions viscosity of molecular brushes PSMSO and on this basis supposed, that at side branch length growth the qualitative changes of polymer macromolecule in solution and block occurred [228,236,237], which consisted oftran-... 

Figure 19.23 Schematic diagrams of linear, Y-shaped, and comb-like rod-coil block copolymer brushes. (Reproduced with permission from C.-S. Li, W.-C. Wu, Y.-J. Sheng and W.-C. Chen Effects of chain architectures on the surface structures of conjugated rod-coil block copolymer, Journal of Chemical Physics, 128, 154908, 2008. 2008 American Institute of Physics.)...

By grafting macromonomers onto a polymer backbone (see Section 3.4) a great variety of comb-like structures have been prepared and studied using rheometry. Bailly et al. [ 102 ] made combs ( bottle brushes ) having a 98% grafting density. They found that their plots of storage and loss moduli versus frequency followed power-law dependencies over five decades of frequency, and the power on the frequency was 0.6. 

Enhanced side branching of fibers by surfactant molecules was also observed. It was observed that the presence of a surfactant Span 20 could enhance the side branching of GP-1 fibers formed in propylene glycol (PG), which converts spherulitic fiber structures into comb-like and brush-like fibers when the surfactant concentration is below 0.77 wt% (Figure 2.8c-e) [4a]. With increase of surfactant concentration to above its critical micelle concentration (CMC) of 1.5 wt% in PG, the fiber network was converted back into a spherulitic fiber network (Figure 2.8f). However, the spherulitic fiber network formed in the presence of the surfactant is denser, and the elasticity of the material is twice that in the absence of surfactant. 

The next step is carding, where the cotton is passed between two surfaces set in close proximity to each other and covered with fine brush-like wires. The surfaces move in opposite directions or in the same direction at different speeds, resulting in a combing action that separates the fibers into a fine web. Getting the cotton to this opened condition causes most of the remaining finer trash to be removed. The fine web of fibers delivered from the card is condensed into a rope-like strand called card sliver and coiled into large cans. 

Polymers are macromolecules based on a large number of repeating units (monomers) covalently bound in a chain-like molecular architecture with a variety of compositions, structures, and properties. A large diversity of synthetic strategies and monomer combinations can be used to generate linear or nonlinear polymers, such as star-shaped, comb (brush), or branched polymers, and dendrimers (Fig. 11.1). 

Fig. 2. Selected architectures of block copolymers (a) diblock (b) triblock (c) comb copolymer consisting of flexible chains (d) rod-coil diblock copolymer consisting of a rodlike block and a coil-like block (e) hairyrods, i.e., comb-block copolymers consisting of rodlike backbone and coil-like side chains and (f) LC coil with a side-chain liquid crystalline (LC) block and a flexible block. Many other variations have been introduced, such as multiblock copolymers, block copolymers consisting of several rodlike blocks, or star-shaped block copolymers. Comb-coil block copolymers with dense packing of side chains are also denoted as molecular bottle brushes, as is illustrated in (g) by a simulated structure of an isolated molecule dissolved in a solvent. (Courtesy of Mika Saariaho.)...

Controlled/living polymerization techniques in combination with living ROP of NCAs can lead not only to linear but also to nonlinear chimeras. In this section we will describe the materials synthesized according to their structure star, comb, brush-block, and dendritic-like chimeras. 

Comb, Brush-Block, Dendritic-Like Chimeras... 

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