Dendritic block copolymers

Tian, L. and Hammond, P.T. Comb-dendritic block copolymers as tree-shaped macromolecular amphi-philes for nanoparticle self-assembly, Chem. Mater., 18, 3976, 2006. 

Polymers and copolymers are among the most beneficial materials produced by synthetic chemistry. The invention and commercialization of new polymeric materials with radical new properties provides an opportunity to monopolize the market and justify the expense involved in the research and development. The commercialization of new polymers or copolymers always presents scale-up and design challenges. Scientists have recently developed new polymeric materials whose commercial impact has yet to be realized. Examples are semiconductive and conductive polymers and amphiphilic dendritic block copolymers. Other promising materials, such as polymers for (targeted) drug delivery and... 

E. Femandez-Megia, J. Correa, and R. Riguera, Clickable PEG-dendritic block copolymers, Biomacromolecules, 7 (2006) 3104-3111. 

Chapman TM, Hillyer GL, Mahan EJ, Shaffer KA. Hydraamphiphiles novel hnear dendritic block copolymer surfactants. J Am Chem Soc 1994 116 11195-11196. 

Gitsov 1, Frechet JMJ. Solution and solid-state properties of hybrid linear-dendritic block copolymers. Macromolecules 1993 26 6536-6546. 

Scheme 5.6. Attachment of poly(benzyl ether) dendrons to flexible hypercores results in dendritic block copolymers possessing monomer differentiated generations.

For polymer chemists it is interesting to know how well-known linear polymers can be linked with dendritic architectures and what the supramolecular consequences of this approach might be. Combination of dendrimers with linear polymers in hybrid linear-dendritic block copolymers has been employed to achieve particular self-assembly effects. Block copolymers with a linear polyethylene oxide block and dendritic polybenzylether block form large micellar structures in solution that depend on the size (i.e., the generation) of the dendritic block [10]. Amphiphilic block copolymers have been prepared by the combination of a linear, apolar polystyrene chain with a polar, hydrophilic poly(propylene imine) dendrimer [11] as well as PEO with Boc-substituted poly-a, -L-lysine dendrimers, respectively [12]. Such block copolymers form large spherical and cylindrical micelles in solution and have been described as superamphi-philes and hydra-amphiphiles , respectively. 

Figure 6. Schematic representation of three different architectures that can be considered dendritic block copolymers.

Self-Assemblies of Linear Dendritic Block Copolymers (LDBCs)... 

Linear-dendritic block copolymers composed of a dendron attached to a linear polymer have been shown to assemble into... 

T., Hult, A., and Malkoch, M. (2013) Multifunctional Poly(ethylene glycol) synthesis, characterization, and potential applications of dendritic-linear-dendritic block copolymer hybrids. Macromolecules, 46 (10), 3726-3736. 

The precursor polymer blend can be made out of (1) linear block copolymers, (2) AB block copolymers, (3) ABA block copolymers, (4) ABC block copolymers, (5) multiblock copolymers, (6) symmetrical and asymmetrical star block copolymers, (7) blends of polymers, (8) graft copolymers, (9) multibranched copolymers, (10) hyperbranched or dendritic block copolymers, and (11) novel brush copolymers. 

Gitsov I, Hamzik J, Ryan J, Simonyan A, Nakas JP, Omori S, Krastanov A, Cohen T, Tanen-baum SW. Enzymatic nanoreactors for environmentally benign biotransformations. 1. Formation and catalytic activity of supramolecular complexes of laccase and hnear-dendritic block copolymers. Biomacromolecules 2008 9(3) 804-ll. 

Figure 5.15 Graphical representation of the ROMP of wedge-type monomers to dendritic polymers and their self-assembly to dielectric mirrors (a). SEM images of dendritic block copolymers (b) were shown to assemble to...

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