Linear dendritic hybrid

Fig. 6 Class C SPs. 14 Polyrotaxane " " 15 poly[2]catenane 18 linear dendritic hybrid chain from 7-oxanorbornene monomers substituted with two tapered monodentrons " and 20 SAMs of n-alkanethiolates on gold. Structures 16 [3]catenane and [3] rotaxane with two dibenzol[24]crown-8 rings 17 a-cyclodextrin 4-poly (ethylene oxide) and 19 tobacco mosaic virus are included for comparison.

Dendrigrafted polymer Hypergrafted polymer Linear dendritic hybrid FIGURE 5.12 Examples of dendritic polymer structures. 

Wood, K.C., Little, S.R., Langer, R., Hammond, P.T. A family of hierarchically self-assembling linear-dendritic hybrid polymers for highly efficient targeted gene delivery. Angew. Chem. 44(41), 6704—6708 (2005). doi 10.1002/Anie.200502152... 

Figure 28 Synthesis of 7-oxanorbornene macromonomer derived from two (G = 1)dendronsfoiiowedby ROMP polymerization into a linear dendritic hybrid architecture. (Courtesy of Macromolecules, 39(19) 5786, 1997. Copyright 1997 American Chemical Society.)...

Hybridization of Architectural States Dendritic-linear Copolymer Hybrids... 

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

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. 

The solution properties of hybrid-linear dendritic polyether copolymers are investigated by SEC with coupled viscometric detection from the same authors [12]. The results obtained show that the block copolymers are able to form monomolecular and multimole-cular micelles depending on the dendrimer generation and the concentration in methanol-water (good solvent for the linear blocks). 

Walter, M.V., Lundberg, P., Hult, D., Hult, A., Malkoch, M. A one component methodology for the fabrication of honeycomb films from biocompatible amphiphilic block copolymer hybrids a linear-dendritic-linear twist. Polym. Chem 4, 2680-2690 (2013)... 

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. 

Gitsov 1. Hybrid linear dendritic macromolecules from synthesis to applications. J Polym... 

Osano et al. [162] reported the synthesis of hybrid linear-dendritic ABA -type architectures, where A and B were hb poly(ether ketone)s and linear poly(ether sulfone)s, respectively. They prepared an AB2 monomer [3,5-bis(4 -fluorobenzoyl) phenol] to construct the hb segments, in an attempt to provide better control of the resultant hb structures than by utilizing the A2 + B3 approach. The monomer combination of linear block and AB2 monomer for the formation of ABA-type architecture are shown in Table 4, entry 4. Unreacted terminal groups of the ABA polymers were capped by teri-butylphenol and sodium 4-hydroxybenzene sulfonate. Such a flexible approach could allow different functional groups on the polymer chain ends simply by replacing the functional group on the phenol in the last part of the synthesis. 

Some of the hybrid linear-dendritic block copolymers have been subjected to a thorough characterization in solution [48,55] and in the solid state... 

Based on the various hybridization states of carbon, (Figure 1.2) at least four major carboskeletal architectures are known [6, 15]. They are recognized as (I) linear, (II) bridged (2D/3D), (III) branched and (IV) dendritic. In adherence with skeletal isomerism principles demonstrated by Berzelius (1832) these major architectural classes determine very important differentiated physicochemical properties that define major areas within traditional organic chemistry (e.g. linear versus branched hydrocarbons). It is interesting to note that analogous... 

Figure 7.1 Types of hybrid dendritic-linear macromolecules...

Dendritic growth hybrids are prepared using one or more functional groups of a preformed linear chain to effect the stepwise growth of one or more dendritic blocks via divergent synthesis. 

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