Side-chain Functionalized or Dendronized Copolymer Hybrids

4 SIDE-CHAIN FUNCTIONALIZED OR DENDRONIZED COPOLYMER HYBRIDS 

These were obtained by copolymerization of styrenic macromonomers containing dendritic pendant groups with styrene [16a] with a later extension to methacrylate-type copolymers [16b]. As these studies were carried out with 

Other efforts based on the macromonomer approach to homopolymers having dendritic side chains, include the work of Draheim and Ritter on acrylate and methacrylate derived structures having dendritic chiral side chains based on L-aspartic esters [17a], and of Xi and coworkers with poly(methacrylate) structures containing very small benzyl ether dendritic side-chains [17b]. Unfortunately, both of these approaches met with limited success due to a significant drop in degree of polymerization (DP) when the size of the dendron used as pendant group in the macromonomers increased from G-l to G-2. 

Much better results were obtained when dendronized structures were prepared via ring opening metathesis polymerization (ROMP) of norbornene 

The supramolecular transformation from sphere to cylinder is supported by X-ray data indicating that the spherical polymers adopt a cubic phase, whereas the cylindrical polymers adopt a hexagonal phase [23b]. Further studies involving a library of dendritic macromonomers led to the conclusion that the effect of DP on polymer shape is a general phenomenon [24], More recently, scanning 

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