High molar mass polymacromonomers based on methacryloyl end-functionalized oligo methacrylates (Mn ) 2410 g/mol) adopt the conformation of wormlike cylindrical brushes. Comparison of the absolute molar mass, Mw, determined by static light scattering and the contour length, Lw, of the molecules measured by SFM in the dry state revealed the length per vinylic main chain monomer of the cylindrical structure to be less than 0.1 nm, thus being much shorter than the maximum value of 0.25 nm. In solution this shrinkage could be quantified to 0.071 nm per monomer by Holtzer analysis of the scattering curves which in addition yielded the Kuhn statistical segment length lk ) 120 nm. GPC MALLS investigations of such samples showed an anomalous elution effect: After a regular elution at small elution volumes the molar mass of the eluting molecules increased drastically with increasing elution volume. Fractionation by GPC showed that this effect is caused by a fraction of extremely high molar mass molecules which elute by an unknown mechanism rather than by size exclusion.

The reactivity ratios of n-butyl acrylate (nBuA) with methyl methacrylate (MMA) and ω-methacryloyl-PMMA macromonomers (MM) in conventional and atom transfer radical copolymerization (ATRP) have been determined. For the copolymerization of nBuA with MMA, good agreement of the ratios is observed between conventional and controlled radical copolymerization, indicating that chemoselectivities in both processes are similar. The relative reactivity of the MM (1/r nBuA) in conventional copolymerization is significantly lower than that of MMA. It depends on the concentration of the comonomers but is not significantly influenced by the length of the MM. At high concentrations the relative reactivity decreases due to diffusion control of the MM addition. In ATRP the relative reactivity of the MM is much nearer to the value of MMA. This is explained by the different time scales of monomer addition in both processes: whereas the frequency for monomer addition is in the range of milliseconds for conventional polymerizations, it is in the range of seconds in ATRP; thus, diffusion control is less important here. This gives the opportunity to copolymerize at much higher concentrations than in conventional radical copolymerization. In addition, the graft copolymers obtained by ATRP have lower polydispersities.

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Comb-shaped poly(methy1 methacrylate) (PMMA) and poly(butyl acrylate) (PnBuA) grafted with PMMA were prepared by radical copolymerization of a-methacryloyl-PMMA with MMA and nBuA, respectively. The comb-shaped PMMA is characterized with respect to radius of gyration by using gel permeation chromatography equipped with a multi-angle laser light scattering detector. The radical copolymerization of the macromonomer with nBuA in toluene follows complex kinetics. The dependence of the relative reactivity of the macromonomer on absolute concentration and on the ratio of comonomers may be explained by preferential solvation of comonomers by segments of their own kind ("bootstrap effect") or even micelle formation. However, there is no clear evidence for the formation of micelles in toluene. In contrast, NMR studies show micelle formation in the preferential solvent dimethyl sulfoxide. The graft copolymers are transparent thermoplastic elastomers. Phase separation is demonstrated by differential scanning calorimetry and morphological studies.

The reactivity ratios of n-butyl acrylate (nBuA) with methyl methacrylate (MMA) and ω-methacryloyl-PMMA macromonomers (MM) in conventional and atom transfer radical copolymerization (ATRP) have been determined. For the copolymerization of nBuA with MMA, good agreement of the ratios is observed between conventional and controlled radical copolymerization, indicating that chemoselectivities in both processes are similar. The relative reactivity of the MM (1/r nBuA ) in conventional copolymerization is significantly lower than of MMA. It depends on the concentration of the comonomers but is not significantly influenced by the length of the MM. At high concentrations the relative reactivity decreases due to diffusion control of the MM addition. In ATRP the relative reactivity of the MM is much closer to the value of MMA. This is explained by the different time scales of monomer addition in both processes: whereas the frequency for monomer addition is in the range of milliseconds for conventional polymerizations, it is in the range of seconds or minutes in ATRP, thus diffusion control is less important here. This gives the opportunity to copolymerize at much higher concentrations than in conventional radical copolymerization. In addition, two-dimensional chromatography shows that the graft copolymers obtained by ATRP are much more homogeneous in terms of MWD and number of side-chains.Graft copolymers offer all properties of block copolymers but are usually easier to synthesize. Moreover, the branched structure leads to decreased melt Corresponding author.