LAUSR

Abstract Hyperbranched polymers have been proposed as potential carriers or host compartments for controlled drug delivery. In this work the solubilization of alkylphenols into aggregates formed by hyperbranched polyglycidol HPG and its ester derivative has been studied. HPG 17 was synthesized by ring-opening polymerization of glycidol, and then the ester HPG 4 -RBr 13 has been obtained by reaction of hPG 17 with 2-bromo isobutyryl bromide. The critical aggregate concentration CAC and micropolarity of aggregates were determined by using pyrene as fluorescence probe. CAC values obtained are 2.5 mM and 0.25 mM, for HPG 17 and HPG 4 -RBr 13 , respectively. Our results indicate that the hydrophobic effect is larger for HPG 4 -RBr 13 , and that their aggregates are more hydrophobic, than for HPG 17 . In addition, their sizes and sizes distribution were determined by DLS. The partition of phenols between the micellar and aqueous phase was studied by using the pseudo-phase model, and the results show that the partition coefficients increases with increasing length of the side alkyl chain, and are larger for HPG 4 -RBr 13 micelles than for HPG 17 micelles.