超支化聚酯基双亲性大分子的合成及表征

Hyperbranched polyesters, PE-4G and TMP-5G, were synthesized via melt polycondensation of dimethylol propionic acid from pentaerythritol and trimethylol propane cores, respectively, and characterized by FTIR and 13C NMR. The results indicated that the degree of branching for the two hyperbranched polyesters were 0.43 and 0.42, and the hydroxyl value obtained by means of acetic anhydride method were 487 and 448, respectively. The PE-4G was further modified with butanedioic anhydride and polyethylene glycol (PEG), and thus amphiphilic macromolecules based on hyperbranched polyester (HBPE-PEG) with potential intriguing biocompatibility and degradability was prepared. This polymer exhibited excellent dissolubility, and diameter of micelles of the polymer in aquatic solution were about 12 nm determined by TEM and 22 nm by DLS, respectively. Moreover, the HBPE-PEG can increase the solubility of some hydrophobic guest molecules, such as pyrene, and diffusion-controlled characteristics were indicated in their releasing behavior.