Amphiphilic multi-arm star-block copolymers for encapsulation of fragrance molecules
Novel amphiphilic multi-arm star-block copolymers with a hyperbranched core, a hydrophobic inner shell, and a hydrophilic outer shell have been prepared from a commercial hyperbranched polyester macroinitiator by ring-opening polymerization of -caprolactone, followed by atom transfer radical polymerization of tert-butyl acrylate (tBuA). Hydrolysis of the tert-butyl groups was then used to convert the poly(tBuA) blocks to poly(acrylic acid), resulting in stable amphiphilic core-shell structures with significantly higher degrees of functionality than reported so far in the literature. A strong correlation between the maximum concentration of selected hydrophobic guest molecules and the concentration of amphiphilic star-block copolymer in aqueous solution was observed by 1H NMR, demonstrating the capacity of these copolymers to encapsulate and disperse significant loadings (up to about 27 wt.-%) of volatile hydrophobic molecules such as fragrances in water.
Keywords: amphiphiles ; atom transfer radical polymerization ; core-shell structure ; delivery systems ; encapsulation ; fragrances ; hyperbranched polymer ; ring-opening polymerization ; star-block copolymers
10221352 (ISSN), Cited By (since 1996): 2, Export Date: 25 September 2007, Source: Scopus, CODEN: MCHPE, doi: 10.1002/macp.200600449
Record created on 2007-03-28, modified on 2016-08-08