Linear-Dendritic Copolymers as Nanocatalysts

Functionalized poly(ethylene glycol) (PEG) containing four chloride end functional groups (PEG-Cl-4) was synthesized through reaction between cyanuric chloride and PEG-(OH)(2). Chloride end functional groups of PEG-Cl-4 were able to initiate the ring opening polymerization of 2-ethyl-2-oxazoline and star copolymers containing a PEG core, and poly(2-ethyl-2-oxazoline) (POX) arms were obtained. Polymerization was quenched using diethanolamine, and star copolymers containing hydroxyl end functional groups (PEG-POX-OH) were obtained. epsilon-Caprolactone was then polymerized using the hydroxyl end functional groups of star copolymers and amphiphilic linear-dendritic copolymers containing PEG and POX, and poly(caprolactone) (PCL) blocks were synthesized. Linear-dendritic copolymers were able to load the organic and inorganic guest molecules. Application of host-guest systems such as nanocatalyst for Heck chemical reaction was also investigated. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 2072-2080, 2009