Oligoagarose-Graft-Polycaprolactone Copolymers: Synthesis and Characterization

in this paper, we combine hydrophilic oligoagarose (DPn = 10-15), issued from enzymatic degradation of the natural biopolymer agarose, with polycaprolactone, a synthetic biodegradable and hydrophobic polyester. To synthesize these amphiphilic graft copolymers, we use partially acetylated oligoagarose as macro-initiator in combination with tin (II) octanoate for the bulk polymerization of epsilon-caprolactone. The grafting was confirmed by NMR and SEC which showed a monomodal distribution. After removal of the acetyl protecting groups, copolymers with 30-60% free hydroxyl groups were soluble in water and insoluble in chloroform, thus indicating that they probably adopt micelle-like structures in aqueous solution with a PCL hydrophobic core and spherical oligoagarose side chains.