title: Preparation and interfacial properties of a novel biodegradable polymer surfactant: poly(ethylene oxide monooleate-block-DL-lactide).
abstract: In this paper, we report a novel synthesis of poly(ethylene oxide monooleate-block-DL-lactide) (MOPEO-PLA) in the presence of stannous 2-ethylhexanoate catalyst. By utilizing the surfactant property and the reactive double bond of the amphiphilic MOPEO-PLA, various characteristics of PLA microspheres, such as surface and internal structure, surface morphology, release property, and so on, may potentially be controlled. MOPEO-PLA was found to be hydrophobic enough to prevent loss by dissolution into aqueous solution, which is often a problem for MOPEO. Furthermore, the interfacial tension measurements of a MOPEO-PLA/toluene/water system revealed that MOPEO-PLA had a good surface activity almost equal to that of MOPEO. The MOPEO-PLA/PLA blend films were prepared by solvent casting on a water layer. Contact-angle measurements of MOPEO-PLA/PLA blend films confirmed that the hydrophilic PEO segments were selectivity accumulated at the oil/water interface. Moreover, the surface free energy on the 'water side' of the MOPEO-PLA/PLA blend films was increased because of the increase in polar components as a result of the ether bonds of the PEO segments. Schematic illustration of the adsorption property of a) MOPEO-PLA with a high-molecular-weight PLA segment and b) MOPEO-PLA with a low-molecular-weight PLA segment at an ethyl acetate/water interface.
authors.affiliation: Department of Material and Energy Science, Graduate School of Environmental Science, Okayama University, 3-1-1, Tsushima-naka, Okayama 700-8530, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Nishino
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Kitamura
authors.forename: Akio
authors.initials: A
authors.lastname: Kishida
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Yoshizawa
mesh_terms: D001673:Biodegradation, Environmental; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D011091:Polyesters; D011108:Polymers; D013501:Surface-Active Agents; C507885:poly(ethylene oxide monooleate-block-DL-lactide); D011092:Polyethylene Glycols