title: Influence of Diurethane Linkers on the Langmuir Layer Behavior of Oligo[(rac-lactide)-co-glycolide]-based Polyesterurethanes.
abstract: Three oligo[(rac-lactide)-co-glycolide] based polyesterurethanes (OLGA-PUs) containing different diurethane linkers are investigated by the Langmuir monolayer technique and compared to poly[(rac-lactide)-co-glycolide] (PLGA) to elucidate the influence of the diurethane junction units on hydrophilicity and packing motifs of these polymers at the air-water interface. The presence of diurethane linkers does not manifest itself in the Langmuir layer behavior both in compression and expansion experiments when monomolecular films of OLGA-PUs are spread on the water surface. However, the linker retard the evolution of morphological structures at intermediate compression level under isobaric conditions (with a surface pressure greater than 11 mN m-1) compared to the PLGA, independent on the chemical structure of the diurethane moiety. The layer thicknesses of both OLGA-PU and PLGA films decrease in the high compression state with decreasing surface pressure, as deduced from ellipsometric data. All films must be described with the effective medium approximation as water swollen layers.
authors: Institute of Biomaterial Science, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513, Teltow, Germany.|Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476, Potsdam, Germany.
authors: Anne-Christin
authors: AC
authors: Schöne
authors: Institute of Biomaterial Science, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513, Teltow, Germany.
authors: Klaus
authors: K
authors: Richau
authors: Institute of Biomaterial Science, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513, Teltow, Germany.
authors: Karl
authors: K
authors: Kratz
authors: Institute of Biomaterial Science, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513, Teltow, Germany.|Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476, Potsdam, Germany.
authors: Burkhard
authors: B
authors: Schulz
authors: Institute of Biomaterial Science, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513, Teltow, Germany.|Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476, Potsdam, Germany.
authors: Andreas
authors: A
authors: Lendlein
keywords: Brewster angle microscopy; Langmuir monolayer; poly[(rac-lactide)-co-glycolide]; polyesterurethanes; spectroscopic ellipsometry