title: Degradability in vitro of polyurethanes based on synthetic atactic poly[(R,S)-3-hydroxybutyrate].
abstract: The aim of the present study was to determine the degradability of aliphatic polyurethanes, based on a different amount of synthetic, atactic poly[(R,S)-3-hydroxybutyrate] (a-PHB), in hydrolytic (phosphate buffer) and oxidative (H2O2/CoCl2) solutions. The soft segments were built with atactic poly[(R,S)-3-hydroxybutyrate] and polycaprolactone or polyoxytetramethylenediols, whereas hard segments were the reaction product of 4,4'-methylenedicyclohexyl diisocyanate and 1,4-butanediol.The selected properties - density and morphology of polymer surfaces - which could influence the sensitivity of polymers to degradation processes - were analyzed.The analysis of molecular mass (GPC), thermal properties (DSC) and the sample weight changes were undertaken to estimate the degree of degradability of polymer samples after incubation in environments studied.Investigated polyurethanes were amorphous with the very low amount of crystalline phases of hard segments.The polyurethane synthesized with a poly[(R,S)-3-hydroxybutyrate] and polyoxytetramethylenediol at a molar ratio of NCO:OH=3.7:1 (prepolymer step) appeared as the most sensitive for both degradative solutions. Its weight and molecular mass losses were the highest in comparison to other investigated polyurethanes.It could be expected that playing with the amount of poly[(R,S)-3-hydroxybutyrate] in polyurethane synthesis the rate of polyurethane degradation after immersion in living body would be modeled.
authors: Gdynia Maritime University, Department of Chemistry and Industrial Commodity Science, Gdynia, Poland.
authors: J
authors: J
authors: Brzeska
authors: Polish Academy of Sciences, Centre of Polymer and Carbon Materials, Zabrze, Poland.
authors: H
authors: H
authors: Janeczek
authors: Gdansk University of Technology, Chemical Faculty, Polymer Technology Department, Gdansk, Poland.
authors: H
authors: H
authors: Janik
authors: Polish Academy of Sciences, Centre of Polymer and Carbon Materials, Zabrze, Poland.
authors: M
authors: M
authors: Kowalczuk
authors: Gdynia Maritime University, Department of Chemistry and Industrial Commodity Science, Gdynia, Poland.
authors: M
authors: M
authors: Rutkowska
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D002072:Butylene Glycols / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D003035:Cobalt / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006868:Hydrolysis; D017953:Isocyanates / Q000737:chemistry; D008853:Microscopy; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D002072:Butylene Glycols; D017953:Isocyanates; D011091:Polyesters; D011140:Polyurethanes; C016240:polycaprolactone; D003035:Cobalt; C039681:1,4-butanediol; D006861:Hydrogen Peroxide; C018021:cobaltous chloride; D020155:3-Hydroxybutyric Acid
keywords: Polyurethane; atactic poly[(R,S)-3-hydroxybutyrate]; biomaterial; hydrolytic degradation; oxidative degradation