Synthesis and characterization of a new biodegradable polyurethanes with good mechanical properties

In the paper, a new biodegradable polyurethane (PU, PU-I) was prepared: the prepolymer was synthesized via bulk ring-opening polymerization with poly(ethylene glycol) (M-n = 600) (PEG600) as an initiator and L-lactide (L-LA), epsilon-caprolactone (CL) as monomers, and the prepolymer was chain-extended with an isocyanate-terminated urethane triblock (macrodiisocyanate) to prepare the PU. The macrodiisocyanate, prepolymer and PUs were characterized by H-1 NMR, C-13 NMR, FT-IR, high resolution mass spectrometry (HR-MS), gel permeation chromatography (GPC), thermo gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The corresponding PU films showed excellent mechanical properties with a tensile strength of 27.5 MPa and an elongation at break of 996%, and also maintained mechanical properties in physiological saline at 37 degrees C for more than three weeks, which appeared to be more suitable for biomedical applications. (C) 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.