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) (Mn = 600) (PEG600) as an initiator and l-lactide (l-LA), ɛ-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 1H NMR, 13C 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 °C for more than three weeks, which appeared to be more suitable for biomedical applications.

Two clearly Tg being observed in DSC thermogram indicated a micro-phase separation in PU-I. The corresponding PU films showed excellent mechanical properties with a tensile strength of 27.5 MPa and an elongation at break of 996%.Figure optionsDownload as PowerPoint slide