Biodegradable crosslinked polymers based on triethoxysilane terminated polylactide oligomers

摘要

Lactic acid based polymers and their copolymers are widely used in biomedical aplications.Different properties are introduced by modifying the ocmposition.In this study,crosslinked polymers were produced from DL-lactide oligomers,which were functionalised with(3-isocyanatopropyl)triethoxysilane(IPTS) and crosslinked by acid catalysis in the presence of water without the use of solvent.The polymers were characterised by fourier transform infrared spectroscopy(FTIR) and differential scanning clorimetry (DSC), and thrie crosslinking density and compressive properties were measured.Functionalised linear an dstar-shaped iligomers were characterised by FTIR and DSC and also by ~1H NMR and size exclusion chromatography (SEC).According to ~1H NMR,79-95% of the hydroxyl groups were functionalised by IPTS during the early part of the synthesis.The formation of a strong polymer network was found to require a curing temperature of at least 90degC.The best mechanical properties were achieved with the oligomer initiated with 5% pentaerythritol.The properties of the polymer were then compressive yield strength 81 MPa,modulus 2260 MPa and 4.4% strain at yield point.