Synthesis And Characterization Of Biodegradeble Poly(ε-caprolactone)-Polyurethane

Biodegradable polyurethane materials have good mechanical properties, biocompatibility,blood compatibility,are taken as most valuable biomaterials in medical treatment.At present,biodegradable polyurethane materials are mainly applied to the repair and replacement of tissues ef human being,such as skin,manual blood vessel,bone and so on.They are most applied as carrier materials and body short term plants of medicine control system.When the medicine which uses these materials is planted to body,you don't need to take out by surgery after medicine is released. These materials will become safe materials,and discharge from body.So the appliance of Biodegradable polyurethane materials has become current international hot discussion.A series of polyurethane materials were synthesized using either poly-ε-caprolactone(PCL)or triblock copolymer poly-ε-caprolactone-poly(ethylene glycol)-poly-ε-caprolactone(PCL-PEG-PCL)as the soft segment,1,6-hexamethylene diisocyanate(HDI)as the hard segment,using stannous octoate as catalyst,and several diols as chain extenders,which displayed a broad range of properties for the need of biomedical appliance.First,fourteen kinds of polycaprolactone-polyurethanes with different ratio of soft segments/hard segments were synthesized using different molecular weight of PCL or PCL-PEG-PCL as the soft segment,HDI as the hard segment,and without chain extenders.The absorption peaks of N-H at 3391cm^-1,1738cm^-1and 1525cm^-1in FTIR revealed polyurethanes were synthesized.But these polyurethanes were very crisp, couldn't be applied broadly in biologic medical treatment without chain extenders. Second,polycaprolactone-polyurethanes with different ratio of soft segments/hard segments were synthesized using different molecular of PCL or PCL-PEG-PCL as the soft segment,HDI as the hard segment,and with seven chain extenders.FTIR revealed trevealed polyurethanes were synthesized.Mechanical test shows that the stress of PU2-7 and PU2-5-1 are 1 1MPa and 9.5MPa respectively,higher than others;The strain of PU2-3-1,PU2-4-1,PU4-2 and PU4-3 were 240%-270%.The drop-test showed that with the same soft segment,the angles were gradually increasing and then decreasing a little with molecular weight of chain extender increasing.With the same chain extender,the angles had direct ratio with molecular weight of soft segmens and concentration of hard segments.XRD showed crystallinity of polyurethanes decreaced with increasing of the molecular weight of the chain extenders.Last,the degradation behavior of two series of the polyurethane materials(PU2 and PU4)were investigated in Hanks(pH=7.4)at 37℃by examining changes in weight loss.The results showed that polyurethane materials degradated slowly,and their weight loss(except PU2-7)were only 2.5%in 40 days.After 40 days,the weight loss of polyurethane materials were improved,but no more than 3%.