Preparation And Characterization Of POC-co-PCL Biodegradable Bioelastomer And Its Electrospun Fiber Mats

Nowadays,with the development of both materials science and biomedical science,biomedical materials have been widely used in many aspects such as drug controlled release carriers,surgical sutures,and tissue engineering scaffolds.Among them poly(1,8-octanediol-citric acid)(POC)bioelastomer,as a kind of the network type polyester biomaterials,has excellent biocompatibility and biodegradability.In addition,polycaprolactone(PCL)has excellent biocompatibility,non-toxicity,biological resorbability,etc.It’s unique structural characteristics enable it to be copolymerized or blended with many compounds.In this thesis,the POC-co-PCL(POCL)prepolymer was prepared successfully by in situ melt polycondensation of 1,8-octanediol and citric acid in the presence of PCL.On the one hand,the POCL prepolymer was thermocured to produce the POCL degradable bioelastomer that exhibited excellent properties.On the other hand,POCL prepolymer was physically blended with PCL to perform electrospinnig and the POCL/PCL fiber mats were obtained.The fiber mats could be used as porous scaffolds in the field of tissue engineering.The main results are as follows:(1)POCL degradable bioelastomers were prepared by in situ melt polycondensation and subsequent thermocuring.The effects of the molecular weight of PCL,the percentage of loaded PCL and the curing time on the performances of POCL bioelastomers were explored.The structure and properties of POCL elastomers were characterized by means of GPC,XRD,1H-NMR,DSC,DMA,etc.The following conclusions were obtained: the POCL bioelastomer could be successfully prepared by melt polycondensation of 1,8-octanediol and citric acid in the presence of PCL and subsequent thermocuring,and PCL was successfully connected to the elastomer network structure;the mechanical properties,hydrophilicity and degradation properties of the bioelastomers could be adjusted by the molecular weight and mass fraction of PCL and curing time;when adding 20wt% of PCL with a molecular weight of 80,000,POCL bioelastomer had relatively good,comprehensive mechanical properties and excellent tensile recovery.(2)Fiber mats with different ratio of POCL prepolymer and PCL were prepared by electrospinning.POCL fiber scaffolds were obtained after thermocuring and the effects of the ratio of POC and PCL on the properties of the fiber mats were explored.The surface morphology and properties of POCL fiber mats were characterized by SEM,DSC,DMA,etc.The following conclusions were obtained: the existence of PCL made POCL prepolymer electrospinnable;the POCL/PCL electrospun fiber mats exibited good fiber structure after long-time curing at low temperature;the mechanical properties and hydrophilicity of the fiber mats could be adjusted by the mass ratio of POCL and PCL;when the mass ratio of POCL and PCL was 63/37,the cured fiber mat had relatively good comprehensive mechanical properties.POCL/PCL fiber mats also had good biocompatibility.