Study On PPDO Catalytic Reaction And Properties

Objective:Poly(p-dioxanone)(PPDO)is a kind of aliphatic polyester with good biocompatibility,bioabsorbability and biodegradability.The unique ether bond in the molecular chain makes it flexible and is an ideal surgical suture material.It can also be used to make bone plates and tissue repair materials.The application of amphiphilic block copolymers in hydrogels,microspheres,nanospheres and micelles has attracted much attention.Poly(p-dioxanone)is an aliphatic polyether ester with excellent biocompatibility and biodegradability.It has been approved by the Food and Drug Administration(FDA)for use in humans.PPDO has relatively good comprehensive properties.Because of its unique ether bonds in the molecular chain,PPDO has good flexibility in the molecular chain,excellent flexibility,tensile strength,bonding strength,and high strength retention rate in the degradation process.PPDO has been successfully used in the manufacture of surgical sutures,bone plates and tissue repair materials,such as screws and hooks.Surgical instruments such as tablets and forceps.However,the strong hydrophobicity of PPDO greatly limits its application in drug controlled release materials.Organic alcohols can improve the degree of polymerization of PPDO.Therefore,this study intends to explore the catalytic reaction and PPDO properties under the condition of organic alcohols.Methods:The polymerization of PPDO was observed by GPC and intrinsic viscosity measurement.Results:1.Results of GPC test show that organic alcohol can obviously increase the mole cular weight of PPDO,and the result of glycerol is better than polyethylene glycol;2.The organic alcohol can improve the molecular weight of PPDO while changi ng the physical properties of PPDO.Where,glycerol can obviously improve the fractu re strength of PPDO,while the polyethylene glycol can obviously improve the flexibil ity of PPDO.Conclusions:The results of yield showed that glycerol was more effective and stable as end-sealing agent than PEG400,and the molecular weight of the product was significantly larger than that of PEG400.Add catalyst Ⅱ(PEG400 or glycerin)relative to the pure Ⅰ catalytic polymerization,can effectively make the molecular weight of polymer increases,and glycerin is PEG400 sealing and can more effectively improve the performance of the product.PEG end sealing can obviously improve the flexibility of the product,glycerin end sealing can obviously enhance the mechanical properties of the product.Considering the water content of the product,non-hydrophilic alcohols can be used to seal the end.If glycerol is used as the end-sealing agent,the ratio of catalyst and the effective discharge method for high viscosity products should be studied in detail,and the yield should be taken as an important index.As PEG is used as the end-sealing agent,young’s modulus data of the product should be obtained by increasing the ratio of end-sealing agent.