The Study On Synthesis And Characterization Of Gelatin Grafting PCL

In recent years biological materials in the biomedical fields have been widelyused, poly(ε-caprolactone)(PCL) as a kind of biodegradable and biomedical material,has been focused on because of its great potential applications. Gelatin as a naturalpolymer biomedical material has unique performance in a range of areas such asbiocompatibility and biodegradability. However, due to the existence of variousstructural characteristics these materials, such as gelatin and PCL which has beendeveloped itself are difficult to satisfy new biomaterials’ needs, so we develop a moreapplicable to the human body gelatin grafting PCL copolymer to make up andovercome the shortcomings of individual PCL or gelatin material. Now based onprevious research this paper make a further study of synthesis and properties of thegelatin and PCL, which are hoped to be more suitable for the application of gelatin tomeet the requirements of practical application.In this paper, molecular weight of5000,9000,14000PCL was first synthesizedby ring-opening polymerization of ε-caprolactone with n-butyl alcohol as initiator,stannous octoate as catalyst. In the preparation of PCL, some factors will affect themolecular weight of PCL such as reaction time, reaction temperature, the purity ofmonomer were investigated. In order to graft Gelatin with PCL, PCL with hydroxylend group was reacted with IPDI to generate PCL with isocyanate functional group(PCL-NCO). Then PCL-NCO reacted with the hydroxyl/amino groups of gelatin inhomogeneous system and yielded the modified gelatin/degraded gelatin copolymers.The grafted copolymers were characterized by means of1H-NMR, FTIR whichindicated the conjugation of PCL onto gelatin chains; the thermol properties andcrystallinity was discussed by the results of DSC and XRD, modified gelatinsegments retained the crystallinity of PCL; the more of PCL content, the less ofgelatin grafting PCL on volumetric swelling degree, dissolution ratio, waterabsorptionand water retention rate in PBS solution. Gelatin, PCLand gelatin graftingPCL were kept in PBS solution to test degradation rate, gelatin graft PCL show lowerdegradationrate than gelatin, and decrease with increasing molar ratio ofPCL/gelatin.