Preparation And Performance Of Silk Fibroin-carbon Nanotubes/Poly (?-caprolactone) Shape Memory Composites

Chemically crosslinked poly(?-caprolactone)(c-PCL)shape memory material exhibits good biocompatibility and biodegradability while peforms poor mechanical property,which limits cPCL applied in bio-medical field.In this study,c-PCL was chosen as the matrix material,powder silk fibroin(SF)and SF-functionalized carbon nanotubes(SF-M)as the reinforcement materials to prepare c-PCL based shape memory composite materials by solvent method and hot compression molding and how they affected the mechanical and shape memory properties of cPCL based shape memory composite materials was explored.Firstly,SF/c-PCL shape memory composite materials were prepared by solvent method and hot compression molding with c-PCL as the matrix material and power SF as the reinforcement material,and that how SF modification affected the morphology and structure,mechanical property and shape memory property of those shape memory composites was studied.The results showed that SF had some effects on interfacial adhesion between SF and c-PCL,while SF was under 15wt%,the composites performed good interfacial adhesion;then the composite showed good mechanical property that young's modulus was up to 82.16 MPa when SF accounted for 5wt%,which also acted excellent and stable shape memory property that shape memory fixity rate and recovery rate were up to 94.88% and 90.37%.Secondly,carbon nanotubes(CNTs)which own great mechanical property were selected as the reinforcement material to gain better mechanical property of the composites.In order to improve the disperslbility and obtain favorable biocompatibility of the CNTs,SF was chosen to chemically modify the CNTs,and that how chemical modification made effects on morphology and structure,dispersion and cytotoxicity was investigated.SF grafting on the surface of CNTs was proved by transmission electron microscope(TEM),FTIR and X-ray photoelectron spectroscopy(XPS)analysis.Dispersion and cytotoxicity analysis showed that SF-M performed promoted disperslbility and biocompatibility.Lastly,SF-M was used as enhancement material to prepare SF-M/c-PCL shape memory composite materials by solvent method and hot compression molding.That how SF affected the morphology and structure,mechanical property and shape memory property of those shape memory composites was studied.The results showed that SF-M performed good interfacial adhesion with c-PCL;compared with pure c-PCL material,the mechanical property of SF-M/cPCL composites was promoted remarkably that when SF-M only accounted for 0.1wt%,young's modulus and tensile strength were increased by 20 MPa and 1.22 MPa and its shape memory property kept stable that shape memory fixity rate and recovery rate were 87.82% and 86.52% when SF-M accounted for 0.1wt% of the composite.