Study On The Preparation, Modification And Performance Of Type I Collagen Fibers

Collagen is a kind of biomaterial with excellent biocompatibility,biodegradability and low immunogenicity,but it has the disadvantages of poor mechanical properties,poor stability in water,susceptible to thermal denaturation and high raw material cost.In this study,the dry-jet wet spinning process of regenerated collagen fibers was explored,and the properties of collagen fibers were modified by physical and chemical cross-linking methods.Collagen/carbon nanotube composite fibers and collagen/alginate composite fibers were prepared respectively with carbon nanotube and sodium alginate as reinforcing phase.By means of SEM,TEM,DSC,TG,XRD,FTIR,contact angle test and mechanical properties test,the structure and properties of collagen fibers and its composite fibers were characterized and tested.The results showed that:The tensile strength of collgen fibers prepared by dry-jet wet spinning reached 1.65 cN/dtex,which was 120.0%higher than that of wet spun fibers.The elongation at break was 17.0%,which was 88.9%higher than that of wet-spun fibers.The crystallization property and thermal stability of dry-jet wet spinning fibers were significantly enhanced In the DHT crosslinking method,the tensile stress of 15×10-2 cN/dtex was applied and the breaking strength of the crosslinked fibers for 24h under 110 ? reached 2.07 cN/dtex,which was 25.5%higher than that of the primary fiber.The breaking strength of the fibers reached 1.82 cN/dtex through UV crosslinking for 8h,which was 10.3%higher than that of the primary fibers.After physical crosslinking,the internal structure of the regenerated collagen fibers becomes denser,which sigpificantly improves their mechanical properties and thermal stability.In the fiber crosslinked by two-step in-situ crosslinking method,the breaking strength reaches 2.01 cN/dtex,which was 27.3%higher than that of the primary fibers.In addition,the rigidity of the fiber increases,and the water absorption rate decreases to about 187.0%.Moreover,the stability in water is greatly improved.Multi-wall carbon nanotubes(MWNT)were modified by cetyl trimethylammonium bromide(CTAB)to obtain stable acidic MWNT water dispersion solutions.Collagen/MWNT composite fibers were prepared by dry-wet spinning.The breaking strength of MWNT composite fibers added with an average length-diameter ratio(AR)of 4000 reached 2.60 cN/dtex,which was 57.6%higher than that of the primary collagen fibers.The diameter and length-diameter ratio of MWNT are the main factors affecting the self-assembly structure of collagen,microfiber arrangement and composite fibers performance.Collagen/alginate composite fibers with high collagen content were successfully prepared by wet spinning and two-step solidification process.Collagen molecules are tightly bounded to alginate molecules by polyelectrolytes effect The breaking strength of collagen/alginate composite fibers with a mixture ratio of 6/4 of collagen and sodium alginate was 5.9%higher than that of collagen fibers,and its thermal stability was significantly improved.