Preparation And Properties Of Type Ⅰ Collagen - Based Biogenic Fibers

Type I collagen from Nutria tail tendons was selected as a research object in this thesis. We isolated type I collagen from nutria tail tendons used enzymatic method. Collagen fibers were obtained by wet spinning, and the fibers were modified by cross-linking and blending. The structure and properties of the collagen and collagen fibers were investigated by FTIR, UV, SEM, TG, XRD and tensile testing.These collagens isolated from nutria tail tendons appeared to be loose, fibrous and porous structure under SEM. UV-Vis spectra showed that the collagen had a high purity. SDS-PAGE pattern and amino acid profile confirmed that extracted collagen was mainly composed of type I collagen. FTIR results confirmed that the collagen triple helical structure was preserved. Denaturation temperature (Td) and maximum transition temperature (Tm) values were 37.0 and 51.1℃, respectively.The collagen fibers were cross-linked by glutaraldehyde vapor. The results showed that the tensile strength of the collagen fibers can be elevated efficiently. The tensile strength of the collagen fibers with 20 min crosslinking can be improved by 15.8% compared with that of the neat collagen fibers. At the same time, the water absorption of the collagen fibers was significantly reduced at 20 min and then stay unchanged. Furthermore, the stability of triple helix and thermal stability of collagen fibers were improved. FTIR results showed that chemical reactions occurred between the collagen fibers and glutaraldehyde.The collagen/chitosan composite fibers were prepared by wet spinning technique. The results showed that good compatibility and interactions were observed between collagen and chitosan in the appropriate blending ratio range, in which the optimal ratio of collagen/chitosan was 8:2 (w/w). Compared with the collagen fibers, the mechanical properties of the composite fibers were increased by 30%. The composite fibers had better spinning ability compared with the neat collagen fibers. The cross-sections of the collagen/chitosan composite fibers were denser and the surfaces were smoother. The DSC, XRD and FTIR results also demonstrated that there exists interactions between collagen and chitosan in the composite fibers, which change with the change of blending ratio range.