Influence of softwood cellulose fiber and chitosan on the film-forming properties of collagen fiber

Collagen fiber films were prepared with the addition of softwood cellulose fiber (SWCF) and chitosan (CHS). The modulus, viscosity and yield stress of collagen fiber dispersions (CFD) increased or decreased with the addition of SWCF or CHS, respectively. The addition of SWCF significantly improved the film flexibility at dry, wet state and decreased the swelling ratio of films. The addition of CHS significantly increased the tensile strength (TS) of films at different states and decreased the swelling ratio and shrinkage ratio. For the blending of the two polymers, the CHS has more improvement effect than SWCF in TS (wet, boiled), swelling ratio and shrinkage ratio. The thermodynamic properties of films were improved by adding SWCF and CHS. Optical microscope images showed that some of the SWCF could appeared on the film surface and the CHS could well dispersed in the collagen fiber network. The SEM observation indicated that the collagen fiber formed layered network and the addition of SWCF made the fiber network irregular, while the CHS made the fiber layer denser. Electrostatic interactions excited between CHS and collagen and the addition of SWCF and CHS changed the crystal diffraction patterns to a certain extent.

Automated summary

In this study, collagen fiber films were modified by the addition of SWCF and CHS, resulting in improvements in properties such as tensile strength, swelling ratio, and shrinkage ratio. The CHS had a more significant impact on the properties compared to SWCF, especially in terms of tensile strength and dimensional stability.