A Comprehensive Study on the Rheological Properties of Collagen/PVA Spinning Solutions from Acetic Acid Solvent

Collagen and polyvinylalcohol (PVA) are extremely important in the applications of biomaterials including with electrospinning and wet-spinning methods. However, the rheological behavior of collagen and PVA blended solutions before spinning is still scarce. In this work, collagen was firstly extracted from pigskin building on the maximum maintenance of the natural structure and blended with PVA. The following detailed investigation on the viscosity and the rheology of blended solutions were carried out by rotate rheometer. The obtained results suggested that collagen/PVA solutions performed as Non-Newtonian fluids. Significantly, all the samples showed the shear thinning pseudoplastic behaviors with the steady shear rate. With increasing the collagen content or decreasing the operating temperature, the viscosity of blended solutions both increased at the same shear rate of 16.8 s−1, accompanied by the fall of the Non-Newtonian index (n) for the collagen/PVA samples. Furthermore, both low temperature and high concentration increased the structure of the spinning solution, which indicated that the temperature should be controlled in a higher range to improve the spinnability of the solution, but without collagen decomposition in the whole process. The increase of PVA content could reduce the degree of system structure, that was to say that the addition of PVA improved the spinnability of the system. As an application, the solution of collagen/PVA was wet spinned with the ethanol absolute as coagulant and collagen/PVA composite fibers were successfully prepared, which have compensated for the disadvantage of mono-component collagen materials. Of course, this experimental results is not limited to the above application, which really extends the potential use of collagen/PVA blended solutions towards the design of the collagenbased biomaterials.