Rheological Properties of Collagen/Hydroxypropyl Methylcellulose (COL/HPMC) Blended Solutions

Collagen/HPMC blends with different HPMC content (HC) were investigated by dynamic responses, creep recovery, thixotropy, and morphological observation. Storage modulus, loss modulus, complex viscosity, and activation energy decreased with the increased HC, while the flow behavior index increased with the increased HC and the dynamic denaturation temperature reached the maximum as HC increased to 50%, indicating that the flowability and thermal stability of collagen solution were improved by the addition of HPMC. However, the blends with higher HC tended to have a relatively lower recovery capacity, and the hysteresis loop areas of the blends were lower than that of collagen (especially when HC>50%). Additionally, the morphology of collagen/HPMC was examined by both of atomic force microscopy and scanning electron microscopy. By combining with these results, it seemed that the rheological and structural properties of collagen/HPMC were related to the hydrogen-bond interaction and compatibility between collagen and HPMC molecules. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40042.