Characterisation of Hyaluronic Acid Blends Modified by Poly(N-Vinylpyrrolidone)

The viscosity behaviour and physical properties of blends containing hyaluronic acid (HA) and poly(N-vinylpyrrolidone) (PVP) were studied by the viscometric technique, steady shear tests, tensile tests and infrared spectroscopy. Viscometric and rheological measurements were carried out using blends of HA/PVP with different HA weight fractions (0, 0.2, 0.5, 0.8 and 1). The polymer films and HA/PVP blend films were prepared using the solution casting method. The study of HA blends by viscometry showed that HA/PVP was miscible with the exception of the blend with high HA content. HA and its blends showed a shear-thinning flow behaviour. The non-Newtonian indices (n) of HA/PVP blends were calculated by the Ostwald-de Waele equation, indicating a shear-thinning effect in which pseudoplasticity increased with increasing HA contents. Mechanical properties, such as tensile strength and elongation at the break, were higher for HA/PVP films with w(HA) = 0.5 compared to those with higher HA contents. The elongation at the break of HA/PVP blend films displayed a pronounced increase compared to HA films. Moreover, infrared analysis confirmed the existence of interactions between HA and PVP. The blending of HA with PVP generated films with elasticity and better properties than homopolymer films.

Automated summary

The study investigated the viscosity behavior and physical properties of blends containing hyaluronic acid (HA) and poly(N-vinylpyrrolidone) (PVP) using viscometric technique, steady shear tests, tensile tests, and infrared spectroscopy. The results showed that HA/PVP blends were miscible, with a shear-thinning flow behavior and increased pseudoplasticity with higher HA contents. The mechanical properties of blends with HA weight fractions of 0.5 were superior, showing higher tensile strength and elongation at the break compared to those with higher or lower HA contents. Additionally, infrared analysis confirmed interactions between HA and PVP, generating films with elasticity and improved properties compared to homopolymer films.