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In this study, sodium alginate/gelatine (SA/G) hydrogels were prepared to obtain wound dressing with good, moist, healing, and biocompatibility properties. The physicochemical properties of hydrogels were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy, and a swelling test. Dynamic viscoelastic properties including the storage, loss moduli, G 0 and G 00 , and loss angle, tan delta of both freshly prepared and swelled gels were examined in oscillatory experiments. Its results revealed that tested SA/G hydrogels exhibit highly elastic behavior similar to the viscoelastic response of human skin. Based on the performed analysis, it could be suggested that the SA/G hydrogel is a potential wound dressing material providing and maintaining the adequate moist environment required to prevent scab formation and the dehydration of the wound bed.

The effect of pressure and temperature on the shear and elongational deformation rateϪdependent viscosities has been experimentally investigated for several polymers (HDPE, LDPE, LLDPE, PP, PC, PMMA, and PS) on a capillary rheometer with a backpressure device. Pressure, ␤, and temperature, ␣, coefficients have been determined through simultaneous fitting of the shear and extensional viscosity data by the modified White-Metzner model. The dependence of ␤ and ␣ on temperature and pressure, respectively, was investigated and it has been found that simple relationships exist between pressure and temperature sensitivity coefficients for individual polymers.

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The relation between PVT and rheological measurements of several polymer melts including polyethylenes, polypropylene, polystyrene, poly(methyl methacrylate), and polycarbonate has been taken into investigation. Pressure-temperature dependent viscosities, determined on rotational and backpressure-modified capillary rheometers, were fitted through the Carreau-Yasuda model. PVT data was analyzed by the help of the Simha-Somcynsky equation of state (SS EOS). The thermodynamical parameters of the SS EOS were connected to constant-stress viscosity (experimental) and zero-shear viscosity (extrapolated). The Doolittle relationship was modified into the form of . The relation was employed and tested for the data evaluation. It proved to be a good tool for linearization of PVT and rheological data.