|
|
Characterization of Mechanical Properties of semi-IPN Hydrogels Based on Poly(vinylalcohol)
Přibyl, Jiří ; Pekař, Miloslav (referee) ; Kalina, Michal (advisor)
This diploma thesis deals with the issue of mechanical properties of semi-IPN hydrogels based on poly(vinylacohol). The prepared poly(vinylalcohol) hydrogels were modified by the addition of sodium alginate, dextran, DEAE-dextran, chitosan, and poly(ethyleneglycol). The mechanical properties were studied by various methods, such as the oscillatory amplitude rheological test, dynamic mechanical analysis, swelling experiments and drying characteristics. Microcalorimetry was used to study the interactions between poly(vinylalcohol) and biopolymers in solution using the ITC method and the morphology of prepared hydrogels was visualized using cryo-SEM. The main concept for semi-IPN hydrogels is that there is minimal influence on the mechanical properties but leads to the modification of the binding sites present in the hydrogel structure, which has a high potential in transport properties. From the experimental results, the effects of each biopolymer on the mechanical properties were determined. The obtained results showed that the additions of biopolymers do not have a significant impact on the mechanical properties of PVAl hydrogels, but in the case of swelling experiments, there is a significant influence of the number of freezing/thawing cycles, ionic strength of the environment, and the used biopolymer.
|
guest ::
RSS feed.