Browsing by Subject "Physical Crosslinking"

A polyoxazine based reversibly crosslinking hydrogel material developed for MEW was modified to increase its resistance to thermal degradation and impart control over its swelling properties. A portion of side chain functionalized Diels-Alder crosslinking moieties was replaced by hydrophobic octyl groups to induce the formation of a dual network hydrogel of equal crosslink density upon swelling. This modification was found to have no negative effects on the processing behavior of the material and was able to produce MEW printed scaffolds with equal stacking accuracy and fiber shape fidelity at processing temperatures 20˚C lower than a fully chemically crosslinked material. The thermal degradation of this dual network crosslinked material was significantly reduced, showing minuscule increases in viscosity when held at processing temperatures for several hours. The swelling of the dual network hydrogel was found to be similar to that of fully chemically crosslinked hydrogels despite consisting of significantly fewer chemical crosslinks, demonstrating another potential avenue of control over this material property. Finally, promising alterations in mechanical properties were observed in the dual-network hydrogel versus chemically crosslinked hydrogels, along with observations of water induced crystallization attributed to the octyl chains.