Dynamic Mechanical Analysis of Poly(Vinyl Alcohol)-Based Hydrogels with Boric Acid as Cross-linker

Hydrogels are materials formed from a hydrophilic polymer matrix crosslinked through physical or chemical bonds and dispersed in water. To date, these materials have been used mainly in the medical and pharmaceutical, due to the large amount of water retained that makes them highly biocompatible. The hydrogel ability to absorb water also makes them interesting in the space field for radiation shielding applications where the large hydrogen content is helpful to reduce the damage caused by ionizing radiation on astronauts and electronic devices. In this work, physically crosslinked hydrogels are made using a matrix of poly(vinyl alcohol) (PVA) with 0% and 2% of boric acid (BA). The results in terms of chemical composition from Fourier transform infrared spectroscopy (FTIR), mechanical properties from dynamic mechanical analyzer (DMA) and swelling behavior are used to assess the BA capacity to form hydrogen bonding with PVA macromolecules in the physically-crosslinked hydrogels.