Preparation And Properties Of Polymer-hectorite Hydrogel

As a novel polymer materials, hydrogel with environmental responsiveness, water absorption, self-healing, antimicrobial, biocompatibility and so on, have been applied extensively in the medicine & biomedical, catalysts, sensors, controlled drug release, and other fields. However, conventional chemical cross-linked polymeric hydrogels are usually mechanically weak, limiting their applications to some extent. In recent years, improving the mechanical properties of the hydrogel and expanding the functionality of the intelligent hydrogel have become a hot issue in the scientific community. In this paper, we prepared toughness hydrogels based on nanocomposite hydrogels, which used hectorite as a multifunctional crosslinking agent. The main work is as follows:1. We fabricated the PAAm microgels using inverse emulsion polymerization initiated by UV light. Then the as-prepared microgels were embedded into PAAm/ hectorite hydrogels in order to form a double network in the microgels. The resulting hydrogels showed superb mechanical strength compared with those PAAm/hectorite hydrogels with no microgels. Thereafter, we examined the effects of hydrogel reactants such as the contents of microgels, physical crosslinker(hectorite), chemical crosslinker(MBAA) on the mechanical behavior of the hydrogels. Furthermore, the swelling behaviors of the hydrogels with different microgel contents were also studied.2. We engineered acrylic component into a physically crosslinked network(crosslinked by hectorite) to form Nanocomposite hydrogels(NC hydrogels). The NC hydrogel cross-linked by hectorite was the first network,The ionic coordination between Fe3+ and acrylic group was chosen as the secondary crosslink to further strengthen the NC hydrogel. At last, a immersing process in ultrapure water was applied to allow formation of more tridentate coordinates between Fe3+ and acrylic group, and an optimal dual-crosslinked and physical hydrogel was achieved that possesses ultrahigh tensile strength、large elongation、ultrahigh toughness、good self-recovery property.