(180h) Rheological and Adhesive Properties of Poly(acrylic acid)/Clay Nanocomposite Hydrogels As Biocompatible Adhesive

Biocompatible nanocomposite hydrogels (NC gels) consisting of poly(acrylic acid) (PAA) and nano-sized clay (Laponite) have been synthesized by in-situ free radical polymerization of acrylic acid (AA) in the aqueous solution of Laponite. The obtained NC gels were uniform and transparent at a wide ratio of the Laponite/monomer. Effects of crosslinker and monomer content as well as neutralization degree of acrylic acid on the properties of the NC gels were characterized by rheological method. The viscosity, storage modulus G’ and loss modulus G’’ of the NC gels increased significantly upon increasing the content of Laponite and acrylic acid, but exhibited a maximum with increasing pH values and thus the neutralization degree of acrylic acid. Furthermore, these NC gels show a strong and tunable adhesion as determined by 180?a peel strength measurement. JKR test has been used to quantify the adhesive behavior of the NC gels with the confined bulk losses due to the less crack zone. It is showed that the relationship between load and displacement is sensitive to the amount of AA monomer and Laponite, which indicates the relationship between rheological properties and adhesion of the NC gels, and the important insight for the tunable adhesion of the NC gels for application such as bioadhesives.