Heterogeneous nanocomposite adhesive: Experimental testing and computational multiscale modeling

This study is focused on a multiscale adhesive used for the investigation of bone bonding applications. Additionally hydroxyapatite nanoparticles were added to the adhesive to create a composite in attempts to enhance both the mechanical and biological properties. One of the main objectives was creating an adhesive system that is tailored to the biological environment in which it must operate. A solid adhesive layer as found in most engineering applications would be counterproductive to the bone healing process and thus an alternative solution was sought. A preliminary cell culture demonstrated that a polyurethane based adhesive tested was nontoxic to cells, and had the unique chemistry that would allow it to be processed into a foam. This porous structure is advantageous in a fracture healing scenario since the interconnecting pores aid in cell migration and ingrowth. This heterogeneous nanocomposite foam that is able to provide optimum conditions for the biological environment also presents additional issues that are of interest from a fundamental viewpoint. The material is composed of multiscale features with hydroxyapatite particles at the nano-scale level, and pores at the micro-scale level. This porosity and spatial heterogeneity introduces new challenges and opportunities for characterization and modeling. The experimental testing of this composite adhesive with unique characteristics then also provides support for the development of open issues in multiscale heterogeneous adhesive models