Mechanical properties of materials made of nano-cellulose

Sammanfattning: Recent experimental findings have demonstrated great mechanical properties of nanopaper compared to ordinary paper. In this work, we have studied the formation of the elastic modulus of paper. Our goal was to investigate the contribution of fibers, fiber bonds and network structure. A 2D finite element network model was developed to study the elastic properties of nanopaper. The model can handle very dense networks of large sizes. Networks were composed of bonded, curved and randomly oriented fibers. The fiber interaction was modeled with a bonding contact. The numerical analysis was compared with theoretical models available in the literature and experimental measurements. Analysis showed that the fiber stiffness, density and the aspect ratio are the most influential parameters of those investigated with dense isotropic networks. The bond activation and fiber curl affect the modulus only in relatively sparse networks.