Mid Sweden University

This paper deals with the production of reinforced and highly porous cellulose/nanocellulosebased foams with excellent mechanical properties, aiming to replace fossil based materials for barrier against air, water and thermal insulation. A lab concept has been developed to produce porous solid foams via convective drying of wet foams. The ambition has been to produce solid foams of low density, in the same regions as expandable polystyrene (EPS) and polypropylene (EPP). Foams have been produced by varying the pulp fiber source and by varying the added amount of foaming agent and stabilizing/reinforcement agents. The wet foams have been characterized by the foam ability, foam stability, drainage capacity and drying behavior. The dried solid foams have been characterized both mechanically and structurally but also with respect to barrier properties and thermal insulation.

The results demonstrate that cellulosic foams reinforced with cellulosic nanocrystals can be produced with superior foam stability and excellent mechanical properties, in densities similar to foamed materials based on EPS and EPP. The choice of pulp fiber and reinforcement agent, along with the foaming technology, is decisive for the foam stability, processability and mechanical properties of the solid foam. During the presentation, our experience on this will be highlighted.