CDD : Développement de Mousses Solides en continu à base de nanocellulose haute concentration

Foams made from cellulose fibers are biobased, high-performance and innovative solutions offering alternatives to petrochemical-based foams such as polystyrene and polyurethane. Most of the existing cellulosic foams manufacturing processes, are discontinuous and do not allow control of the air content incorporated [1]. Moreover, it has been shown that the presence of nanocellulose in cellulosic foams improves drying dynamics and mechanical properties[2]. This is why the Moustache project aims to develop new continuous manufacturing processes with controlled air content, in order to produce competitive cellulose foams with high-concentration nanocellulose. This project has 4 main focuses (figure 1). Firstly, the choice of cellulosic materials as well as potential pre-treatments of these fibers, then high-concentration nanocelluloses and possible additives. Next, the continuous air-controlled manufacturing process, where two strategies are investigated. One foaming process which produces liquid cellulosic foams. And a second foaming process which produces dried foams. Extensive work has been carried out to assess the compatibility of different cellulosic fibers with the processes. The drying of the resulting foams is of prime importance in the overall consideration of the continuous process. To this end, convective and infrared drying are explored. Finally, characterizations of the products obtained, by imaging, 3-point bending, density, bubble size in the liquid foam, etc., are carried out, with the aim of getting as close as possible to commercial petro-sourced foams.

Figure 1: Graphical abstract of the project

Reference:

[1] T. Hjelt et al. ‘Foam forming of fiber products: a review’, J. Dispers. Sci. Technol., vol. 43, no. 10, pp. 1462– 1497, Aug. 2022, doi: 10.1080/01932691.2020.1869035.

[2] A. J. Svagan et al. ‘Biomimetic Foams of High Mechanical Performance Based on Nanostructured Cell Walls Reinforced by Native Cellulose Nanofibrils’, Adv. Mater., vol. 20, no. 7, pp. 1263–1269, Apr. 2008, doi: 10.1002/adma.200701215.