Cellulose nanocrystals obtained from cynara cardunculus and their application in the paper industry

Biorefinery aims at designing new virtuous and high-efficiency energy chains, achieving the combined production of biofuels (e.g. bioethanol) and biobased products obtained from by-products and residues. This contribution will present the lab experience carried out by the Italian Biomass Research Centre (CRB Section of CIRIAF) in extracting cellulose nano-crystals (NCC) from a pre-treated (via Steam Explosion) fraction of cynara cardunculus. This is a very common, abundant residual and invasive arboreal variety in central Italy. A parallel ongoing experimental programme is focused on producing bioethanol from some rurally available ligno-cellulosic matrices [1]. The NCC extraction methodology consists of a five step protocol allowing the separation of the crystalline content of cellulose. Such a procedure is literary captured [2-4] with the exception of one step in which the conditions have been optimized by CRB Lab. This procedure has been applied for the production of NCC from residual biomass (i.e. cynara cardunculus) pretreated by steam explosion and from microcrystalline cellulose (MCC). The presented contribution will discuss some of the initial results achieved using the obtained nanocrystals as reinforcing filler in a common paper sheet; it was found that the tensile strength module increased from 3.69 kg/(15 mm) to 3.98 kg/(15 mm), the durability behavior (measured by bending number) changed from the value 95 to the value 141, and the barrier properties (measured by Gurley porosity) were improved passing from 38 s to 45 s.