Cellulose Nanocrystals Obtained from <i>Cynara Cardunculus</i> 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. This emerging philosophy can represent an important opportunity for the industrial world, exploiting a new kind of nano-smart biomaterials in their production chains. This paper will present the lab experience carried out by the Biomass Research Centre (CRB) in extracting cellulose nanocrystals (NCC) from a pretreated (<i>via Steam Explosion</i>) fraction of <i>Cynara cardunculus</i>. This is a very common and invasive arboreal variety in central Italy. The NCC extraction methodology allows the separation of the crystalline content of cellulose. Such a procedure has been considered in the literature with the exception of one step in<i> </i>which the conditions have been optimized by CRB Lab. This procedure has been applied for the production of NCC from both <i>Cynara cardunculus</i> and microcrystalline cellulose (MCC). The paper will discuss some of the results achieved using the obtained nanocrystals as reinforcing filler in a paper sheet; it was found that the tensile strength 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, increasing from 38 s to 45 s.