Stabilization of the emulsion of Alkenyl Succinic Anhydride (ASA) in water using cellulose nanofibrils

Abstract Alkenyl Succinic Anhydride (ASA) is sizing agent that is applied as an aqueous emulsion during the papermaking process to improve paper’s hydrophobicity. However, its application becomes difficult as the emulsion quickly destabilizes due to the coalescence phenomenon and the high reactivity of ASA with water. In this work, we used cellulose nanofibrils (CNFs) to increase the stability of the ASA emulsion over time. Small amounts of CNFs added to the emulsion helps to increase its storage life by almost 3 times, by means of stabilizing the average droplet size and reducing the amount of hydrolyzed ASA. The time extension allows higher flexibility of the sizing processes. In this work, we identify the negative impact that the temperature and the presence of metal ions in water have on the quality on the optimal ASA emulsion, resulting in a reduction in their effects for both factors with the presence of cellulose nanofibrils.