A comprehensive study on nanocelluloses in papermaking: the influence of common additives on filler retention and paper strength

Nanocelluloses are being explored and produced at an impressively increasing pace. Due to their good characteristics as reinforcement agent, their application in the most diverse fields has proven to be very beneficial. Their use in papermaking has been investigated in several studies, but the industrial implementation is still in a preliminary stage. In the present study, the influence of nanocelluloses, produced by four different treatments (mechanical, enzymatic hydrolysis, TEMPO-mediated oxidation and carboxymethylation) in the properties of filler-containing laboratory handsheets was assessed. Furthermore, five series produced with different additives, among internal strength and sizing agents as well as a retention agent, allowed to investigate the interactions between the common additives used in paper production and nanocelluloses. It was found that the different properties of the studied nanocelluloses led to very different interactions with the paper components. In this sense, by properly selecting the furnish to use (in terms of nanocellulose typology and presence or absence of each additive), high improvements of filler retention and dry and wet--web strength, as well as reduced surface roughness and water penetration, could be achieved.