Retention behavior of alkenyl succinic anhydride size on handsheets

Abstract

Handsheets were prepared with alkenyl succinic anhydride (ASA) under various conditions, and retention behavior of ASA on the handsheets was studied. The addition of polyamideamine-epichlorohydrin resin (PAE) and/or aluminum sulfate to pulp suspensions resulted in higher sizing level together with greater ASA content of the handsheets prepared thereof, compared with the result for handsheets prepared without PAE. At the same ASA content, the handsheets prepared by the ASA-aluminum sulfate system had higher sizing level than those prepared by the ASA-PAE system. ζ-Potential measurement supported the idea that ASA emulsion particles had amphoteric surface charges in pulp suspensions, owing to hydrolyzed ASA molecules formed on size emulsion particles by hydrolysis. Cationic compounds such as PAE and aluminum sulfate can, therefore, interact with anionic sites of both ASA emulsion particles and cellulose, and higher size retention can be achieved by these electrostatic interactions in pulp suspensions.