The present disclosure provides for a method of preparing and using an emulsion for treating a papermaking process. The emulsion is an oil-in-water emulsion of alkenyl succinic anhydride emulsified with a polymer comprising at least one primary or secondary amine containing monomer. The method comprises adding an oil-in-water emulsion to the papermaking process; wherein the oil-in-water emulsion comprises alkenyl succinic anhydride emulsified with a polymer comprising at least one primary or secondary amine containing monomer; and wherein the oil-in-water emulsion is added in an amount sufficient to improve sizing of the paper produced by the papermaking process. The primary or secondary amine may be a secondary amine comprising diallylamine, and the polymer may be a diallylamine-acrylamide copolymer.