PAE/CPAM WATER-IN-WATER COMPOSITE EMULSION AS A MODERN RETENTION AID OF NEUTRAL-ALKALINE PAPER SIZING WITH ACID ROSIN SIZES

摘要

The polyaminoamide-expoxy chloropropane (PAE) /the cationic polyacrylamide (CPAM) composite emulsion was prepared by water-in-water emulsion polymerization and used as the retention aid of rosin size. The dual retention aids system, consisting of this polymer and aluminum sulfate(alum) for neutral-alkaline paper sizing using acid rosin sizes, was evaluated by a series of experiments. The results indicated that the PAE/CPAM was very effective and a small amount of the polymer used together with aluminum sulfate considerably increased the size retention and sizing degree of paper under neutral-alkaline conditions, in which the acid rosin size-alum sizing is impossible and not practical. The cationic charge density of PAE/CPAM significantly influenced the sizing efficiency of the rosin sizes, and the polymer with lower charge density was more efficient than higher charge density for the emulsion rosin size. And the sizing degree and strength of paper under neutral-alkaline conditions were apparently affected by the dosage of polymer addition, both the dry tensile strength and wet tensile strength of paper were improved by the PAE/CPAM. Furthermore, the retention of alkaline filler CaCO3 was improved by the polymer addition because of its aggregation function on calcium carbonate particles. It is clear that the PAE/CPAM water-in-water composite emulsion can be used as a multifunctional additive for papermaking.