Synthesis of Cationic Surface Sizing Agent and Its Application

Cationic styrene-acrylate latex as surface sizing agent had been prepared with the emulsion polymerization by use of styrene, dimethylaminoethyl methacrylate, 2-ethylhexyl acrylate, modified PVA 0588 as the emulsifiers. The infrared spectrum of copolymer and particle size and physical properties were separately determined. The results indicated that the obtained copolymer emulsion was very stable, the average molecular weight of copolymer approached about 45000 g/mol and polydispersity index was 1.6. The copolymer with higher quaternization degree had smaller particle size and narrower particle distribution when initiator had the same usage. The copolymer as surface sizing agent improved the hydrophobicity of paper, the water-proofing time approached 14.7 seconds, the copolymer with narrow particle distribution increased 7% sizing performance than the one with wide particle distribution.