Preparation and application of oxidized acetyl cyanoethylated starch as surface sizing agent

The oxidized acetyl cyanoethylated starch was synthesized with oxidized corn starch, vinyl acetate and acrylonitrile in alkaline medium when the pH was 9, the reaction temperature was 30°C and the ratio of vinyl acetate to acrylonitrile was 1:2 to 2:1. The characteristic of the modified starch was analyzed with FT-IR, SEM. Comparing the surface sizing results of oxidized starch and the modified starch, it was found that the oxidized acetyl cyanoethylated starch with lower substitution degree was a more effective surface sizing agent compared with either the oxidized acetyl starch or the oxidized cyanoethylated starch. The surface strength, smoothness, folding endurance and tensile strength of the paper can be improved by surface sizing with the oxidized acetyl cyanoethylated starch.