Application of Cationic Starch with High Degree of Substitution in Packaging Paper from High Yield Pulp

In this paper the cationic starch with high degree of substitution (HCS) is prepared with NaOH as alkali catalyst and 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CTA) as cationic reagent by using the semi-dry process. Then the prepared cationic starch with high degree of substitution is used to improve the properties of packaging paper from high yield pulp. The results show that the degree of substitution of cationic starch increases firstly and then decreases after reaching the peak value with the increase of alkali catalyst content, cationic reagent, reaction temperature, reaction time and water content in the reaction system. The proper preparation condition of HCS: water content is 30%, CTA/AGU is 1.0 (the mol ratio of CTA to unit glucose), NaOH/CTA is 1.2 (the mol ratio of NaOH to CTA ), the reaction temperature is 65℃, the reaction time is 4h. Cationic starch with different degrees of substitution can increase retention and strength properties of paper. HCS can improve basis weight and strength properties of paper. When the cationic starch with degree of substitution 0.64 is used and its dosage is 0.6%~ 0.8%, the increase effect of strength properties of paper is the best.