Retention and drainage performance of star-shape cationic polyacrylamide

The star-shape cationic polyacrylamide (S-CPAM), initiated by pentaerythritol (PETL)/ceric ammonium nitrate, was synthesized through free radical copolymerization of AM and DMC in aqueous solution using PETL as a core molecule. The retention and drainage performances of S-CPAM were investigated using DDJ and spectrophotometer. The optimum preparation conditions of S-CPAM used as retention aid for bleached straw pulp were as follows; reaction temperature 30°C, reaction time 6 h, C (AM) = 1.721 mol/L, C (DMC) = 0.486 mol/L, C (PETL) = 1.81 mmol/L, and C (Ce4+) = 7.24 mol/L. The effects of dosage of S-CPAM, shearing, and pH Valne on performance of S-CPAM were also investigated. The results showed that the S-CPAM can improver fines and fillers retention and is relatively insensitive to shearing and pH value.