The cationic degree of cationic polyacrylamide (CPAM) refers to the percentage of ionization of amino groups (NH2) or amino groups (NR2) in CPAM molecules. The determination method generally adopts the iodometric titration method, and the specific steps are as follows:
Take a sample of a certain quality, and adjust the pH value to between 4-6 with deionized water or hydrochloric acid.
Add potassium iodide solution, and potassium iodide reacts with amino groups or amino groups in CPAM to generate iodide.
Titrate the remaining potassium iodide with sodium sulfite solution, and sodium sulfite reduces potassium iodide to iodide ion.
When the solution is yellow, add starch indicator and continue titrating until the solution becomes colorless.
To calculate the percentage of cationization degree, the formula is:
Cationization % = (titration amount - control amount) / sample mass × 1.6 × 100
Among them, the titration amount refers to the amount of sodium sulfite solution required for titration until the solution changes color, and the reference amount refers to the titration amount of deionized water or hydrochloric acid under the same conditions. 1.6 is the equivalent ratio of amino or amine reacting with iodine to generate iodide.
