Dicyandiamide-formaldehyde polymer containing phosphonic acid groups

Dicyandiamide-formaldehyde polymer containing phosphonic acid groups

[Preparation method] The author used dicyandiamide , phosphorus trichloride , formaldehyde and inorganic ammonium as raw materials to prepare dicyandiamide-formaldehyde polymers containing phosphonic acid groups through polycondensation reaction.

①Polycondensation reaction Dissolve inorganic ammonium salt in a reactor containing fatty aldehyde and water at a reaction temperature of 10-60°C, add dicyandiamine , increase the reaction temperature to 60-95°C, and control the reaction time within 0.

②Hydrolysis reaction and esterification reaction: Reduce the temperature of the above reaction liquid to 20～70℃, add phosphorus trichloride, increase the reaction temperature to 90～120℃, react for 2～9h, and reduce the material temperature to 45～85℃ , Add additives, continue the reaction for 1 to 3 hours, and cool to room temperature to obtain the product

(1) Method one

①Polycondensation reaction: Slowly dissolve 4.

②Hydrolysis reaction and esterification reaction Lower the temperature of the above-mentioned reaction liquid to 60°C, add 15.

(2) Method two

①Polycondensation reaction: Slowly dissolve 1.

②Hydrolysis reaction and esterification reaction lower the temperature of the above-mentioned reaction liquid to 20°C, add 23.

[Application] The author has used phosphonic acid group-containing dicyandiamide formaldehyde polymer to treat printing and dyeing wastewater, and the results are shown in Table 3-31

Table 3-31 Treatment effect of printing and dyeing wastewater

The author also used phosphonic acid group-containing dicyandiamide-formaldehyde polymer (MDF) to treat pulping and bleaching wastewater, and compared the flocculation performance of different flocculants.