Polyacrylamide anions and cations are significantly different in a number of ways, as follows:
Cationic polyacrylamide and anionic polyacrylamide are very different in the production of raw materials and production process, the main raw materials of anionic products are acrylamide, acrylic acid, sodium hydroxide, pure water, dispersants, initiators, etc. The main raw materials for the production of cationic polyacrylamide are acrylamide, DAC DMC, pure water, dispersants, initiators, etc. In addition to this, there are the following differences:
Appearance: While both have white granular and emulsion forms, the color of the emulsion is different. Anionic polyacrylamide emulsions are typically white in color, while cationic polyacrylamide emulsions have a slight bluish tinge. Polyacrylamide in solid form, both anionic and cationic types are small white or yellowish particles in appearance, which are generally difficult to distinguish with the naked eye.
Molecular weight: The molecular weight of anionic polyacrylamide usually ranges from 4 million to 35 million, while the molecular weight of cationic polyacrylamide is generally between 7 million and 12 million, and there are also products with a molecular weight of about 15 million. In general, the anionic form has a higher molecular weight.
Index: The main indicators of anionic polyacrylamide are molecular weight and degree of hydrolysis (the latest national standard GB T 17514-2017 water treatment agent anionic and nonionic polyacrylamide national standard national standard national standard defines the degree of hydrolysis as anionic degree), while the main indicators of cationic polyacrylamide are cationic degree and molecular weight. These indicators have an important impact on the performance and application of different types of polyacrylamide.
Uses: The two are also different in the field of application. Anionic polyacrylamide is mainly used as a flocculant, suitable for the treatment of inorganic wastewater with coarse suspended particles and high concentration, such as coal mine wastewater, sand washing wastewater, etc., and can also be used in the petroleum industry, textile sizing agent, paper industry and as a binder. The cationic polyacrylamide is mainly used to treat organic wastewater, such as food factories, sugar factories, municipal sewage, etc., and its flocculation effect is usually several times or dozens of times that of anionic polyacrylamide or nonionic polyacrylamide. In addition, cationic polyacrylamide is also more used in sludge dewatering, which has the characteristics of fast floc formation speed, coarse floc, extrusion resistance, and good shear resistance.
*: Generally speaking, cationic polyacrylamide will be more expensive than anionic polyacrylamide. This is mainly due to the relatively complex and costly production process of the cationic type. At the same time, whether it is anionic or cationic, the higher the molecular weight or ionic content, the higher the ** will be.
Structural properties: cationic polyacrylamide is a linear polymer compound with a variety of active groups, which can affinity and adsorption with many substances to form hydrogen bonds, mainly flocculation of negatively charged colloids. The anionic polyacrylamide is a water-soluble polymer, and its molecular chain contains a certain number of polar groups, which can bridge the particles by adsorbing the solid particles suspended in the water, or condense the particles to form large flocs through charge neutralization, thereby accelerating the sedimentation of the particles in the suspension.
In general, there are obvious differences between polyacrylamide anions and cations in terms of appearance, molecular weight, index, use, ** and structural properties. These differences make them have their own advantages and applicability in different application areas.