Flocculants are widely used in water treatment. They are synthetic polyacrylamide series products, mainly divided into anionic, cationic, nonionic and zwitterionic. Polyacrylamide (polyacrylamide), often abbreviated as PAM, various PAM used in water treatment, in essence, a certain proportion of acrylamide and sodium acrylate through the copolymerization of polymer products, there are a series The product.
Polyacrylamide can be divided into ultra-high relative molecular weight polyacrylamide, high relative molecular weight polyacrylamide, medium relative molecular weight polyacrylamide and low relative molecular weight polyacrylamide according to its molecular weight. Ultra-high relative molecular weight polyacrylamide is mainly used for tertiary oil recovery in oil fields. High relative molecular weight polyacrylamide is mainly used as flocculant, medium relative molecular weight polyacrylamide is mainly used as dry strength agent for paper, and low relative molecular weight polyacrylamide is mainly used Make a dispersant.
Polyacrylamide is a high molecular polymer. Specializing in the treatment of various difficult-to-treat wastewater and the treatment of sludge dewatering. (Sludge dewatering generally uses cationic polyacrylamide) It is widely used in municipal sewage and sludge treatment in the paper-making printing and dyeing industry.
The molecular formula of acrylamide is: CH2 = CH－CONH2
The molecular formula of sodium acrylate is: CH2 = CH-COONa
Non-ionic organic polymer flocculant
Non-ionic organic polymer flocculants are mainly polyacrylamide. It is obtained by polymerization of acrylamide.
Anionic organic polymer flocculant
Polymers such as polyacrylic acid, sodium polyacrylate, calcium polyacrylate, and alkali hydrolyzate of polyacrylamide.
Copolymers of styrene sulfonate, lignosulfonate, acrylic acid, methacrylic acid, etc.
Cationic organic polymer flocculant
Quaternized polyacrylamide cations are all obtained by methylolation and quaternization of -NH2, which can be divided into polyacrylamide cationization and cationization acrylamide polymerization.
Polyacrylamide (PAM) first reacts with aqueous formaldehyde solution to partially methylolate the amide group, then reacts with a secondary amine for alkylamidation, and then reacts with hydrochloric acid or an aminating reagent to quaternize the tertiary amine.
Under alkaline conditions, acrylamide reacts with aqueous formaldehyde solution first, then reacts with dimethylamine, and after cooling, it is quaternized with hydrochloric acid. The product is concentrated by evaporation and filtered to obtain a quaternized acrylamide monomer.
Cationic derivatives of polyacrylamide
Most of these products are obtained by the copolymerization of acrylamide and cationic monomers.
Amphoteric polyacrylamide polymer
Partially hydrolyzed polyacrylamide is added with appropriate amount of formaldehyde and dimethylamine, and an amphoteric polyacrylamide flocculant with carboxyl group and aminomethyl group is synthesized through Mannitz reaction.
Acrylamide graft copolymer
Because starch has a rich source of cheap prices, it is also a polymer compound. It has a hydrophilic rigid chain. With this rigid chain as the skeleton, it is connected with flexible polyacrylamide branched chains. This kind of rigid and flexible network macromolecules can not only maintain In addition to the functions of the original polyacrylamide, it also has some more excellent properties.