Cationic polyacrylamide is the fastest-growing varieties in recent years, its annual growth rate in the Western developed countries 5 to 10 percent, accounted for more than 60% of polypropylene production of acrylamide. The situation in China is rather special, anionic polyacrylamide APAM accounted for over 90 % of total production , mainly for oil exploration, production of cationic polyacrylamide small and very small -scale producers , hardly formed a certain scale of production equipment. With the rapid development of the water treatment industry, the demand for cationic polyacrylamide amide rapid growth, I believe that the domestic cationic polyacrylamide in recent years will have a larger development.
Cationic polyacrylamide CPAM includes the following three types: low molecular weight polyamines, acrylamide with a cationic monomer and non- ionic polyacrylamide modified class. Polyamines include polyethyleneimine, polyethylene imidazolines, and amine - epichlorohydrin condensate and improve products, but these products are low molecular weight high charge density, mainly for functional additives, paper, and oil exploration and cosmetics industries, rarely used in sludge dewatering. Acrylamide and a cationic monomer cationic polymer yield the largest class , mainly refers to cationic monomer ( meth ) acryloyloxyethyl trimethyl ammonium chloride (DMC) and dimethyl diallyl ammonium chloride ( DMDAC), where P (AM-DMC) products of high molecular weight , adjustable from 0 to 100% cationic degree , cationic polyacrylamide powder , almost all belong to such a structure , for sludge dewatering of powdered cationic poly acrylamide also belong to this category , product molecular weight of 400 to 6,000,000 , cationic degree of 30 to 50 percent , its main problem is that the DMC need to import expensive, resulting in higher production costs. For P (AM-DMDAC), since the steric hindrance DMDAC monomer, the polymerization activity is poor, and the molecular weight is difficult to prepare cationic degree satisfactory products, so much for the dewatering of sludge, and DMDAC highly absorbent, these products usually liquid.
Nonionic polyacrylamide can be reacted with an amide group more reagents, wherein the reaction of dimethylamine and formaldehyde to generate a tertiary amine structure of the polymer, and further quaternary ammonium salts form a quaternary amine. Since the viscosity of an aqueous polyacrylamide solution is very large, typically 600 to 8,000,000 molecular weight concentration of 2% is already very viscous and difficult to which the reaction solution , the PAM low concentrations of lead cations , and usually no more than 10% higher residual formaldehyde concentration . For the organic matter content of the sludge is not high in terms of the county sewage treatment plant, low-cost non-ionic denaturing polyacrylamide Mannich product is applicable.