The acrylamide produced by the hydrolysis method has a random distribution of acrylate chain segments on the polymer chain, and its percentage of moles of hydrolysis is the degree of hydrolysis among all chain lengths of the polymer chain. Compared with copolymerization, the water-soluble dander factor (HD) produced by the general hydrolysis method is not high, less than 30%. The product with HD greater than 70% theoretically should be prepared by copolymerization. This method has certain requirements for hydrolysis temperature and time, and polymer degradation is prone to occur during hydrolysis.
Aqueous solution polymerization is a polymerization reaction in which the monomer and initiator are dissolved in water. This method is simple, causes minimal environmental pollution, and has a high polymer yield. It is the earliest method used in industrial production of organic chemical compounds polyacrylamide, and has been the main method for industrial production of polyacrylamide. Research on aqueous solution polymerization has been quite in-depth.
Before inverse emulsion polymerization and inverse suspension polymerization, it is necessary to prepare a reverse colloidal dispersion system, and the monomer aqueous solution is dispersed or emulsified in the oil phase with stirring, forming a water/oil immiscible dispersion system, and then an initiator is added to initiate free radical polymerization. In general, oil-soluble initiators are used for inverse emulsion polymerization, which are mostly anionic free radical initiators and nonionic free radical initiators, while non-aqueous soluble initiators such as persulfates are mostly used in inverse suspension polymerization. There are two views on the nucleation mechanism of AM/AA inverse emulsion polymerization: micellar nucleation and monomer droplet nucleation. Its kinetics are quite different from typical positive emulsion polymerization kinetics.
Reverse suspension polymerization is an ideal method for industrial production of water-soluble polymers developed in the past 10 years. In 1982, the mechanism of AM inverse suspension polymerization was studied using conductivity, NMR, and electron microscopy.
In addition to the above methods, acrylamide and its derivatives can be modified by means of reactions, graft copolymerization, and composite actions. During the reaction, amine substances are introduced into organic chemical compound polyacrylamide, which is an important way to obtain cationic polyelectrolyte grafting. Common amines include dimethylamine, diethylamine, diethanolamine, etc. AM/AA is often used for graft copolymerization with starch to prepare high water-absorbing resin, or with other macromonomers to graft AM/AA on a certain type of film. High molecular weight cationic polyacrylamide is widely used in petroleum extraction, but HPAM has poor salt resistance. In order to improve the salt resistance of cationic polyacrylamide, Shang Zhenping and others synthesized terminal cationic polyacrylamide macromonomers, and initiated copolymerization of acrylamide, sodium acrylate, and polyacrylamide macromonomers using the iron (II) sulfate/isopropylbenzene peroxide oxidation-reduction system, resulting in the synthesis of (acrylamide-CO-sodium acrylate)-g-(β-amino propionic acid) graft copolymers.
Contact Us for More Information about Douwin Chemicals
Get in Touch
Email us with any questions or inquiries or use our contact data. We would be happy to answer your questions.