Preparation of DMDAAC/AM Copolymer by Aqueous Dispersion Polymerization

With dimethyldiallyamine chloride (DMDAAC) and acrylamide (AM) as the source monomers, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as dispersant and [2-(2-imidazoline-2-yl)propane] dihydrochloride (VA-044) as initiator, the aqueous dispersion copolymer of P (DMDAAC-AM) was synthesized in the solution of ammonium sulfate. The effects of the main reaction parameters, such as the concentrations of PDMC, ammonium sulfate and VA-044, the reaction time and temperature, on the molecular weight and the particle size of the polymer, the amount of residual monomers and the stability of the dispersion were investigated. The results indicate that the suitable reaction conditions for obtaining stable cationic polyacrylamide dispersion are as following: concentrations of 1.0%~3.5% for PDMC, 22%~30% for ammonium sulfate and 1.6×10–4~4.2×10–4 g·(g monomer)–1 for VA-044, the reaction time in the range of 5~7 h and the temperature range of 50~60℃.