A novel ternary copolymerized polyzwitterionic of poly (AM/DMAM/MAEDAPS): synthesis and solution properties

3-[2-(N-methylacrylamido)-ethyldimethylammonio] propanesulfonate (MAEDAPS), a novel zwitterionic monomer, was designed and synthesized in this study. Then it reacted with acrylamide and N, N-dimethyl acrylamide by free radical polymerization in aqueous solution with ammonium persulfate ((NH4) 2S2O8) and sodium sulfite (NaHSO3) as initiator. The structure of MAEDAPS was characterized by H-1 NMR and IR. Thermal stability of the obtained copolymer was tested by DSC, TGA and TG-IR analysis. Glass transition temperature (Tg) and melt temperature (Tm) was observed by DSC, meanwhile, the thermal degradation process was studied via TGA and TG-IR. It turned out that the thermal degradation process can be divided into three stages including removal of physically absorbed water, decomposition of side groups and degradation of polymer main chain. Anti-polyelectrolyte behavior was observed based on the intrinsic viscosity. Solution properties of ternary copolymer were exhibited by reduced viscosity. The result showed that the addition of small molecular electrolytes weakened the coulomp attraction between sulfonic acid group and quaternary ammonium group, and the conformation became extend, which led to the increase of hydrodynamic volume and reduced viscosity. The ability of monovalent and divalent cationic charges influencing the viscosity of zwitterionic copolymer obeyed the following sequence: K+ < Li+ < Na+, Cu2+ < Ca2+ < Mg2+, and anions was in the order: Cl- < I- < Br-.