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N,N‐diallyl‐N,N‐dimethylammonium chloride (DADMAC) and vinyl ether of monoethanolamine (VEMEA) copolymer P(DADMAC‐VEMEA) were synthesized using radical polymerization in water media using ammonium persulfate as an initiator. The synthesis of this copolymer was investigated over a wide composition range at low conversion levels. The viscosity of the copolymers was measured in aqueous 1 M NaCl. Flocculating action and antimicrobial activities of the copolymers P(DADMAC‐VEMEA) against microbacteria and sulfate‐reducing bacteria (SRB) were studied. Synthesized copolymers had flocculating effects and can be used to purify wastewater from particles of bentonite clays. Also, the copolymer with a molar composition [DADMAC]: [VEMEA] = (80÷20):(20÷80) retarded the population of both bacteria, Gram‐positive (Staphylococcus aureus) and Gram‐negative (Escherichia coli) in the diffusion zone. Furthermore, the copolymer with a molar composition [DADMAC]:[VEMEA] = (90÷10):(20÷80) had bactericidal properties against SRB. Minimum inhibitory concentration (MIC) of the copolymer varied from 0.01% to 0.1% depending on the molar composition of the copolymer.

The kinetics of copolymerization is one of the key factors for optimization the process in large scale of production. Copolymerization of N, N‐dimethyl‐N,N‐diallyammonium chloride (DMDAAC) with N,N‐dimethyl acrylamide (DMAA) was studied by a dilatometer technique using ammonium persulfate ([NH4]2S2O8) as an initiator. The effect of the parameters (including molar ratio of DMDAAC to DMAA, concentrations of monomers [M] and initiator [I], and the temperature) on the polymerization rate was analyzed. From these analyses it was found that the polymerization rate (Rp) with the above variables can be represented as the following relationship: Rp∝ [M]2.63; Rp∝ [I]0.40 andRp∝[MDMDAAC:MDMAA]‐0,86.The negative order found in the relationship of the reaction rate and the monomer composition indicated that the DMDAAC concentration in the monomers composition conversely affected the polymerization rate. The overall activation energy for the polymerization rate was 39.56 kJ/mol in the temperature range between 40°C and 60°C. Based on the experimental results, the mechanism of polymerization is discussed in detail. Different thermal properties for DMDAAC and DMDAAC‐DMAA were observed by differential scanning calorimetry (DSC), and thermogravimetry (TG) analysis. Addition of DMAA to DMDAAC lowered the thermal stability relative to the home polymer of DMDAAC.