Synthesis, Characterization and Demulsification Performance of Polymethylamyldiallylammonium Chloride

Abstract

The lipophilic modification of dimethyldiallylammonium chloride monomer (DMDAAC) with resulting excellent lipophilic performance can provide an effective way to improve the application performance of the resulting monomers and copolymers. In this paper, polymethylamyldiallylammonium chloride (PMADAAC) homopolymer was prepared by using methylamyldiallylammonium chloride (MADAAC) as the monomeric unit, 2,2’-Azobis(2-methylpropionamide) dihydrochloride (V50) as the initiator and ethylenediaminetetraacetic acid tetrasodium (Na₄EDTA) as a metal ion complexing agent via an aqueous solution polymerization method. Using the intrinsic viscosity of the product as the inspection index, the polymerization reaction conditions were optimized by the response surface optimization method, and the optimum conditions obtained were: w(MADAAC)=70.2%, m(V50):m(MADAAC)=2.05%, m(Na₄EDTA):m(MADAAC) =0.0141%, T₁=55.0 °C, T₂=60.0 °C and T₃=80.1 °C, with the reaction lasting 9 h (see below). The average value of the intrinsic viscosity ([η]) of the obtained product was 0.84 dL/g, and the monomer conversion degree (Conv.) was 72.77%. The molecular weight characterizations of PMADAAC showed that the highest M_w of PMADAAC was 2.380 × 10⁵ and its polydispersity index d(M_w/M_n) was 1.952 for optimum properties. The results indicated that the introduction of the amyl group could increase the lipophilicity of the diallyl quaternary ammonium salts based on its good water solubility. For the demulsification performance of simulated crude oil O/W emulsions, the demulsification degrees were 88.9% for PMADAAC, 83.6% for polymethylpropyldiallylammonium chloride (PMPDAAC) and 45.5% for polydimethyldiallylammonium chloride (PDMDAAC), all at the same intrinsic viscosity.

Keywords:

• demulsification performance
• homopolymerization
• intrinsic viscosity
• methylamyldiallylammonium chloride
• response surface optimization

Acknowledgments

We are thankful for the financial support from the National Natural Science Foundation of China, grant # 51503100.

Data availability statement

The data that support the findings of this study are available on request from the corresponding author.

Conflicts of interest

The authors declare no conflicts of interest.