Effect of substitution groups on the homopolymerization activity of methyl aryl diallyl ammonium chloride

Abstract

Dimethyl diallyl ammonium chloride (DMDAAC), recognized for its high positive charge density among the several diallyl quaternary ammonium cationic monomers, has been constrained in lipophilic applications by its structure. In this article, benzyl, p-methylbenzyl, and p-nitrobenzyl were introduced as structural modifications of DMDAAC to compensate for this. The effects of the introduced aryl structures on the molecular structure of the modified diallyl methyl aryl ammonium chloride and the polymerization activity of the monomers were explored by quantum chemical calculations and homopolymerization kinetic studies with ammonium persulfate (APS) as initiator. The results intuitively revealed the negative effect posed by the electronabsorbing effect of the substituents on the polymerization activity of the monomers, and also highlighted the important role of the steric effect. The above work has provided a good theoretical foundation and experimental reserve for further research on the preparation and application of methyl aryl diallyl ammonium chloride.

The comparison of polymerization activity of typical cationic quaternary ammonium salt monomers

“…Therefore, when the monomer molecules approach the active center in the reaction, they will encounter high hindrance potential barriers that prevent polymerization 29 . Xu's research indicated that the electron‐donating ability of the methyl group was inadequate to offset the negative effects of the steric hindrance 13 . Therefore, the polymerization activity of DMC was lower than that of DAC.…”

“…29 Xu's research indicated that the electron-donating ability of the methyl group was inadequate to offset the negative effects of the steric hindrance. 13 Therefore, the polymerization activity of DMC was lower than that of DAC.…”

“…12 It is usually believed that the polymerization activity of DMDAAC is low due to 2 reasons: firstly, the strongly electron-withdrawing effect of quaternary ammonium salt on the electronic cloud in double bonds with a short distance to the salt and secondly, the steric hindrance needed to be overcome in the ring closure process. 13 Relatively, the positive charge center in the structure of acryloyl oxygen alkyl quaternary ammonium salt monomer and acrylamide alkyl quaternary ammonium salt monomer is far away from the double bond, which makes it easy to polymerize. So, there are so many researches focused on the polymerization process and kinetics of these monomers.…”