Effect Of Substituents On The Monomer Reactivity Of Substituted Diallylmethyl Ammonium

In this paper, the influence of substituents of substitued diallylmethylammonium chloride on the monomer reactivity was studied.On the basis of reported methods and previous work in our group, several substitued diallylmethylammonium chloride were selected and synthesized. The substituents were propyl, pentyl, benzyl, p-methyl benzyl and p-nitro benzyl group. All the monomers were characterized by FTIR and1HNMR. The kinetics of the substituted diallylmethylammonium in aqueous solution was studied by using dilatometer method, and the apparent activation energy for each monomer homopolymerizaiton via APS initiation system was mearured. The influences of polarity and space effect on the monomer reactivity were obtained by comparing the value of kinetic parameters of homopolymerization.The results showed that when the substituents were propyl, pentyl, benzyl, p-methyl benzyl and p-nitro benzyl group, the apparent activation energies were Ea1=96.70kJ/mol, Ea2=91.25kJ/mol,Ea3=96.70kJ/mol,Ea4=68.10kJ/mol, Ea5=61.64kJ/mol,Ea6=77.25kJ/mol, respectively. The polymerization rate equations were Rp1=k1[I]0.72[M]1.92,Rp2=k2[I]0.74[M]1.93,Rp3=k3[I]0.75[M]1.93,Rp4=k4[I]0.71[M]1.23, Rp5=k5[I]0.67[M]1.34,Rp6=k6[I]0.57[M]1.07,respectively, when the polymerization temperature was50℃. While the polymerization rates decreased with the order that Rp1>Rp2>RP3>Rp5>Rp4>Rp6under the same polymerization conditions.It can be proved that, the polymerization rates decreased and the apparent activation energies increased with the lengths of the side-chain, which meant of the decreased monomer polymerization activity as a result of increased space effect of the side-chain, under the same homopolymerization conditions. When the electron-withdrawing ability of the substituents. increased, the polymerization rates decreased and the apparent activation energies increased, which meant of the deceased monomer polymerization possibly as a result of polarity effect of the substituents.The research results mentioned above could offer guidance for the designing and synthesizing of polymers of substituted diallylammonium with different hydrophilic-hydrophobic groups, and also be the research foundation of the polymerization conditions of the these polymers.