Synthesis and solution properties of a quaternary ammonium polyelectrolyte and its corresponding polyampholyte

The quaternary ammonium salt, N,N-diallyl-N-5-carbomethoxypentyl-N-methylammonium chloride (DACPMAC), on cyclopolymerization in aqueous solution using tert-butylhydroperoxide, afforded the polyelectrolyte poly(DACPMAC), having five-membered cyclic structure on the polymeric backbone, in excellent yield. The polyelectrolyte on acidic hydrolysis of the pendent ester groups gave the corresponding polyampholyte poly(DAMAH) having the equivalent of 6-(N,N-diallyl-N-methyl ammonio) hexanoate (DAMAH) as monomeric unit. The solution properties of these polymers as well as the polyelectrolyte, poly(DACMMAC), and its corresponding polyampholyte, poly(DAMAE), [having the monomeric unit equivalent of N,N-diallyl-N-carboethoxymethyl-N-methylammonium chloride (DACMMAC) and N,N-diallyl-N-methyl ammonio ethanoate (DAMAE)] are investigated by potentiometric and viscometric techniques. Basicity constants of the polyampholytes are found to be ‘apparent’ and as such follow the modified Henderson–Hasselbalch equation. While the protonation of the polyampholyte poly(DAMAH) becomes more and more difficult as the degree of protonation (α) of the whole macromolecule increases, the polyampholyte poly(DAMAE), exhibits the reverse trend i.e. the protonation process becomes easier and easier with increasing α.