Abstract
Diallylbis[(3-ethoxycarbonylpropyl)ammonium chloride] (CH2=CHCH2)(2)N+[(CH2)(3)CO2Et](2), a new symmetrical diallyl quaternary ammonium salt, has been cyclopolymerized to its cationic polyelectrolyte (CPE) (+) I having pyrrolidine rings embedded in the polymer backbone. Polymer I would exemplify for the first time a cyclopolymer with each repeating unit bearing two identical 3-carboxypropyl pendants. (CPE) (+) I upon hydrolysis afforded pH-responsive polycationic acid (+) II, which upon successive deprotonation was transformed into a polyzwitterion acid (+/-) III and polyzwitterion-anion (+/- -) IV. Because of similar degrees of polymerization for I-IV, a meaningful comparison of their solution properties was possible. While I, II, and IV demonstrated polyelectrolyte like viscosity behavior, (+/-) III showed anti-polyelectrolyte properties. The anionic portion in (+/- -) IV controlled its solution properties. Polymer (+/- -) IV demonstrated remarkable antiscalant behavior; at a concentration of 15 ppm, it inhibited the precipitation of CaSO4 from its supersaturated solution with a scale inhibition efficiency of a parts per thousand 100% even after 300 min. This study opens up the possibility of using the current polymer as an antiscalant in reverse osmosis plants.