Scope of sulfur dioxide incorporation into alkyldiallylamine-maleic acid-SO 2 tercyclopolymer.

Alternate copolymerization of diallylamine derivatives [(CH 2 CH[double bond, length as m-dash]CH 2 ) 2 NR; R = Me, (CH 2 ) 3 PO(OEt) 2 , and CH 2 PO(OEt) 2 ] (I)-maleic acid (MA) and (I·HCl)-SO 2 pairs have been carried out thermally using ammonium persulfate initiator as well as UV radiation at a λ of 365 nm. The reactivity ratios of ≈0 for the monomers in each pair I-MA and I·HCl-SO 2 ensured their alternation in each copolymer. However, numerous attempted terpolymerizations of I-MA-SO 2 failed to entice MA to participate to any meaningful extent. In contrast to reported literature, only 1-2 mol% of MA was incorporated into the polymer chain mainly consisting of poly(I- alt -SO 2 ). Quaternary diallyldialkylammonium chloride [(CH 2 [double bond, length as m-dash]CH-CH 2 ) 2 N + R 2 Cl - ; R = Me, Et] (II) also, did not participate in II-MA-SO 2 terpolymerizations. Poly((I, R = Me)- alt -SO 2 ) III is a stimuli-responsive polyampholyte; its transformation under pH-induced changes to cationic, polyampholyte-anionic, and dianionic polyelectrolytes has been examined by viscosity measurements. The p K a of two carboxylic acid groups and NH + in III has been determined to be 2.62, 5.59, and 10.1. PA III, evaluated as a potential antiscalant in reverse osmosis plants, at the concentrations of 5 and 20 ppm, imparted ≈100% efficiency for CaSO 4 scale inhibition from its supersaturated solution for over 50 and 500 min, respectively, at 40 °C. The synthesis of PA III in excellent yields from cheap starting materials and its very impressive performance may grant PA III a prestigious place as an environment-friendly phosphate-free antiscalant.