Cyclopolymerization protocol for the synthesis of a poly(zwitterion‐alt‐sulfur dioxide) to investigate the polyzwitterion‐to‐poly(anion‐zwitterion) transition

Abstract

The zwitterionic monomer, 3‐(N,N‐diallyl,N‐carboethoxymethylammonio)propanesulfonate, on cocyclopolymerization with sulfur dioxide in DMSO using azoisobutyronitrile as the initiator afforded the polyzwitterion (PZ) copolymer in excellent yields. The PZ on acidic hydrolysis of the ester groups led to the corresponding polyzwitterionic acid (PZA). The pH‐responsive PZA on treatment with sodium hydroxide gave the new poly(eletrolyte‐zwitterion) (PEZ). The solubility, viscosity behaviors, and solution properties of the salt‐tolerant PZ, PZA, and PEZ were studied in detail. Like common PZs, PZ was found to be insoluble in salt‐free but soluble in salt‐added water. The apparent basicity constants of the carboxyl group in PEZ have been determined. As the name implies, the PEZ possesses dual type of structural feature common to both conventional anionic polyelectrolytes and PZs, and its aqueous solution behavior is found to be similar to that observed for a typical alternating anionic‐zwitterionic copolymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Structures and Synthesis of Zwitterionic Polymers

“…In fact, it seems that nearly the full spectrum of polymerizable groups suited for radical polymerization has been used to make polyzwitterions in the past, including not only styrenes, vinylpyridines, vinylimidazoles or vinylesters [124], but also rather uncommon polymerizable groups such as dienoic acids [123,124,[131][132][133][134][135][136][137][138][139], vinylcyclopropanes [124,134] or isocyanides [69], and cyclopolymerizing species such as diallylammonium [64,87,88,124,134,[140][141][142][143][144][145][146][147][148][149][150][151][152][153] and closely related divinyl monomers [93,94]. Moreover, a number of monomers confined exclusively to (often alternating) radical copolymerization, such as vinylethers [124,134], fumarates and maleates [124,134,[154][155][156], isobutylenes [157] and ...…”

“…This has resulted in a continuous interest in zwitterionic diallylammonium carboxy-, phosphono-and sulfobetaines (cf. Figure 16, P-68 and P-69) [64,87,88,124,134,[140][141][142][143][144][145][146][147][148][149][150][151][152][153]431,433].…”

“…As the polymerizability of allyl monomers is often low, it has been often improved by alternating copolymerization with sulfur dioxide, SO 2 [134,141,[144][145][146][147]150,153,174,[434][435][436]. Though this approach provides a non-hydrolyzable all-carbon linker between the zwitterionic site and the polymer chain, it is somewhat ambiguous, as the aliphatic polysulfone backbone produced is sensitive to thermal stress and strongly basic conditions by itself.…”

Switchable Materials Containing Polyzwitterion Moieties

“…Polysulfobetaines poly (30), poly(32), poly (34) and poly (36) were transformed via hydrolysis to polymers also bearing secondary negatively charged functionalities. In the case of poly (30) and poly (32), acidic hydrolyses of the carboxybetaine ester with 6 M HCl were performed at 53˝C for 48 h and neutralization with two equivalents of NaOH resulted in the formation of polymers poly(31) and poly (33) [67,68]. Similarly, the acidic hydrolysis of phosphate diester in poly (34) and poly (36) was performed at 95˝C in 24 h [69,70].…”

“…Polymers 2015, 7, page-page carboxybetaine ester with 6 M HCl were performed at 53 °C for 48 h and neutralization with two equivalents of NaOH resulted in the formation of polymers poly(31) and poly (33) [67,68]. Similarly, the acidic hydrolysis of phosphate diester in poly(34) and poly (36) was performed at 95 °C in 24 h [69,70].…”