Precisely Alternating Functionalized Polyampholytes Prepared in a Single Pot from Sustainable Thiolactone Building Blocks.

Polyampholytes with precisely alternating cationic and anionic functional groups were prepared using sustainable thiolactone building blocks in a simple one-pot procedure at room temperature and in water. Ring opening of the maleamic acid-functionalized homocysteine thiolactone monomer enabled the introduction of different functional groups into the polymer chain, which contributed to both ionic and hydrogen bonding interactions. The resulting polyampholytes exhibited various isoelectric points while maintaining high solubility in water under different pH and ionic strengths, which expands their potential applications. Finally, it is shown that the upper critical solution temperature (UCST) of these alternating polyampholytes in water/ethanol (30/70% vol) solutions can be tuned as a function of the content of ionic and hydroxyl groups.