A block copolymer poly(ethylene glycol)-b-poly(vinylbenzyltrimethylammonium triflate), PEG-PVBTMA-OTf, and a homopolymer PVBTMA-OTf were synthesized through RAFT reactions. The polymers were studied in aqueous triflate solutions with varying temperatures, changing also the polymer and salt concentrations. The hydrophobic triflate anion turns polycations thermoresponsive, and they show an UCST. In the block copolymer, the interaction between the PEG and the cationic block makes the phase separation occur in distinct steps. Upon cooling, transparent solutions first turn turbid and then partially clear at T-cL. The T-cL is not observed in a mixed solution of PVBTMA-OTf and PEG macro-CTA. By considering the interplay between ionic, hydrogen bonding, and hydrophobic interactions, an overall picture of the complex phase separation processes is suggested.