Hydrotropes exhibit pronounced effects on the solubility of
amphiphilic block copolymers in water. Effects on the CP and
CMC for many nonionic polymers have recently been reported
[23,39–41]. A study by Mansur et al. [42•] examined the effects
of the hydrotropes sodium p-toluene sulfonate (NaPTS) and
butyl monoglycol sodium sulfonate (NaBMGS) on poly
(ethylene oxide–propylene oxide) (PEO-PPO) block copolymers
in water. The CMC and CP of PEO-PPO were shown to
increase and the surface tension decrease with the addition of
either hydrotrope. The effect, however, was more pronounced
for NaBMGS.NMRstudies revealed that NaPTS interacted with
the hydrophilic portion of the polymer while NaBMGS helped
solubilize the hydrophobic portion. This suggests that hydrotropes that interact favorably with the hydrophobic portion
of the polymer have a more pronounced effect on solubility.