In recent years there has been an increasing interest in water-soluble polymers containing propylene oxide moieties, especially copolymers between propylene oxide (PO) and ethylene oxide (EO) monomers. These may have either a block structure as the muchstudied (EO)x(PO)y(EO)x triblock copolymer [1-3], often referred to as Pluronic polymers, or a random distribution of PO and EO units, often referred to as Ucon polymers. A typical feature of polypropylene oxide (PPO) and polyethylene oxide (PEO) as well as copolymers of PO and EO is their reduced solubility in aqueous solution with increasing temperature. Much of the interest in these copolymers is rooted in the possibility that the solubility and other solution thermodynamic properties may be varied and optimised for various applications by appropriate choice of the relative proportions of PO and EO units in the chains.
