A facile synthesis of hydrophobically end-capped poly(oxymethylene-co-polyethylene oxide) by controlled step condensation

A very easy one-step and ambient temperature method for the direct synthesi s of water-soluble associative triblock poly(ethylene oxide) (PEO) polymers is described. It involves the step polymerization of PEO chains with activ ated dihalides such as dichloromethane in the presence of potassium hydroxi de powder. The addition of selected amounts of poly(ethylene oxide)stearyl ether allows the degree of polymerization to be controlled and hydrophobica lly end-capped poly(oxymethylene-co-polyethylene oxide) structures to be ob tained in a large range of molecular weights. These triblock structures are comparable to the well-known hydrophobically end-capped urethane polymers (HEUR) demonstrating interesting associative properties in water.