Synthesis of hydrophilic polyurethane particles in non-aqueous inverse miniemulsions

It is shown that it is possible to synthesize high molecular weight hydrophilic polyurethane particles by reacting either tolylene-2,4-diisocyanate or isophorone diisocyanate and oligoethylene glycol (M _n ∼200 g mol⁻¹) in non-aqueous inverse emulsions. This procedure offers the advantage that the formation of polyurea can be prevented in consequence of the absence of water in the emulsion. Apparent molecular weights of hydrophilic polyurethane as high as 19,000 g mol⁻¹ (M _n) were obtained.