Process for preparing polycarbonates

Polycarbonate type nonionic surfactant compositions comprising monohydroxy alcohols capped with polycarbonate groups. More specifically, the surfactant compositions comprise aliphatic, nonaromatic cycloaliphatic or aromatic alcohols which have been capped with block polycarbonate groups formed by the reaction of the alcohols with ethylene carbonate in the presence of an alkali metal salt catalyst. The surfactant properties of the compositions may be varied by first reacting the alcohols with ethylene oxide to form a block polyether group cap on the alcohols before the reaction with ethylene carbonate or by further reacting the polycarbonate capped alcohols with ethylene oxide to form a terminal polyether block group. The surfactants formed are a random distribution mixture of compositions wherein 2 to 20 moles of ethylene carbonate and 3 to 50 moles of ethylene oxide per mole of the alcohols are reacted together.