Polyurethane as Novel Catalyst for the Propoxylation of Fatty Amines

The propoxylation of fatty amines is a crucial reaction in the industrial production of surfactants. Catalyzing this reaction has so far proven unrewarding due to severe selectivity losses. In this study, rigid foam-structured polyurethane, i. e., an extremely inexpensive material which has not been used as a catalyst ever before, shows an unprecedented catalytic activity during the in-flow propoxylation of octylamine. The foam cells contain bound hydroxyl and amine groups that result in a bifunctional catalyst able to destabilize the ring structure of propylene oxide, and thus catalyze further propoxylation of fatty amines. An outstanding 10-fold reduction of the residence time without any loss of selectivity is achieved with respect to the un-catalyzed process. Furthermore, the polyurethane foam showed stable time-on-stream performance up to 10 bar and 110 °C.