Polyurethane as Novel Catalyst for the Propoxylation of Fatty Amines

Abstract

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.