Thixotropic polyurethane compositions as sealants for membrane separatory devices

摘要

Novel thixotropic polyurethane compositions particularly useful as sealants for the edges of folded membrane separatory devices are provided which comprise; (a) a prepolymer comprising the reaction product of a polyol having a hydroxyl functionality of at least 2 with one mole per hydroxy group of said polyol of an organic diisocyanate; and (b) a crosslinking agent comprising a polyether polyol having a hydroxyl functionality of at least 2 and a primary amine-terminated polyether having an amine functionality of at least 2. To accelerate curing of the composition, the crosslinking agent can be modified by employing primary hydroxyl-terminated polyethers and/or adding hydroxyl-containing tertiary amines.