L-2100, a New Silicone Surfactant for Use in High Resilience Slabstock Foam

Abstract

A new high resilience (HR) slabstock foam stabilizer, Union Carbide Silicone Surfactant L-2100 (formerly Y-10704), has been discovered through the systematic study of surface tension and foam effects as the structure of this general class of siloxanes was varied. The investigations described in this paper show the influence of polarity of the pendant group grafted on the siloxane as a way to modify the properties of the silicone. The precise structure associated with L-2100 was defined through extensive evaluations in a variety of foam formulations including those containing SAN polymer polyols and melamine. The reduction of the surface tension of a complex polyurethane reaction mixture is a prerequisite to creating foam. Determining the proper siloxane structural parameters to satisfy these demanding requirements can be arrived at by carefully balancing the siloxane size with the character of the moiety attached to the silicon atom. The measurements of surface tension reduction in polyol solutions containing different foam stabilizer, coupled with thermodynamic calculations, have given us a better understanding of the role of high resilience foam. These fundamental findings led to the development of the Silicone Surfactant L-2100 already commercially available. The innovative molecular parameters designed into this novel, new HR surfactant provide for optimum surface activity to produce a stable, yet open foam, with outstanding processing characteristics. This new HR silicone surfactant has been successfully scaled-up, and its performance has exhaustively been evaluated in a variety of formulations on pilot scale equipment and in industrial foam facilities. Foams produced with L-2100 give excellent fingernailing and a regular nondeformed shape on the line. Additionally, increasing the concentration of L-2100 does not result in tighter foam. The performance and processing characteristics are a clear step forward in stabilizer technology and have been achieved through an alignment of the molecular parameters on the silicone backbone.