Significantly Reduced Catalyst Consumption in Rigid Foams

Abstract

The use of Mannich base initiated polyether polyols for the production of rigid polyurethane foams has been employed for many years. The use of this class of polyols has primarily been directed toward sprayed polyurethane foam applications. The inherent properties of these polyols include aromatic character, increased compatibility and inherent catalytic capabilities. The use of this family of polyols has not widely spread to other rigid foam applications. During the transition to HCFC-141b as the primary blowing agent for rigid polyurethane foams, increased catalyst levels were required. This introduced additional cost and handling concerns. This paper presents 20 rigid foam formulations which show how the use of a variety of Mannich polyols can reduce catalyst consumption by more than 40% while maintaining compressive strength, flowability and maintaining or improving the insulation properties of the foam (K-factor) and dimensional stability.

Commercial Flame Retardancy of Polyurethanes

“…Polyols containing aromatic rings, such as the ''Mannich polyols'' made from diethanolamine, formaldehyde, and phenols, are favorable to flame retardancy not only because of the nitrogen content, which also provides some foaming catalysis, but because the phenolic rings enhance char formation during burning [29]. Rigid water-blown foams with much-improved flame retardancy can be made using combinations of an ultra-low viscosity Mannich polyol with another polyol, according to Dow [30].…”