Catalyst Cell opening blowing

XF-N1085 Newly developed non-fugitive cell opening blowing catalyst. APCI... 

Materials. The flexible polyurethane (polyether) foam, formulated from a polyol, tolylene diisocyanate, emulsifier, catalyst, and blowing agent, was obtained from the Nopco Chemical Co. It had a density of about 1.5 pounds per cubic foot (0.02 gram per cc.) and contained approximately 40 open cells per linear inch. The foam samples were washed in detergent, dried, and weighed before being irradiated. 

A typical phenolic foam system consists of liquid phenolic resin, blowing agent, catalyst, surface-active agent, and modifiers. Various formulations and composite systems (60-62) can be used to improve one or more properties of the foam in specific applications, such as insulation properties (58,63-66), flammability (67-69), and open cell (70-73) quality. 

The foam is prepared by adjusting the water content of the resin and adding a surfactant (eg, an ethoxylated nonionic), a blowing agent (eg, pentane, methylene chloride, or chlorofluorocarbon), and a catalyst (eg, toluenesulfonic acid or phenolsulfonic acid). The sulfonic acid catalyzes the reaction, while the exotherm causes the blowing agent, emulsified in the resin, to evaporate and expand the foam (121). The surfactant controls the cell size as well as the ratio of open-to-closed cell units. Both batch and continuous processes are employed. In the continuous process, the machinery is similar to that used for continuous polyurethane foam. 

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