Preparation of a Flexible Polyurethane Foam

Safety precautions Before this experiment is carried out. Sect. 2.2.5 must be read as well as the material safety data sheets (MSDS) for all chemicals and products used. 

10 g of a polyester with an OH number of 60 (see Example 4.1a) and 3.5 g of toluene diisocyanate are well mixed in a 250 ml plastic beaker for 1 min using a wooden stick. A mixture of 0.1 g of AAi-dimethylbenzylamine, 0.2 g of 50% aqueous solution of a non-ionic emulsifier, 0.1 g of an aqueous solution of sodium dodecyl sulfate, 0.025 g of a poly(dimethylsiloxane), and 1 g of water are then added with intensive stirring. After 1 min the expansion of the foam is practically finished 20-30 min later (depending on the prevailing atmospheric conditions) the surface of the polyurethane foam is no longer tacky. The flexible foam (total volume about 150 cm ) can now be removed from the beaker and mechanically stressed after a day. 

Main applications of flexible polyurethane foams are in mattresses, upholstery, and packaging. 

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