Polyaddition (2): Polyurethane formation

Principle
(Poly)hydroxy compounds react with (poly)isocyanates by forming a polymer. Since this reaction is highly exothermic, the resulting plastic is formed by evaporating propellant. Foams can be also formed by gases originating during this reaction. Polyurethane foam is produced in this experiment.The reaction process is relatively complex, however, can be depicted simplistically in the form given here. As propellant works only partly evaporating water, the essential component is carbon dioxide, which is formed during the reaction of the water with isocyanate groups.

Learning objectives

•  Principle scheme of an polyaddition reaction

Benefits

• Easy teaching and efficient learning by using interactive experimentation PHYWE-Software
• Experiment is part of a complete solution set with experiments for the topic Chemistry of Polymers matched with international curriculum: all topics are covered