摘要 |
<p>Polyurethane elastomeric foam by foaming a prepolymer or polyisocyanates and compounds having at least two hydrogen atoms reactive to isocyanates, and a chain-lengthening polyamine agent, in the presence of an expanding agent containing a component reactive with the polyamine chain-lengthening agent or with the products of reaction thereof with polyisocyanates, and split-off gas.</p> |