| 摘要 |
Polyurethanes may be conveniently made by curing isocyanate-terminated urethane prepolymers with a N,N'-dialkylmethylenedianiline. The diamine N,N'-di(2-butyl)-4,4'-methylenedianiline is a particularly useful diamine. The resulting polyurethanes often are thermoplastic rather than thermosetting, making them especially useful as coatings, adhesives, and sealants. Such secondary aromatic diamines have acceptable pot lives and afford products with a variety of properties. |
