Polymethylene polyphenylamine modified diamine chain extenders and polyurea elastomers therefrom

摘要

Reaction injection molded polyurea elastomers are disclosed that are derived from the reaction of (1) an aromatic polyisocyanate; (2) primary or secondary amine terminated polyethers; and (3) an aromatic amine extender combination comprising (a) an aromatic diamine having at least one of the positions ortho to each amine group substituted by a lower alkyl group and (b) a polymethylene polyphenylamine. The use of the polymethylene polyphenylamine component allows for the retention of the good physical properties of the prior art polyureas while at the same time effecting a cost reduction in the preparation of this useful class of polymers.