| 摘要 |
<p>Salicylate ester-blocked polyisocyanates are of formula (Ie (where X is an organic gp. of valency n+m; R is H or 1-10C alkyl; R1 is 1-10C alkyl or 6-10C aryl; n is >=1; m is 0 or 1; m+n is >=2). Used for reaction with polybutadiene with end OH gps. to form polyurethane prepolymers suitable as binders for rocket propellants. Pot life of the mixt. of binder and rocket fuel granules during casting at 28 degrees C is extended, which dissociation occurs at hardening temp., e.g. 63 degrees C, so that hardening time is not extended.</p> |
