| 摘要 |
The invention disclosed relates to novel branched chain hydroxy-terminated aliphatic azido polymers and copolymers with variable molecular weight (MW) and a single step method for the preparation thereof which involves respectively reacting a high (MW) (0.5 - 5.0 x 106) solid rubbery polyepichlorohydrin (PECH) homopolymer and epichlorohydrin/alkylene oxide copolymer (PEEC), with an alkali metal azide in a suitable organic solvent, in the presence of an initiator at elevated temperature. The MW of the azido product may be controlled by including in the reaction mixture a basic degradation catalyst (such as LiOCH3 or NaOH) and varying the amount of catalyst. When the reaction is catalyzed, the MW of the proudct varies within the range 1,000-40,000 and the hydroxyl functionality is 2-10. Uncatalyzed reactions yield products with MW between 40,000 and 200,000 and a functionality of about 10. The branched azido polymers and copolymers yield energetic binders with improved mechanical properties and thermal stability which are useful in rocket propellants and composite explosives formulations.
|
