液态氟橡胶改性端羟基嵌段共聚醚粘合剂及其对铝粉热氧化行为的影响

The combustion of aluminum powder promoted by fluoride is a hot spot in the field of energetic materials in recent years. Hydroxyl terminated liquid fluororubber with high fluorine content is selected as fluorine source, which is introduced into hydroxyl-terminated polyether (HTPE) adhesive system to prepare modified HTPE films with different fluorine rubber contents.The morphology, mechanical properties, thermal stability and oxidizability of the modified HTPE films were tested and analyzed. The results show that the mechanical properties of the film decrease first and then increase with the increase in fluororubber content. The tensile strength and elongation at break of the film with fluororubber content of 50 wt% are 2.51 MPa and 217%, respectively. Compared with the unmodified HTPE film, its tensile strength is increased by 83%, and its elongation at break is decreased by 17%. Liquid fluororubber promotes the decomposition of HTPE polyurethane adhesive, and the initial decomposition temperature shifts from 263 ℃ to 209 ℃. The fluorine-containing oxidizing gas decomposed by the modified adhesive reacts with the alumina shell of aluminum powder to form AlF₃, which promotes the release of internal active aluminum core.