黏结剂对喷雾干燥FOX⁃7基PBXs的性能影响

Effect of Binders on Properties of FOX⁃7 based PBXs by Spray Drying

为研究喷雾干燥制备高聚物粘结炸药(Polymer Bonded Explosives,PBXs)的包覆机理和黏结剂种类及含量对PBXs性能的影响,分别以聚酯型热塑性聚氨酯(Estane 5703)、氟树脂(F_(2314))、氟橡胶(F_(2602))和丙烯酸酯橡胶(ACM)为黏结剂,采用喷雾干燥技术制备细化FOX-7和含有不同黏结剂种类和含量的1,1-二氨基-2,2-二硝基乙烯(FOX-7)基PBXs。分别采用场发射扫描电子显微镜(FE-SEM)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)、撞击感度测试仪测试样品的表面形貌、晶型、热分解特性和撞击感度,研究黏结剂种类和含量对FOX-7基PBXs性能影响。结果表明,喷雾干燥包覆样品晶型均为α-FOX-7;Estane 5703包覆样品拥有最佳的球形度、表面光滑度和机械安全性,但表观活化能降低10.61%,F_(2602)包覆样品的热稳定性好,二者作为黏结剂均可有效降低FOX-7的撞击感度;黏结剂含量为3%~5%时,FOX-7基PBXs造型粉颗粒表面光滑,包覆黏结效果好;黏结剂含量为5%时,FOX-7基PBXs安全性能最佳。由FOX-7在熔融态下PBXs的微观形貌,分析喷雾干燥制备PBXs中黏结剂的包覆结构和降感机理,对比细化FOX-7和PBXs的撞击感度和表面元素原子比及化学态变化对其进行验证。

To figure out the coating mechanism of polymer bonded explosives(PBXs)prepared by spray drying and the effects of binders types and contents on the performance of PBXs,refined 1,1-diamino-2,2-dinitroethylene(FOX-7)and FOX-7 based PBXs with different binder types and contents were prepared by spray drying at the presence of poly ester urethane elastomer(Es-tane 5703),fluororesin(F_(2314)),fluorine rubber(F_(2602))and acrylic rubber(ACM)as binders,respectively.The surface morpholo-gy,crystalline states,thermal decomposition properties and impact sensitivity of the samples were characterized by field emis-sion scanning electron microscopy(FE-SEM),X-ray diffractometer(XRD),differential scanning calorimeter(DSC)and impact sensitivity instrument,respectively.The results indicated that the crystalline state of the resulting samples wasα-type.The FOX-7 based PBXs composited by Estane 5703 had the best sphericity,surface smoothness and mechanical safety,while the apparent activation energy decreased by 10.61%.The PBXs composited by F_(2602) exhibits satisfactory thermal stability.Both binders can ef-fectively reduce the impact sensitivity of FOX-7.When the compounded binders containing Estane 5703 and F_(2602) at the mass ra-tio of 4∶1 content was 3%-5%,the surface of FOX-7-based PBXs particles is smooth and the adhesive effect is attractive.When the compounded binder content was 5%,the resulting FOX-7-based PBXs possess excellent safety performance.The compositing structure and desensitization mechanism of binders in PBXs obtained by spray drying were analyzed from the microscopic mor-phology of FOX-7 in molten state.And the comparative analysis of impact sensitivity,atomic ratio of surface elements and chem-ical state changes between refined FOX-7 and resulting PBXs was carried out to verify them.