摘要
为分析浇注PBX炸药交联密度与力学性能的关系,在70℃时对浇注PBX炸药样品进行高温加速老化试验,对比分析了平衡溶胀法和核磁共振(NMR)法测定交联密度的差异,研究了其在常温时的抗拉强度(σm)、抗压强度(σb)、压缩率(εb)、抗剪强度(τ)、硬度(SH)与黏结剂母体凝胶分数(G)、交联密度(ve)之间的关系。用动态热机械分析仪(DMA)分析了不同老化时间下样品损耗因子tanδ和黏弹系数的变化规律。结果表明,PBX炸药样品的交联密度在老化初期增加,老化中期略有降低,老化后期又增加;NMR法因其测试简单、快捷,精确度高、试样非破坏性等优点,可以作为今后浇注PBX炸药交联密度表征方法的一个重要发展方向;样品老化过程中,浇注PBX炸药样品的交联密度与各力学性能的变化呈线性相关,其力学损耗降低的原因是黏结剂母体的G和v_e增加,浇注PBX炸药的降解和交联是由黏结剂母体结构变化引起。
In order to disclose the relationship between the crosslink density and the mechanical properties,casting polymer bonded explosive （PBX） samples were aged at 70℃.The characterization methods of crosslink density by equilibrium swelling and nuclear magnetic resonance （NMR） were compared and analyzed.The relationship between different mechanical properties at room temperature,including maximum tensile strength （σm）,compressive strength （σb）,compression ratio （εb）,shear strength （τ） and hardness（SH）,and the binder matrix structural crosslinking parameters,including gel fraction （G）and crosslink density （ve） were studied.The variation trend of loss factor and viscoelastic modulus at various aging time were analyzed by dynamic thermomechanical analysis （DMA）.The results show that crosslink density increases at the beginning of aging,decreases in the middle of aging and then increases at the last stage of aging again.NMR is regarded as a promising characterization method of the crosslink density for casting PBX due to its simple,fast,high-precision and nondestructive nature.During the aging process,linear relationship between different mechanical properties and crosslink density is evaluated for casting PBX,and the decreasing of mechanical loss is caused by increasing of binder matrix G and ve.Moreover,the degradations and crosslinking are caused by changing of the structures of binder matrix.
作者
王芳芳
常海
张林军
王琼
WANG Fang-fang CHANG Hai ZHANG Lin-jun WANG Qiong(Xi＇an Modern Chemistry Research Institute, Xi＇an 710065, China)
出处
《火炸药学报》
EI
CAS
CSCD
北大核心
2017年第2期69-74,共6页
Chinese Journal of Explosives & Propellants
基金
国防重大基础科研项目(No.004040204)
