GAP黏合剂基体与ε-CL-20界面作用

Surface Interaction between GAP Binder Matrix andε-CL-20

采用原位拉伸扫描电镜观察了硝酸酯增塑聚醚(NEPE)推进剂(叠氮缩水甘油醚(GAP)/六硝基六氮杂异伍兹烷(ε-CL-20)推进剂、聚乙二醇(PEG)/奥克托今(β-HMX)推进剂)的拉伸断裂过程,利用反相气相色谱法(IGC)和接触角法研究了推进剂组分间粘附功,并通过分子动力学(MD)模拟计算了粘结剂/炸药复合体系的结合能,表征了黏合剂体系与炸药之间的相互作用强度。结果表明,相同拉伸作用下,GAP/ε-CL-20推进剂首先在大颗粒附近发生“脱湿”,裂缝扩展速度较快,形成裂纹带,伴随黏合剂基体断裂,形成宏观裂纹,应变大于60%后,推进剂发生整体断裂;而PEG/β-HMX推进剂中发生“脱湿”的颗粒附近有黏合剂基体变形形成的胶丝连接,裂缝扩展速度较慢,直至应变大于80%后推进剂发生断裂;GAP基体与ε-CL-20之间的粘附功70.69 mJ·m^(-2)和结合能259.90 kJ·mol^(-1),均低于PEG基体与β-HMX之间的粘附功98.61 mJ·m^(-2)和结合能335.65 kJ·mol^(-1),即GAP基体与ε-CL-20的界面粘结情况较弱,显著影响了GAP/ε-CL-20推进剂的力学性能。

It is reported herein that the interfacial adhesion between binder and filler has distinct effect on mechanical properties of propellant.The tensile fracture progress of propellant(nitrate ester plasticized glycidyl azide polymer(GAP)/hexanitrohexaazaisowurtzitane(ε-CL-20)polyether propellant and polyethylene glycol(PEG)/octogen(β-HMX)polyether propellant)was monitored by in-situ tensile scanning electron microscope.In addition,the interaction strength between binder matrices and solid fillers was characterized by adhesion work and binding energy.The adhesion work was studied by inverse gas chromatography(IGC)and contact angle method,and the binding energy was calculated via molecular dynamics(MD).Results shows that the dehumidification and fracture expanding progress of GAP/ε-CL-20 propellant are more serious than these of PEG/β-HMX propellant during stretching progress.GAP/ε-CL-20 propellant breaks when the elongation is more than 60% while PEG/β-HMX propellant breaks when the elongation is more than 80%.Besides,the adhesion work 70.69 mJ·m^(-2) and binding energy 259.90 kJ·mol^(-1) between GAP matrix and ε-CL-20 are both lower than the adhesion work 98.61 mJ·m^(-2) and binding energy 335.65 kJ·mol^(-1) for PEG/β-HMX system,suggesting that the poor interfacial adhesion between GAP binder matrix and ε-CL-20 is one of main reasons for inferior mechanical properties of GAP/ε-CL-20 propellant.