氨基与硝基取代基对TYX系列耐热炸药热分解行为的影响:基于动力学模型的构效关系解析OA

To investigate the regulatory mechanism of amino and nitro substituents on the thermal stability of TYX series heat-resistant explosives,two novel heat-resistant explosives based on the bis(triazolo)tetrazine backbone-fully amino-substituted 2,7-diaminobis([1,2,4]triazolo)[1,5-b:1',5'-e][1,2,4,5]tetrazine-5,10-diium-3,8-diide(TYX-1)and mono-nitro mono-amino substituted 2-amino-7-nitrobis([1,2,4]triazolo)[1,5-b:1',5'-e][1,2,4,5]tetrazine-5,10-diium-3,8-diide(TYX-3)-were selected in this study.Their thermal decomposition behaviors were systematically compared using differen-tial scanning calorimetry(DSC)and thermal decomposition kinetic methods,while the decomposition processes were compre-hensively analyzed by thermogravimetry-infrared-mass spectrometry(TG-FTIR-MS).The results show that the difference in sub-stituents exerts a decisive influence on their thermal stability and decomposition pathways.TYX-1 exhibits a single high-temperature decomposition process with a peak temperature of 477.56℃(at a heating rate of 20℃·min-1),and its decom-position mechanism conforms to the random two-dimensional nucleation growth model(A2),consistent with the layered stack-ing structure promoted by amino groups and the resulting controlled two-dimensional energy release pathway.In contrast,TYX-3 shows a significantly lower decomposition temperature and multi-step decomposition characteristics:the initial stage follows a two-dimensional diffusion model(D2),followed by a multi-reaction competitive stage,and finally transitions to a skeletal frac-ture process dominated by the one-dimensional chemical reaction model(F1).Gas product analysis shows that the main decom-position products of TYX-1 are N2,CO2,N2O,and HCN,while additional products including NO,HCNO,NH2,and H2O are detected for TYX-3,confirming that the nitro group,as a strong oxidizing moiety,induces an unconventional decomposition pathway and promotes the oxidative cleavage of the parent ring skeleton.