摘要:
3 ,6-Dihydrazine-1 ,2 ,4 ,5-tetrazine- 3 ,5-dinitrosalicylic acid salt dihydrate (DHT · 2DNS · 2H2O ) was synthesized using 3 ,6-dihydrazine-1 ,2 ,4 ,5-tetrazine (DHT ) and 3 ,5-dinitrosalicylic acid (DNS ) as raw materials and its structure was characterized by nuclear magnetic resonance spectroscopy ,infrared spectroscopy ,element a-nalysis and thermogravimetry . The thermal behavior and thermal decomposition products of anhydrous DHT · 2DNS were studied by differential scanning calorimetry (DSC) and thermogravimetry combined with Fourier trans-form infrared analysis (TG-FTIR) . The constant-volume combustion heat (Δc U ) was determined by an oxygen bomb calorimeter and the standard molar enthalpy of combustion (Δc H ㈠m ) and the standard molar enthalpy of forma-tion (Δf H ㈠m ) were estimated via the Δc U .The results show that the thermal stability of DHT · 2DNS is higher than DHT and its thermal decomposition process can be divided into four stages .Firstly ,part of hydroxyl ,nitro and car-boxyl in DNS ion of DHT · 2DNS were removed and hydrazine was decomposed ;then ,the tetrazine ring and groups on the benzene ring was dissociated ,thirdly ,benzene ring was broken ;finally ,the benzene residues kept decompo-sing .The values of Δc U ,Δc H ㈠m and Δf H ㈠m of DHT · 2DNS are ( - 11938 .17 ± 25 .33)J/g ,( - 7119 .77 ± 15 .16)kJ/mol and ( - 1177 .2 ± 11 .14)kJ/mol ,respectively .%以3,6-二肼基四嗪(DHT)和3,5-二硝基水杨酸(DNS)为原料,合成了3,6-二肼基-1,2,4,5-四嗪二硝基水杨酸盐二水合物(DHT·2DNS·2H2 O),采用核磁共振波谱 、红外光谱 、元素分析及热重法对其结构进行了表征.采用差示扫描量热法(DSC)并结合热重-红外联用(TG-FTIR)对无水DHT·2DNS的热行为及热分解产物进行了研究.利用氧弹量热仪测定了DHT·2DNS的恒容燃烧热(Δc U),并通过 Δc U估算了标准摩尔燃烧焓(Δc H㈠m)和标准摩尔生成焓(Δf H㈠m).结果表明,DHT·2DNS的热稳定性要高于DHT,其受热分解可分为4个阶段:首先DHT·2DNS的二硝基水杨酸离子脱去羟基和部分硝基 、羧基,同时肼基发生分解;然后苯环上的基团与四嗪环发生解离;随后苯环发生裂解;最后苯环残余物继续发生分解.DHT·2DNS的 Δc U值 、Δc H㈠m值和 Δf H㈠m值分别为(-11938.17±25.33)J/g、(-7119.77±15.16)kJ/mol和(-1177.2±11.14)kJ/mol.