高氯酸羟胺热分解动力学

第51卷第1期化工报Vol. 51 No l2000年2月Journal of Chemical Industry and Engineering( ChinaFebruary 2000研究简报A高氯酸羟胺热分解动力学米镇涛常志华张香文邱立勤王亚权天津大学化工学院,天津300072)关键词高氯酸羟胺分解动力学热分析图分类号O643.122实验结果高氯酸羟胺(HAP)是一种用于推进技术领21热失重分析域的新型高能氧化剂,在高性能推进系统中具有极4个体系的热重曲线如图1所示.由于HAP为重要的价值1-31吸湿,其热重曲线在100℃以下部分主要与其脱水用热分析技术研究含能物质的热分解,已有大有关,图2为纯HAP热分解的TG-DIG曲线图量报道45.而对于HAP的热分解的报道较少6-81,采用热分析技术研究HAP的分解动力学目前还没有文献报道.本文用热解重量分析法(TG)和差示热分析(DTA)对HAP的热分解进了研究.根据HAP合成及贮运中可能引入的杂EE质,研究了NH4+、H、Fe3+对HAP热分解行为的影响1实验部分3003504004505005506001.1高氯酸羟胺固体样品的制备Fig 1 TG curves of HAP samples将HAP水溶液及含有添加物的HAP水溶液减1-HAP+Fe+; 2-HAP: 3-HAP+ NHA;4-HAP+H压下蒸发(<80℃),浓缩后结晶,制得如下HAP固体样品:纯HAP固体结晶;含高氯酸铵α4.0%的HAP固体;含高氯酸α=3.0%的HAP固体;含三氯化铁(Clˉ对HAP热安定性无影响j1ae=0.29%的HAP固体1.2热分析实验IG和DTA分别在日本岛津公司制造的TGA50型热重分析仪和DTA-50型差热分析仪上进行由于HAP吸湿,通过试验确定在100℃停留30300350400450500550600min作为脱水条件,在此条件下HAP不发生分解TG实验是在20 mt min的氮氛下以10℃.min1中国煤化工升温至100℃,停留30min,再以8℃min1升温of neat hapCNMHG至300℃结束.DTA实验的氮气流速为50m其他条件同热重分析从图1可以看出,与纯HAP的分解相比,含高氯酸铵的HAP以及含高氯酸的HAP的分解被延迟,而含氯化铁的HAP的分解则提前了.表1给134化工报2000年2月出了4种样品的分解温度,从表中数据可以看到,使得总放热量降低较多.含铵HAP和含酸HAP由氯化铁对HAP分解的促进作用很明显,它使HAP于含有杂质,因此它们的焓差绝对值要低于纯的分解峰温提前了大约65K,分解温度区间ΔTHAP的焓差绝对值.由于在该条件下高氯酸铵还也比其余样品小10K左右,而且其失重曲线很陡,没有发生分解,故含铵HAP的焓差绝对值比含酸说明分解速度非常快.铵和酸则对HAP的分解起HAP的焓差绝对值低了延迟作用,其分解温度区间△T与纯HAP的相近.含铵HAP的分解峰温与纯HAP的相比延后3HAP热分解反应动力学20K左右,含酸HAP上述特征值延后30K左右.3.1模型方程的建立这可能是由于铵和酸的存在稀释了HAP的浓度,在热重分析中,物质的热分解速率用下式表示从而降低了HAP的起始分解速度,而使得分解峰=k T)/( a)(1)温后移.由于纯HAP的分解是HAP先解离成羟胺和高氯酸,再进一步发生羟胺和高氯酸的氧化分式中a为分解分数,即失重率,其定义式为解,高氯酸的存在使第1步解离反应变得困难,降低了HAP起始分解速度,因此含高氯酸HAP的分式中m0为样品的起始质量,m为样品在T℃时解峰温比含铵HAP的相应值又延后10K左右.此的质量,m;为样品的最终质量.式(1)中,k外,从平均失重速率数据中也可得出上述结论。含(7)为T℃时的速率常数,根据 Arrhenius方程有铁HAP的失重速率比纯HAP快30%,说明铁对k(t)=AeHAP的分解起加速作用;含铵HAP的失重速率与式(1)中的函数f(a)参照质量作用定律,采用纯HAP相近,说明铵只是延迟了HAP的分解,当幂函数形式,在此可写成f(a)=(1-ay,分解发生后,铵基本上对分解无影响;含酸HAP得到的失重速率比纯HAP略低,表明酸对HAP的分解da= Ae E/RT((4)有微弱的阻滞作用在恒定的程序升温速率下B=dT/dt,则(5)Table 1 TG data of samples△a(△t)从上式可求出高氯酸羟胺分解动力学方程式Ta/KT/K(a#)r(1-a)(6)HAP12.95448.09~501.124900.150HAP+NH411.12468,11-521.31510.420.149采用多元线性回归法拟合式(6),便可求出动力学HAP +H5.24477.58-532.37519.910参数HAP+Fe315.47390.48-431.17425.480.195实验中取得的失重速率数据是以dm/dt表示2.2差热分析的,需要转换为da/dt.式(2)两边同时对t微对HAP样品的差热分析结果与热重分析的结分,得到dm/dt果对应性较好,其规律与热重分析类似.样品的差(7)热分析数据见表2.在表2的样品热效应数据中,3.2动力学参数的求解含铁HAP的焓差绝对值最低,这可能是由于它的表3表6分别列出了纯HAP,HAP分解温度较低分解的初级产物没有进一步分解,NHCO, HAP-HCIO2和HAP-FeCl3体系的热分解失重数据Table 2 DTA data of samples中国煤化工方程(6),求得了相△H/k卜g应4CNMHG型参数,归纳于表7HAP498,13699,91其回归的偏差平方和Q<0.152,标准偏差S0.98(含Fe物系偏差稍大)HAP+H'比较4个体系的动力学参数发现,其活化能EHAP+诟方数据18.3432,90477,81和反应级数n的顺序为第51卷第1期米镇涛等:高氯酸羟受热分解动力学135Table 3 Data for neat HAP thermal decomposition by TG and DTGT/Kda( dtda(dt)469.420.085100.07294483.790.3.3060.2528490.530.64590.5.319472.560.11640,09492485,530,38580,31705343450.14890.11779486.950.44500.3858147.410.18488.240,5090,4535493.5179330,498323011739489.650.58330.50889133938482,080.28080.2098Table 4 Data for thermal decomposition of HAP with NH, CIO by TG and DTGda( dtT/Kda( dzT/KT/Ka/n488.580.086270.081766500.350.28750.2179508.570.61320.4365491.160.11581027390.347309.660.67544465493.560.14990.12568504.460.41710.317213511.260.75730.42734496.030.19281534506.220.49150.3736513.190.8323498.090.23330.I805507.380.5495515.140.93780.2016Table 5 Data for thermal decomposition of HAP with HCIO by TG and DTGda( dt/1、da(dtda(dt)T/KT/K01.000.094640.08449513.230.36090.2965519,910.65520.392503.950.13150.12227514.930.42890.3326521.020.71510.3856506.560.17540.1636516.590,49660.3605767019.180.23880.21439517.630.54520.37630.8385.318511.680.31020.2651518.750.59430.3870525,710.89982452Table 6 Data for thermal decomposition of HaP with FeC13 by TG and DTOda( dtda( dtda( dtT/KT/K390.480.0079940,008560414,900.091260,112420,480.26860.666414.660.012730.01189416.650.10990.2209421.120.31517217398.720,019740,01670417,590,12320,3065421,6936100,7630403.060.030630.02342419.100.17960.5002422.310.40810.7966407,470.045350,03474419,960,22670,5990422,830.45040.8162411.610.065510.05285了纯HAP及含有添加物的HAP体系的热分解动力Table 7 parameters of kinetics equations学方程(2)TG和DTA实验结果表明3价铁对HAPHAP0.3783.37×102的分解有促进效果而铵离子和酸对HAP的分解无HAP+H0.9246.14×102促进作用,铵相当于惰性组分酸则对HAP的分解HAP+ F4.07×1020中国煤化工HAP+ FeCl3< HAP< HAP+ NH CIO4 HAP+ HCIOTHaCNMHG明这也反映了4个体系的热安定性顺序A—指前因子min-14结论E—活化能↓mol1H——焓差k1)用方揖G研究了HAP热稳定性得到k—速率常数min化工报2000年2月m—物质质量mgplosives and Propellants(火炸药学报)9982I(2)36-38-反应级数Mueller K F Ciesla M J. US 5223057. 1993R——通用气体常数mol-tK3 Biddle R A Sutton E s US 4527389, 1985T——温度K4 Tian Linxiang(田林祥) Explosives and Propellants(火炸药)1996,194)43-45w—质量分数5 Mishra S C, Pant J, Pant G C Dutta P K, Durgapal U C Propa—失量率nts Explosives Pyrotechnics 995 20 91-956 Goshgarian BB AD 692492. 196B——升温速率℃min17 Cordes H F, Smith SR. J. Inorg. Nucl. Chem., 1970 32(4)下角标1135-1139d—分解f—最终Sinica of USSR Series of Chemistry ,1980171463--1469p——峰值9 Chang Zhihua(常志华). Optimization of Technological Parameter0——起始[ dissertation I学位论文). Tianjin, Tianjin University1998References1 Mi Zhentad米镇涛) Qiu liqin邱立勤). Chinese Journal of ExKINETICS OF THERMAL DECOMPOSITION OFIYDROXYLAMINE PERCHLORATEMi Zhentao Chang Zhihua, Zhang Xiangwen, Qiu Liqin and Wang YaquanSchool of Chemical Engineering and Technology, Tianjin University Tianjin 300072)Abstract Hydroxylamine perchlorate( HaP )is a new energetic oxidizer. The thermal decomposition of pureHAP and the effects of additives on thermal decomposition of HaP were studied by using TG and DTA in nitrogen atmosphere. The additives are 4.0%NH4CIO4,3.0%HCIO4 and 0. 29% FeCl respectively. The TGcurves of the above four systems were determined. The experimental results indcate that FeCl, has a promotingeffect on the decomposition of hap but NH CIO4 and HClO4 have no such effect on the decomposition of HAPNH4CIO4 acts as an inert substance and HCIO4 has a weak retarding effect on the decomposition of haP, busing non-isothermal TG-DTG the thermal decomposition kinetic equations of the four systems were obtainedThrough comparing the kinetic parameters of the four systems ,the order of decomposition activation energy (eand reaction order( n )were foundHAP +0. 29% FeCl3< HAP< HAP+ 4.0%NH, CIO4 HAP +3.0%HCIOThis also indicates the order of thermal stability of the four systems. The thermal decomposition data of dtashow that the decomposition heat of HAP is-69991 kf g and the decomposition peak temperature of HAPis 498 13K. With the decomposition peak temperature of HAP FeCl3to 432 90K, the ones of hap tNH CIO4 and HAP+ HCIO4 increase to 520.03 K and 532.90 K respectivelyKeywords hydroxylamine perchlorate decomposition kinetics中国煤化工CNMHGTo whom correspondence should be addressed