偶氮及氧化偶氮呋咱化合物的合成与表征

以3,4-二氨基呋咱(DAF)为原料,次氯酸钠为氧化剂合成出3,3′-二氨基-4,4′-偶氮呋咱(DAAF);用相对较强的氧化剂过硫酸氢钾的复合盐(OXONETM)氧化DAF得到3,3′-二氨基-4,4′-氧化偶氮呋咱(DAOAF);以100%硝酸为硝化剂硝化DAAF制得3,3′-二硝氨基-4,4′-偶氮呋咱(DNAAF);DAAF和DAOAF分别经重氮化叠氮取代得到3,3′-二叠氮基-4,4′-偶氮呋咱(DADAF)和3-氨基-3′-叠氮基-4,4′-氧化偶氮呋咱(AAAF);DADAF久置一段时间完全转化成5-[4-叠氮基呋咱基]-5H-[1,2,3]三唑并[4,5-c][1,2,5]呋咱内盐(I)。采用红外、质谱、核磁等分析手段对所合成化合物进行表征。     

3,4-二(4′-氨基-3′,5′-二硝基苯基)氧化呋咱的合成及热性能

以4-甲氧基苯腈为原料,经肟化、重氮化、脱氮、关环、硝化及胺化等六步反应合成3,4-二(4′-氨基-3′,5′-二硝基苯基)氧化呋咱(DANBF),并优化了肟化、氧化呋咱成环及硝化反应的条件,用DSC、TG等对目标化合物的热性能进行了表征。结果表明,氧化呋咱成环反应的最适宜条件为:Na2CO3摩尔量为理论摩尔量的1.35倍,反应温度2～10℃,反应时间5h,收率58.1%,纯度不小于99.0%(HPLC)。芳基取代的氧化呋咱化合物具有较好的热稳定性。     

新型含能材料呋咱类化合物的研究进展

介绍了几种呋咱类含能化合物3,4–二氨基呋咱(DAF)、3,3′–二氨基–4,4′–氧化偶氮呋咱(DAAF)、3,3′–二氨基–4,4′–偶氮呋咱(DAAzF)、3,4–二硝基呋咱基氧化呋咱(DNTF)、3–硝基呋咱–4–甲醚(NFME)、(3 E,4 E)–二肟甲基氧化呋咱(DPX1)的合成方法和性能。通过与其他含能材料的性能对比,可知呋咱类化合物是一类性能优良、具有广阔应用前景、可应用于推进剂的含能材料。     

3-氨基-4-(叔丁基氧化偶氮基)呋咱的合成与表征

以3,4-二氨基呋咱(DAF)为起始原料,苯为反应介质,经Caro’s酸氧化得到3-氨基-4-亚硝基呋咱,然后与N,N-二溴-叔丁基胺缩合得到标题化合物,总收率37.6%,并采用红外光谱、核磁共振、元素分析及质谱等进行了结构表征。优化了反应条件,确定适宜的反应条件为:氯化亚铜作为催化剂,反应时间16 h,温度15～25℃,收率73.5%。     

呋咱含能化合物的合成及其衍生物反应研究进展

阐述了二肟脱水和氧化呋咱还原2种构建呋咱环的主要方法,以及氨基取代呋咱衍生物、硝基取代呋咱衍生物和氰基取代呋咱衍生物的反应;列举了几种典型的呋咱含能化合物如二硝基呋咱(DNF)、二氨基偶氮呋咱(DAAF)、3,4–双(4′–硝基呋咱–3′–基)氧化呋咱(DNTF)、呋咱醚类化合物(FOF–1,FOF–2,FOF–13)和稠环类呋咱含能化合物(MNOTO、4,5,9,10–四硝基–1,4,5,8–四氮杂氢化萘(2,3,–6,7)并双呋咱)的合成方法及性能。     

3,4-二(4'-氨基-3',5'-二硝基苯基)氧化呋咱的合成及热性能

以4-甲氧基苯腈为原料,经肟化、重氮化、脱氮、关环、硝化及胺化等六步反应合成3,4-二(4'-氨基-3',5'-二硝基苯基)氧化呋咱(DANBF),并优化了肟化、氧化呋咱成环及硝化反应的条件,用DSC、TG等对目标化合物的热性能进行了表征.结果表明,氧化呋咱成环反应的最适宜条件为:Na2CO3摩尔量为理论摩尔量的1.35倍,反应温度2～10℃,反应时间5h,收率58.1％,纯度不小于99.0％(HPIC).芳基取代的氧化呋咱化合物具有较好的热稳定性.     

几种呋咱类含能化合物的合成、热行为及理论爆轰性能预估

用双氧水、钨酸钠及甲磺酸氧化3,4-二氨基呋咱(DAF)合成了3-氨基-4-硝基呋咱;用100%硝酸硝化DAF得到3,4-二硝胺基呋咱;用NaNO_2、H_2SO_4及NaN_3DAF重氮、取代DAF得到3-氨基-4-叠氮基呋咱;用30%的双氧水、钨酸钠及甲磺酸氧化3-氨基-4-叠氮基呋咱,得到3-叠氮基-4-硝基呋咱及3,3′-二叠氮基-4,4′-氧化偶氮呋咱。用TG-DSC研究了这些化合物的热行为。采用B3LYP/6-31G*方法预估了化合物的理论密度、标准生成、爆速、爆压。结果表明,氧化偶氮基的引入增强了呋咱类化合物的热稳定性;叠氮基的引入提高了化合物的生成焓。3-氨基-4-硝基呋咱中氨基转化为叠氮基,生成焓由183.26kJ/mol增至571.40 kJ/mol;硝胺基的引入显著提高了含能化合物的密度、爆速和爆压。     

苦基呋咱醚化合物的合成及表征

为了得到综合性能优良的高能量密度材料,通过将羟基硝基呋咱转化为相应的醇钠盐,分别与苦基氯（PcCl）和2,4-二氯-1,3,5-三硝基苯（DCPc）缩合得到苦基-（3-硝基呋咱基-4）醚（FOP）和双（3-硝基呋咱基-4）苦基醚（DFOP）,采用红外光谱、核磁共振、质谱及元素分析方法对其结构进行了表征。确定了最佳合成条件,FOP合成条件为：PcCl与硝基呋咱醇钠的摩尔比1．0：1．1,反应温度80℃,反应时间16h,以原料PcCl计产品收率达到31％以上;DFOP合成条件为：DCPc与硝基呋咱醇钠的摩尔比1．0：2．7,反应温度80℃,反应时间2h,以原料DCPc计产品收率达到42％以上。     

3-氨基-4-氰基呋咱（CNAF）的合成及表征

以丙二腈为原料,一步法合成了3-氨基-4-酰氨肟基呋咱(AAOF),然后用过氧化铅氧化得到了标题化合物,利用IR、1HNMR、13CNMR、元素分析进行结构表征,并确定最佳氧化反应条件:冰乙酸与AAOF的物质的量比为9:1,过氧化铅与AAOF的物质的量比为1:1,时间为1.5 h,温度为30～35℃,收率达到71.4%,高于文献报道(54%);初步探索自行设计的CNAF分步合成路线,并从理论上分析3-氨基-2,3-二肟基丙腈未能脱水环化得到CNAF的原因.     

N,N’-二硝基-N,N’-二(3-([1,2,3]-三唑并[4,5-c]呋咱-4,5-内盐-5-基)呋咱-4-基)二氨基甲烷的合成与表征

以二氨基呋咱(DAF)为起始原料,经Caro's acid氧化、锌粉还原、环化、缩合和硝化五步反应得到N,N’-二硝基-N,N ’-二(3-([1,2,3]-三唑并[4,5-c]呋咱-4,5-内盐-5-基)呋咱-4-基)二氨基甲烷(MNOTO),总收率为32.7％(以DAF计).用元素分析、核磁共振、红外光谱等进行了结构表征.用浓硝酸和醋酐作为硝化体系硝化N,N’-二(3-([1,2,3]-三唑并[4,5-c]呋咱-4,5-内盐-5-基)呋咱-4-基)二氨基甲烷(MAOTO),考察了反应温度、反应时间以及浓硝酸与醋酐摩尔比对反应收率的影响,硝化体系中硝酸和醋酐的最佳摩尔比为1.5∶1,反应温度15～20℃,反应时间为5h.     

在Pt／Al2O3催化剂上气相苯加氢反应的动力学

在研制得到了高活性和高选择性 Pt/Al_2O_3催化剂的基础上,采用微反-色谱联用装置考察了气相苯加氢反应的动力学。假定在催化剂表面上存在着两种不同的活性中心,一种吸附氧;另一种吸附苯、环己烷及反应中间物,并假定吸附氢与吸附苯间的表面反应为过程的控制步骤,从而导出动力学方程。通过实验测得了不同反应条件下的反应速率和组分分压,并用非线性回归方法处理实验数据,求得方程中各参数。通过偏差分析、方差分析及 Boudart 提出的四条判断准则,验证了动力学模型及回归参数的合理性。结果得到了此动力学模型与实验数据较好地吻合。在此基础上测定了反应的活化能及氢、苯和环已烷的吸附热。     

Kinetic parameters estimation for cure reaction of epoxy based vinyl ester resin

A new graphical estimation technique is proposed for the determination of the kinetic parameters describing an autocatalytic reaction. A differential scanning calorimeter was used to monitor the reaction kinetics of an epoxy-based vinyl ester resin. The method utilizes information from a zero initial reaction rate, conversation at vitrification, the ratio of reaction rate constants under different isothermal conditions, and characteristics of the phenomenological kinetic model with assumptions being made about the overall reaction order. By fitting data to the integrated reaction rate equation with adjustments for the isothermal conditions, the kinetic parameters are estimated without using a linear or nonlinear regression method. Different kinetic parameters can be estimated from data before and after the gel point which was obtained from the relationship between the glass transition temperature and the degree of cure.     

Hemicellulose Hydrolysis in the Presence of Heterogeneous Catalysts

A prominent autocatalytic effect in the hydrolysis of hemicelluloses was observed in the presence of heterogeneous cation-exchange catalysts, Amberlyst 15 and Smopex 101. The kinetic models proposed were based on the reactivities of the non-hydrolysed sugar monomer units and the increase of the rate constant as the reaction progresses and the degree of polymerization decreases. General kinetic models were derived and the kinetic parameters, describing the autocatalytic effect, were determined by non-linear regression analysis. The kinetic model explained very well the overall kinetics, as well as the product distribution in the hydrolysis of hemicelluloses.     

Hemicellulose Hydrolysis in the Presence of Heterogeneous Catalysts

A prominent autocatalytic effect in the hydrolysis of hemicelluloses was observed in the presence of heterogeneous cation-exchange catalysts, Amberlyst 15 and Smopex 101. The kinetic models proposed were based on the reactivities of the non-hydrolysed sugar monomer units and the increase of the rate constant as the reaction progresses and the degree of polymerization decreases. General kinetic models were derived and the kinetic parameters, describing the autocatalytic effect, were determined by non-linear regression analysis. The kinetic model explained very well the overall kinetics, as well as the product distribution in the hydrolysis of hemicelluloses.

     

基于无模式法推断石灰石分解机理新方法

提出一种基于无模式法推断反应机理函数的新方法。首先分析反应发生的过程,对机理函数作初步筛选;然后采用Popescu法通过函数拟合的线性相关度对机理函数作进一步的推断;最后采用单个扫描速率的微分法与等转化率法相结合的方法,以活化能为判据确定最概然机理函数。此方法可以从根本上消除动力学补偿效应的影响,而且计算过程中几乎没有作任何假设和近似处理,多重扫描速率法也可以减小微分计算所带来的误差。以活化能作为反应机理最终的判据,可以对机理函数进行明显的区分,避免了仅依赖函数拟合线性的微小差别进行判断的问题。因此,此方法得到的结果是可靠的。采用热重分析技术对3种石灰石分解反应进行研究,结果表明相界面反应控制的收缩圆柱体模型是石灰石分解的最概然机理函数,进一步证明了此方法的可行性。     

连续结晶器中十水草酸铈反应结晶动力学研究

采用连续稳态法,对十水草酸铈在混合悬浮、混合产品排出(MSMPR)结晶器中的连续反应结晶动力学进行了研究。实验测定了十水草酸铈晶体的粒数密度分布数据,并以此为基础,基于粒度无关生长速率模型,对不同实验条件下晶体的粒数密度分布数据进行拟合,确定了十水草酸铈的成核动力学方程和生长动力学方程,并计算得到十水草酸铈晶体的成核、生长速率相对于过饱和度的指数分别为4.211和0.752。同时,对方程的理论分析表明,低过饱和度有利于得到平均粒径更大的十水草酸铈晶体。十水草酸铈结晶动力学的研究,为其大规模工业生产提供了重要的动力学数据。     

Rubber modified epoxy resin. I: Cure kinetics and chemorheology

The curing and vitrification effect during the reaction of ATBN modified epoxy resin was studied through the dynamic differential scanning calorimetry method and a new reaction kinetic equation containing generalized WLF equation was developed to describe the reaction rate at both glassy and rubbery state. An autocatalytic mechanism was found to describe adequately the cure kinetics of the rubber modified epoxy resin and the overall order of reaction was assumed to be 2. The kinetic parameters were determined from the DSC data through the Marquardt's multivariable nonlinear regression method and Runge–Kutta integration technique. The presence of rubber indicated minor effect on the cure kinetics of epoxy resin. The Arrhenius type viscosity function was employed to establish a relationship between viscosity data measured by RMS and chemical conversion calculated from the reaction kinetic equation.     

Kinetics of epoxidation of jatropha oil with peroxyacetic and peroxyformic acid catalysed by acidic ion exchange resin

The kinetics of epoxidation of jatropha oil by peroxyacetic/peroxyformic acid, formed in situ by the reaction of aqueous hydrogen peroxide and acetic/formic acid, in the presence of an acidic ion exchange resin as catalyst in or without toluene, was studied. The presence of an inert solvent in the reaction mixture appeared to stabilise the epoxidation product and minimise the side reaction such as the opening of the oxirane ring. The effect of several reaction parameters such as stirring speed, hydrogen peroxide-to-ethylenic unsaturation molar ratio, acetic/formic acid-to-ethylenic unsaturation molar ratio, temperature, and catalyst loading on the epoxidation rate as well as on the oxirane ring stability and iodine value of the epoxidised jatropha oil were examined. The multiphase process consists of a consecutive reaction, acidic ion exchange resin catalysed peroxyacid formation followed by epoxidation. The catalytic reaction of peroxyacetic/peroxyformic acid formation was found to be characterised by adsorption of only acetic (or formic) acid and peroxyacetic/peroxyformic acid on the active catalyst sites, and the irreversible surface reaction was the overall rate determining step. The proposed kinetic model takes into consideration two side reactions, namely, epoxy ring opening involving the formation of hydroxy acetate and hydroxyl groups and the reaction of the peroxyacid and epoxy group. The kinetic and adsorption constants of the rate equations were estimated by the best fit using nonlinear regression method. Good agreement between experimental and predicted data validated the proposed kinetic model. From the estimated kinetic constants, the apparent activation energy for epoxidation reaction was found to be 53.6 kJ/mol. This value compares well with those reported by other investigators for the same reaction over similar catalysts.     

Cure kinetics of epoxy resin used for advanced composites

The cure kinetics of an epoxy resin used for the preparation of advanced polymeric composite structures was studied by isothermal differential scanning calorimetry (DSC). A series of isothermal DSC runs provided information about the kinetics of cure over a wide temperature range. According to the heat evolution behavior during the curing process, several influencing factors of isothermal curing reactions were evaluated. The results showed that the isothermal kinetic reaction of this epoxy resin followed an autocatalytic kinetic mechanism. In the latter reaction stage, the curing reaction became controlled mainly by diffusion. Cure rate was then modeled using a modified Kamal autocatalytic model that accounts for the shift from a chemically controlled reaction to a diffusion‐controlled reaction. The model parameters were determined by a nonlinear multiple regression method. Copyright © 2004 Society of Chemical Industry     

NO2氧化二甲基硫醚动力学研究

采用连续釜式反应器，对NO2氧化二甲基硫醚生成二甲基亚砜的反应进行了实验研究。在假定反应步骤和考虑二甲基亚砜对二氧化氮溶解度影响的前提下，建立了反应的动力学模型，并结合实验数据，对动力学模型进行了参数估值。经统计检验表明，所建立的动力学模型是适当的。