3,3’-二硝氨基-4,4’-氧化偶氮呋咱羟胺盐的热行为和热安全性研究（英文）

利用C500量热仪研究了3,3′-二硝氨基-4,4′-氧化偶氮呋咱羟胺盐(HNAF)的热分解特性,根据Kissinger和Ozawa方程计算了热分解的动力学参数,同时计算了热分解的热力学参数;采用Micro-DSCⅢ量热仪测定了3,3′-二硝氨基-4,4′-氧化偶氮呋咱羟胺盐的比热容,计算获得了3,3′-二硝氨基-4,4′-氧化偶氮呋咱羟胺盐热安全评价参数。结果表明,HNAF的活化能(E)和指前因子(A)分别为205.26 kJ/mol和1020.32 s-1;活化熵、活化焓和活化吉布斯自由能分别为140.76 J/(mol·K)、201.56 kJ/mol和200.39 kJ/mol。比热容方程与298.15 K时的摩尔比热容分别为C p=-1.560+0.016 T-2.263×10-5 T 2(J/(g·K))和446.028 J/(mol·K)。自加速分解温度、绝热分解温升、热爆炸临界温度分别为444.44 K、2382.89 K、452.86 K,绝热至爆时间为12.46~12.54 s。     

3,4–二(4'–氯–3'–硝基苯–1'–基)氧化呋咱的合成及热性能

以4–氯苯腈(CCB)为原料,经肟化、重氮化–氯化、缩合环化、硝化多步反应设计并合成了一种新型氧化呋咱化合物——3,4–二(4'–氯–3'–硝基苯–1'–基)氧化呋咱(DCNBF),采用红外、核磁共振、质谱及元素分析等表征方法鉴定了目标物与中间体的结构,确定了肟化和环化反应的较佳合成条件;采用差示扫描量热、热重等热分析方法研究了目标化合物的热性能。     

3,3'-二硝氨基-4,4'-氧化偶氮呋咱羟胺盐的热行为和热安全性研究（英文）

利用C500量热仪研究了3,3′-二硝氨基-4,4′-氧化偶氮呋咱羟胺盐(HNAF)的热分解特性,根据Kissinger和Ozawa方程计算了热分解的动力学参数,同时计算了热分解的热力学参数;采用Micro-DSCⅢ量热仪测定了3,3′-二硝氨基-4,4′-氧化偶氮呋咱羟胺盐的比热容,计算获得了3,3′-二硝氨基-4,4′-氧化偶氮呋咱羟胺盐热安全评价参数。结果表明,HNAF的活化能(E)和指前因子(A)分别为205.26kJ/mol和1020.32s~(-1);活化熵、活化焓和活化吉布斯自由能分别为140.76J/(mol·K)、201.56kJ/mol和200.39kJ/mol。比热容方程与298.15K时的摩尔比热容分别为C_p=-1.560+0.016T-2.263×10~(-5)T~2(J/(g·K))和446.028J/(mol·K)。自加速分解温度、绝热分解温升、热爆炸临界温度分别为444.44K、2382.89K、 452.86K,绝热至爆时间为12.46～12.54s。     

3,4-双(4'-氨基呋咱基-3')氧化呋咱的合成及性能

以丙二腈为起始原料,经亚硝化、重氮化、缩合等反应合成出3,4-双(4′-氨基呋咱基-3′)氧化呋咱(DATF),总收率为50%.经测定,DATF的部分理化及爆轰性能为: 密度1.795 g/cm3,熔点170～171 ℃,爆速7 177 m/s(1.530 g/cm3),热分解温度260 ℃,摩擦感度8%(90°摆角),撞击感度60%(10 kg,25 cm),真空安定性(5 g样品,100 ℃,48 h),放气量0.4～0.7 mL.采用差热扫描(DSC)法,测定了DATF的热稳定性及DATF同NC,RDX,HMX和NC/NG体系的相容性.结果表明,DATF具有较好的热稳定性和较低的感度,与RDX,HMX,NC和NC/NG体系有较好的相容性.     

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-双(4′-氨基呋咱基-3′)氧化呋咱的合成及性能

以丙二腈为起始原料,经亚硝化、重氮化、缩合等反应合成出3,4-双(4′-氨基呋咱基-3′)氧化呋咱(DATF),总收率为50%。经测定,DATF的部分理化及爆轰性能为:密度1.795g/cm3,熔点170~171℃,爆速7177m/s(1.530g/cm3),热分解温度260℃,摩擦感度8%(90°摆角),撞击感度60%(10kg,25cm),真空安定性(5g样品,100℃,48h),放气量0.4~0.7mL。采用差热扫描(DSC)法,测定了DATF的热稳定性及DATF同NC,RDX,HMX和NC/NG体系的相容性。结果表明,DATF具有较好的热稳定性和较低的感度,与RDX,HMX,NC和NC/NG体系有较好的相容性。     

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。     

3，4-二硝基呋咱基氧化呋咱在N-甲基-2-吡咯烷酮和二甲基亚砜中的溶解行为

在常压、298.15K条件下,用RD496-2000微热量仪分别测量3,4-二硝基呋咱基氧化呋咱(DNTF)在N-甲基-2-吡咯烷酮(NMP)和二甲基亚砜(DMSO)中的溶解焓,得到DNTF在不同溶剂中的微分溶解热和积分溶解热,建立了热量与溶质的量之间的关系式.对于DNTF,在NMP中描述溶解过程的动力学方程为dα/dt=10~(-3.81)(1-α)~(1.19);在DMSO中,描述溶解过程的动力学方程为dα/dt=10~(-3.91)(1-α)~(0.88.)     

3,4-二氨基呋咱基氧化呋咱合成的反应动力学模型

以3-氨基-4-酰胺肟基呋咱为原料合成了3,4-二氨基呋咱基氧化呋咱,考察了反应体系中反应物浓度、温度和反应时间对反应速率的影响。通过ChemCAD速率回归计算程序对实验数据进行回归计算,并将速率方程进行线性化处理,得到反应级数、反应活化能和频率因子,建立了3,4-二氨基呋咱基氧化呋咱合成反应的动力学模型,计算值与实验值的相对误差均小于1%,说明动力学方程及动力学参数与3,4-二氨基呋咱基氧化呋咱的反应动力学行为相吻合。从反应动力学模型得出,降低反应温度、提高起始原料AAOF浓度、降低硫酸浓度、采用分批加入硫酸的间歇操作方式都可抑制副反应的发生,提高目标产物的转化速率和选择性。     

苦基呋咱醚化合物的性能预估

为得到综合性能优良的高能量密度材料,设计了氧桥苦基呋咱系列化合物苦基-(3-硝基呋咱基-4)醚(FOP)、双(3-硝基呋咱基-4)苦基醚(DFOP)和叁(3-硝基呋咱基-4)苦基醚(TFOP).采用B3LYP/6-31G方法、Kamlet公式及H50经验公式对3种化合物进行了密度、生成焓、爆轰性能及稳定性预估.结果表明,硝基呋咱单元的引入可以大大提高钝感苦基类化合物的密度、生成焓及爆轰性能;苦基的引入可以提高呋咱类化合物的稳定性.     

Thermal control in graphene nanoribbons: thermal valve, thermal switch and thermal amplifier

We study the thermal transport in graphene nanoribbons by using nonequilibrium molecular dynamics simulations. It is reported that the three-terminal graphene nanoribbons can perform some functions of thermal devices such as thermal valve, thermal switch and thermal amplifier. Electronic devices have transformed almost all aspects of our lives. It has not escaped our attention that the graphene nanoribbons we have presented here may have similar surprising applications in devices that allow the flow of heat to be controlled in a short future.     

Rapid thermal cycling with low thermal inertia tools

Solid freeform fabrication processes offer the manufacturing flexibility for tools with low thermal inertia and internal conformal channels for rapid thermal cycling in injection molding. This article analyzed each step of a rapid thermal cycling process and provided quantitative guidance for tooling design. The proposed design methodology was tested on a three‐dimensional (3D) printed benchmark tool with truss support. Rapid cooling test on the benchmark tool resulted in the mold time constant shorter than 2.3 s and the cavity temperature uniformity better than 3°C. Preliminary tests demonstrated the technical feasibility of using a solid freeform fabrication process to fabricate low thermal inertia tools for improved heat management in injection molding. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers     

Effect of TGO thickness on the thermal barrier coatings life under thermal shock and thermal cycle loading

Effect of thermally grown oxide (TGO) thickness on thermal shock resistance of thermal barrier coatings (TBCs) and also their behavior under a cyclic loading (including aging at maximum temperature) was evaluated experimentally. In order to form different thicknesses of TGO, coated samples experience isothermal loading at 1070?°C for various periods of times. Heat-treated samples were heated to 1000?°C and cooled down rapidly in water from the substrate side using a mechanical fixture. The life of samples was investigated as a function of TGO thickness. Furthermore, by performing an experiment the simultaneous effect of the TGO growth and thermal expansion mismatch– on the failure of thermal barrier coatings was evaluated. The results demonstrated that the presence of TGO with a thickness of 2–3?µm has a positive effect on the resistance against thermal shock.     

新型相变蓄热材料的热物性测试

为了寻找新型相变蓄热材料,对不同配比下NaCl/KCl/MgCl2三元体系的熔点进行了测量,提出了一种新型三元相变蓄热材料质量分数之比为20%NaCl/20%KCl/60%MgCl2;搭建了准稳态法测试试验台,并利用试验台对新型三元相变蓄热材料的主要热物性参数,包括比热、导热系数和熔解热进行了测试。测定温度范围61.21—573.65℃;利用多项式函数对导热系数和比热试验数据进行了拟合,拟合平均相对偏差小于1.5%。试验结果表明,新型相变蓄热材料潜热大、蓄热密度高、且具有较高的导热系数,具有广阔的工程应用前景。     

介孔复合材料内界面热阻及热导率

界面广泛存在于复合材料中,对介孔复合材料热物性起着决定性的影响,研究界面的导热特性对于认识和理解介孔复合材料的导热机制十分重要。利用非平衡的分子动力学模拟方法计算介孔复合材料中基材与填充物间的界面热阻,考察界面热阻随温度、材料质量差异的变化,进一步用界面热阻修正介孔复合材料的有效热导率。结果表明,界面热阻的数量级为10^-11m²·K·W^-1,并随温度升高逐渐降低。界面两端材料质量差异越大,界面热阻越高。可通过减小孔径、减小纳米线长度、增大纳米线间距、降低纳米线填充率来降低介孔复合材料的有效热导率。界面热阻能降低材料的有效热导率。孔径越小、纳米线间距越小、纳米线长度越长、填充率越高,界面热阻降低热导率效果越显著。     

High thermal conductive epoxy molding compound with thermal conductive pathway

The epoxy molding compound (EMC) with thermal conductive pathways was developed by structure designing. Three kinds of EMCs with different thermal conductivities were used in this investigation, specifically epoxy filled with Si₃N₄, filled with hybrid Si₃N₄/SiO₂, and filled with SiO₂. Improved thermal conductivity was achieved by constructing thermal conductive pathways using high thermal conductivity EMC (Si₃N₄) in low thermal conductivity EMC (SiO₂). The morphology and microstructure of the top of EMC indicate that continuous network is formed by the filler which anticipates heat conductivity. The highest thermal conductivity of the EMC was 2.5 W/m K, reached when the volume fraction of EMC (Si₃N₄) is 80% (to compare with hybrid Si₃N₄/SiO₂ filled‐EMC, the content of total fillers in the EMC was kept at 60 vol %). For a given volume fraction of EMC (Si₃N₄) in the EMC system, thermal conductivity values increase according to the order EMC (Si₃N₄) particles filled‐EMC, hybrid Si₃N₄/SiO₂ filled‐EMC, and EMC(SiO₂) particles filled‐EMC. The coefficient of thermal expansion (CTE) decreases with increasing Si₃N₄ content in the whole filler. The values of CTE ranged between 23 × 10^?6 and 30 × 10^?6 K^?1. The investigated EMC samples have a flexural strength of about 36–39 MPa. The dielectric constant increases with Si₃N₄ content but generally remains at a low level (<6, at 1 MHz). The average electrical volume resistivity of the EMC samples are higher than 1.4 × 10¹⁰ Ω m, the average electrical surface resistivity of the EMC samples are higher than 6.7 × 10¹⁴ Ω. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Measurements of the thermal conductivity and thermal diffusivity of polymers

In this paper, the thermal conductivity and thermal diffusivity of nine polymers were measured by using the transient short‐hot‐wire method. The corresponding specific heat was measured with a commercial Differential Scanning Calorimeter (DSC). The effects of temperature on the thermal conductivity, thermal diffusivity, and the product of density and specific heat are further discussed. The results show that the transient short‐hot‐wire method can be used to measure the thermal conductivity, thermal diffusivity, and the product of density and specific heat of polymers within uncertainties of 3%, 6%, and 9%, respectively.     

Solution precursor thermal spraying of gadolinium zirconate for thermal barrier coating

Gadolinium zirconate (GZ) is an attractive material for thermal barrier coatings (TBCs). However, a single layer GZ coating has poor thermal cycling life compared to Yttria Stabilized Zirconia (YSZ). In this study, Solution Precursor High Velocity Oxy-Fuel (SP-HVOF) thermal spray was used to produce a double layer GZ/YSZ TBC and compared the thermal cycling performance with the single layer YSZ TBC. The temperature behaviour of the solution precursor GZ was studied, and single splat tests were carried out to obtain an optimised spray parameter. In thermal cycling tests, the single-layer YSZ reached 20 % failure at 85 ± 5 cycles, whereas the double-layer GZ/YSZ was at 70 ± 15 cycles. The single-layer failed at the topcoat/TGO interface, whereas the double-layer failed at GZ/YSZ interface and topcoat/TGO interface. Moreover, Gd diffusion occurred near the GZ/YSZ interface, resulting in porosities in the GZ layer.     

二氧化碳水合物导热和热扩散特性

热导率和热扩散率是天然气水合物资源开采关键性基础热物性数据,采用反应釜内壁衬有氟塑料材料,低过冷度,让水合物在反应釜内逐层生成的合成方法,获得可直接用于导热测试的二氧化碳水合物样品。采用瞬变平面热源法原位测试了温度264.68～282.04 K、压力1.5～3 MPa二氧化碳水合物热导率、热扩散率,并测试了二氧化碳水合物在268.05 K、0.6 MPa左右发生自保护效应过程中热导率、热扩散率,获得了晶态下和自保护效应过程中的二氧化碳水合物热导率、热扩散率变化特性。测试结果将为天然气水合物资源的开发利用提供基础数据和理论依据。