CHINESE CHEMICAL LETTERS
·
2011
·Vol. 22
·期 12
·1497-1500
·
IF 0.775
Xiao Zheng Lan,Hai Rong Pei,Chuan Xian Cheng
Phase behavior of binary system of bromobenzene–chlorobenzene (C 6 H 5 Br–C 6 H 5 Cl) confined in SBA-15 and MCM-41 (pore diameter 8 nm, 3.8 nm, respectively) has been investigated by means of differential scanning calorimetry (DSC). Phase diagram of C 6 H 5 Br–C 6 H 5 Cl system confined in SBA-15 is a type of the complete miscible both in liquid and solid state, the same phase behavior as the bulk system. However, the phase diagram comprises only one boundary line, which is shifted down 22–36 K with respect to the bulk system. C 6 H 5 Br, C 6 H 5 Cl or the mixture within nanopores of MCM-41 is nonfreezing. The different phase behavior of the system confined in SBA-15 and MCM-41 is thought mainly due to the relative size of pore to molecule.
研究领域:
物理化学
·
材料科学
·
纳米科技
·
热力学
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DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2016
·Vol. 31
·期 1
·157-163
·
IF 0.4
Liu Rongpeng,Wan Liqiang,Huang Farong,Du Lei
The reaction kinetics between diazide(4,4’-biphenyl dibenzyl azide) and different diynes (dipropargyl bisphenol A and 1,3-diethynylbenzene) were studied by means of differential scanning calorimetry (DSC) and nuclear magnetic resonance spectroscopy ( 1 H-NMR). DSC was adopted to analyze the reactions under bulk polymerization condition, while 1 H-NMR for solution reaction polymerization was conducted. The apparent activation energies ( E
α ) calculated by Kissinger’s method were 77.96, 81.24 kJ/mol, which were confirmed by Friedman’s method, and 65.45, 69.36 kJ/mol by 1 H-NMR for dispropargyl bisphenol A/4,4’-biphenyl dibenzyl azide and 1,3-diethynylbenzene/4,4’-biphenyl dibenzyl azide, respectively. The polymerizations between the diazide and diynes were first-order reactions based on calculation from both DSC and 1 H-NMR. The results showed that the reaction between dipropargyl bisphenol A and 4,4’-biphenyl dibenzyl azide was easier than that between 1,3-diethynylbenzene and 4,4’-biphenyl dibenzyl azide, verifying that the reactivity of aliphatic alkyne was higher than that of aromatic alkyne.
研究领域:
高分子化学
·
物理化学
·
材料科学
·
有机化学
·
反应动力学
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DOI
高影响因子
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
·
2021
·Vol. 647
·期 6
·681-685
·
IF 1.492
Xieyang Wang,Zhen Dong,Rui Yang,Shengren Zhou,Zhiwen Ye
Two energetic salts of cyclo-N 5 − , O-methylisoure pentazolate ( 1 ) and guanidinoacetic acid pentazolate ( 2 ), were synthesized by metathesis reaction. All the energetic cyclo-N 5 − salts were characterized by single-crystal XRD, IR spectroscopy, 1 H and 13 C multinuclear NMR spectroscopy, thermal analysis (DSC) and elemental analysis. They exhibit good thermal stability with decomposition temperatures of more than 100 °C and they are in excellent agreement with those reported non-metallic salts. Salt 1 also exhibits strong π-π interactions. The standard enthalpies of formation and detonation performances of these salts were calculated using Gaussian 09 and EXPLO5 v6.01 programs. The detonation velocities of compound 1 and 2 are both about 7400 m s −1 and these two salts exhibit low mechanical sensitivity (IS>23 J, FS>220 N). Therefore, in this work, the synthesis of the new pentazolate salts enriches the cyclo-pentazolate salts system, which is conducive to the exploration of more heat-resistant and higher detonation velocities pentazolate salts.
研究领域:
无机化学
·
含能材料
·
热分析
·
结构化学
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DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2016
·Vol. 28
·期 1
·49-54
·
IF 1.947
Qi-Feng Li,Chao Wang,Xiao-Zheng Lan
Latent heat storage performance of a layered perovskite-type compound, 1-C 14 H 29 NH 3 ) 2 ZnCl 4 (C 14 Zn), embedded in a series of silica gel (SG) with pore sizes of d = 15–200 nm is investigated using differential scanning calorimetry (DSC), and powder X-ray diffractions (XRD). C 14 Zn in the nanopores of silica gel shows size-dependent phase transition temperature, enthalpy change and supercooling. They have a stable transition temperature and heat capacity at each size in a short-term thermal cycling. Similar X-ray diffraction patterns are observed for the nano-sized and the bulk C 14 Zn. The encapsulation of a phase change material in nanopores is a new way of tuning its thermal energy storage properties for a wider range of temperature regulation.
研究领域:
材料科学
·
热力学
·
纳米科技
·
能源存储
·
功能材料
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DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2011
·Vol. 110
·期 3
·1437-1442
·
IF 1.752
Lan X. Z.,Pei H. R.,Yan X.,Liu W. B.
Phase behavior of dodecane–tetradecane ( n -C 12 H 26 –C 14 H 30 , n -C 12 –C 14 ) binary system in bulk and confined in SBA-15 (pore diameters 8 nm; 15.9 nm) has been investigated by differential scanning calorimetry and transmission electron microscopy. The bulk system possesses some special phases relating to the rotator phase in normal alkanes. Dodecane–tetradecane mixtures confined in SBA-15 (8 nm) are a system miscible both in solid and liquid states with a phase diagram of a smooth curve. Dodecane–tetradecane system confined in SBA-15 (15.9 nm) exhibits not only solid–liquid (s–l) in all compositions but solid–solid transition in mole fractions of tetradecane 0.1–0.6, which forms a phase diagram of “loop line” shape. Melting temperatures of n -C 12 –C 14 /SBA-15 (8 nm) are lower than those of n -C 12 –C 14 /SBA-15 (15.9 nm) in all mole fractions. The evolution of the phase diagram of n -C 12 –C 14 confined in 8 nm, 15.9 nm pore sizes of SBA-15 and in bulk, respectively, shows a dramatic effect of confinement on phase behavior of normal alkane mixtures. The s–l phase boundary lines of n -C 12 –C 14 /SBA-15 (8, 15.9 nm) are fitted as \( T_{\text{m,r}}^{x} \) being [ \( xT_{{\text{m} ,r}}^{A} + \left( {1 - x} \right)T_{\text{m,r}}^{B} - D \) ], where D is a polynomial ∑ a
i
x
i , i = 1, 2,···, n ( A = C 14 , B = C 12 ).
研究领域:
物理化学
·
材料科学
·
纳米限域效应
·
热分析
·
软物质物理
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DOI
高影响因子
MATERIALS LETTERS
·
2014
·
IF 2.269
Yaguang Yuan,Yanping Yuan,Nan Zhang,Yanxia Du,Xiaoling Cao
Capric–myristic–palmitic acid ternary eutectic mixture (CA–MA–PA) was prepared as phase change material (PCM). A novel composite PCM of CA–MA–PA/expanded graphite (EG) with an optimum mass ratio (CA–MA–PA:EG=13:1) was prepared by uniformly absorbing CA–MA–PA into the porous network structure of the EG. The melting and freezing temperatures of CA–MA–PA/EG composite PCM were measured by differential scanning calorimeter as 18.61 °C and 16.58 °C, respectively, while the melting and freezing latent heats were 128.2 J/g and 124.5 J/g, respectively. The thermal conductivity of the CA–MA–PA/EG composite PCM was measured as 3.67 W/m K and thus the thermal storage and release rates were significantly increased. The thermal cycling test results showed that CA–MA–PA/EG composite PCM has a good thermal reliability. All the above results show that the CA–MA–PA/EG composite PCM is a potential solution for latent heat storage system.
研究领域:
材料科学
·
能源化学
·
热物理
·
功能材料
·
储能技术
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高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2024
·Vol. 50
·期 3
·e202400232
·
IF 1.7
Bo Hao,Caixian Xu,Geng Chen,Yuangen Lu,Li Zhang
In response to issues such as poor accuracy and unstable delay times encountered in the practical use of tungsten-based delay compositions, an analysis of the combustion performance of tungsten-based delay compositions with the addition of copper oxide was conducted. This study selected five tungsten-based composite delay compositions prepared by blending tungsten-based delay compositions with copper oxide at different content, aiming to investigate the influence of varying copper oxide proportions on the combustion characteristics of tungsten-based delay compositions. Microscopic morphologies and thermal decomposition behaviors of the tungsten/copper oxide delay compositions were analyzed using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), while combustion products were examined by X-ray diffraction (XRD). The results indicate that copper oxide exerts a strong catalytic decomposition effect on tungsten-based delay compositions. Specifically, a low concentration of copper oxide enhances the combustion rate of tungsten-based delay compositions, while an increase in copper oxide content subsequently slows down the combustion rate. Notably, tungsten-based delay compositions with 9% copper oxide content demonstrate high precision, good stability, and a relatively slow combustion rate, offering a wider range of adjustability for controlling the combustion speed of delay compositions and providing a feasible method for managing the delay time range in practical applications.
研究领域:
材料科学
·
火工品技术
·
燃烧学
·
无机化学
·
功能材料
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DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2014
·Vol. 119
·期 1
·205-212
·
IF 2.206
Yang Ting,Chen Liping,Chen Wanghua,Zhou Yishan,Gao Haisu,Zhong Tingting
2-Ethylhexyl nitrate (EHN) is an important material, which is produced by concentrated HNO 3 –H 2 SO 4 nitration process. But EHN is not a stable material, especially mixed with acids. To analyze the stability of EHN with concentrated acid under serious condition, four samples (pure EHN, concentrated sulfuric acid with EHN, concentrated nitric acid with EHN, and mixed acid with EHN) and three acids (sulfuric acid, nitric acid, and mixed acid) were measured by differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC) in this paper. The results indicated that concentrated sulfuric acid, concentrated nitric acid, and mixed acid all could decrease the onset decomposition temperature of EHN, especially concentrated sulfuric acid. DSC results also showed that the heat of EHN decomposition with nitric acid is larger than other samples. Based on ARC data, the kinetic parameters and T
D24 (temperature at which TMR
ad is 24 h) were calculated. The activation energy and T
D24 of the EHN with acids, especially with concentrate sulfuric acid, were much lower than the pure EHN. It can be concluded that acids could decrease the stability of EHN and that is an important reason for frequent accidents.
研究领域:
物理化学
·
安全工程
·
材料化学
·
热分析
·
危险品管理
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2013
·Vol. 51
·期 9
·2016-2023
·
IF 3.543
CaiFei Wang,ChunHua Zhao,JiaQin Sun,SanQing Huang,XiangDong Liu,Takeshi Endo
A fully bio-based benzoxazine, 3-furfuryl-8-methoxy-3,4-dihydro-2H-1,3-benzoxazine (Bzf), has been prepared using guaiacol, furfurylamine, and paraformaldehyde as raw materials. Its chemical structure has been characterized by 1H and 13C NMR, FTIR, and elemental analysis. The polymerization behavior of Bzf in the presence of methyl p-toluenesulfonate (PTSM) has been studied by FTIR and DSC, and the thermal stability of the cured resin has been evaluated by thermogravimetric analysis. It was found that PTSM is a good promoter that serves to avoid thermal decomposition of the bio-based monomer during the curing process at high temperature. In contrast to the situation with neat Bzf, the presence of PTSM (5 mol % for Bzf) significantly improves the polymerization behaviors, including a decrease in the polymerization temperature from 240 to 174 °C, a shortening of the time required to reach the gel point on heating at 200 °C from 47 to 20 min, and an increase in the char yield of the cured resin from 53 to 62%. Moreover, these observed experimental results on the promoting effect of PTSM are interpreted in terms of several possible mechanistic schemes, which involve a catalytic effect on the dissociation of C O bonds in both the coordination ring-opening reaction and the rearrangement from a phenoxy structure to a phenolic structure. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
研究领域:
高分子化学
·
材料科学
·
热分析
·
绿色化学
·
功能高分子
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DOI
高影响因子
THERMOCHIMICA ACTA
·
2016
·
IF 1.938
Lipeng Wang,Fucheng Zhang,Yongping Bai,Liping Ding
The kinetic of non-isothermal crystallization of Poly (ethylene terephthalate-co-sodium-5-sulfo- iso -phthalate) (PETI) was investigated using differential scanning calorimetry (DSC). Various macrokinetic models namely the Avrami, Tobin, Ozawa, and Ziabicki were used to describe the non-isothermal crystallization process of PETI. Both of the Avrami crystallization rate constant and the Tobin crystallization rate constant were observed to increase with increasing cooling rate. The Avrami model is better than the Tobin model to describe the non-isothermal crystallization process of PETI. The Ozawa crystallization rate K O was found to decrease with increasing cooling rate, while Ziabicki’s kinetic crystallizability parameter G Z was found to increase with increasing cooling rate. The effective energy barrier △E for non-isothermal crystallization process of PETI, analyzed based on the differential iso-conversional method of Friedman, was found to be an increasing function of the relative crystallinity.
研究领域:
高分子化学
·
材料科学
·
物理化学
·
热分析
·
聚合物结晶
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DOI
高影响因子
危险品化学品经营许可证（带存储）