喷气燃料热氧化机理及氧化稳定添加剂的研究进展

对喷气燃料热氧化沉积形成机理和为提高燃料氧化稳定性而加入的添加剂如硅烷基化试剂、氧清除剂、抗氧剂、金属钝化剂和清净分散剂的发展状况进行介绍,并指出今后燃料添加剂的发展方向。     

CA聚合物的热稳定性

研究不同温度、不同抗氧剂对CA聚合物体系热稳定性与力学性能的影响,比较抗氧剂215和抗氧剂1076体系的抗氧化效果。结果表明:在相同温度下,抗氧剂215的热稳定性和力学性能优于抗氧剂1076。     

氧氟沙星的热稳定性及其热分解动力学

测定了在氮气气氛中第三代氟喹诺酮类药物氧氟沙星(OFLX)的热稳定性。用差示扫描量热法(DSC)、热重法(TG)和微分热重法(DTG),研究了药物氧氟沙星的热分解动力学。计算了动力学参数E、n、A,并结合量子有机化学计算的键长、原子静电荷参数研究了热分解机理,推断了热分解机理及药品贮存期。用热分析研究固体药物的热分解过程方法简便,结果可行。     

裂解气相色谱-质谱法研究芳香族聚酯类纤维热分解

采用裂解气相色谱质谱法研究了600℃时聚对苯二甲酸丁二酯纤维(PBT)、聚对苯二甲酸丙二酯纤维(PTT)和聚对苯二甲酸乙二酯纤维(PET)的热裂解反应,分别鉴别到22种、25种和25种主要裂解产物。PBT的特征性裂解产物是苯甲酸丁烯酯、苯甲酸丁酯、1,4-苯二甲酸-3-丁烯酯、1,4-苯二甲酸-双-3-丁烯酯和二苯甲酸-1,4-丁二醇酯;PTT的特征性裂解产物为苯甲酸丙烯酯、苯甲酸丙酯、对苯二甲酸单丙烯酯、1,4-苯二甲酸-双-2-丙烯基酯、二苯甲酸-1,3-丙二醇酯;PET的特征性裂解产物为苯甲酸乙烯酯、苯甲酸乙酯、苯二甲酸双乙烯酯、二苯甲酸-1,2-乙二醇酯。     

新型多叠氮磷酸酯的热安定性及其热分解机理

用DSC法测定了两种新型链状多叠氮磷酸酯——三(β-叠氮乙基)磷酸酯(TAEP)与2,2-二(氯甲基)-1,3-亚丙基四(β-叠氮乙基)双磷酸酯(MPAEDP)及两种新型双环叠氮磷酸酯——1-氧代-4-(β-叠氮乙氧羰基)(或(β,β′-二叠氮异丙氧羰基)-2,6,7-三氧杂-1-磷杂双环[2．2．2]辛烷(AEPEPA及AIPEPA)的热安定性,并求得了它们的热分解动力学参数(Ea、Aa及ka),讨论了可能热分解机理。     

裂解气相色谱法研究聚对苯二甲酰对苯二胺纤维热分解

采用裂解气相色谱质谱法研究了在400￣700℃之间聚对苯二甲酰对苯二胺纤维(PPTA)的裂解产物组成。400℃时裂解,仅检测到8种裂解产物。随裂解温度上升,裂解产物急剧增加。在700℃时,检测到45种裂解产物,主要特征裂解产物为苯、氰苯、苯胺、苯甲酸、1,4-对苯二胺、苯甲酸N2-苯肼等。聚对苯二甲酰对苯二胺裂解过程中,发生链剪切作用,由聚合物链断裂成单体,经重排、环化、次级反应等形成了各种裂解产物。作出了PPTA裂解过程示意图。     

添加剂对橡胶籽油生物柴油氧化稳定性的改进

测定了橡胶籽油的物化性能及组成. 加入6种抗氧化剂,采用Rancimat法研究了其添加量及复配、温度、0#柴油添加量、金属铜、铁等对橡胶籽油生物柴油氧化稳定性能的影响. 结果表明,橡胶籽油所制生物柴油不饱和脂肪酸含量达82.1%,诱导期为0.81 h,达不到国家标准(6 h). 6种抗氧化剂在添加量为4000′10-6(w)时对橡胶籽油生物柴油的氧化稳定性能均有提升,其中TBHQ效果最好,使其氧化稳定性诱导期达13.09 h,6种抗氧化剂的抗氧化效果为TBHQ>BHT>D-TBHQ>OG>PG>BHA. PG与其他抗氧化剂复配后效果较好,而TBHQ与其他抗氧化剂复配后效果降低. 温度和0#轻柴油添加量对橡胶籽油生物柴油的氧化稳定性能影响很大,随温度升高,诱导期明显缩短,而随0#柴油添加量增大,诱导期增加,添加量较大时诱导期增幅很大. 铁、铜对其氧化稳定性能也有一定影响.     

Thermal Decomposition of Energetic Materials 83. Comparison of the Pyrolysis of Energetic Materials in Air versus Argon

T‐Jump/FTIR spectroscopy was employed to flash pyrolyze a series of energetic compounds in an air atmosphere for comparison with an argon atmosphere. The O‐NO₂ compounds (NG, NC, and PETN), N‐NO₂ compounds (RDX and HMX), and C‐NO₂ compounds (DNT, TNT, and NTO) were studied. The effect of the surrounding atmosphere on the pyrolysis gases roughly correlates with the trend in the vapor pressure of the parent energetic material (i. e. DNT>NG>TNT>NTO>PETN≈RDX>NC≈HMX). For high vapor pressure compounds, the gaseous phase reactions dominate and the dependence on the surrounding atmosphere is strong. For low vapor pressure compounds, the condensed phase decomposition dominates and the dependence on the surrounding atmosphere is weak. That is, the extent of condensed phase vs. gas phase decomposition is the major factor in the effect of the surrounding atmosphere on the decomposition gases. The main reactions in the air are CO with O₂ which is fast, and NO with O₂, which is slow. However, these pyrolysis products for the nitrate esters, the nitramines, and the C‐NO₂ compounds behave differently suggesting that a common process, such as surface catalysis, is not responsible for the behavior seen. There is little effect of the relative humidity (0–60% range) except in the case of HMX.     

纳米SiO2填充PE-LLD复合材料的热稳定性和热氧稳定性研究

采用TG法研究了纳米SiO2含量、界面特性对纳米SiO2填充PE—LLD复合材料热降解和热氧降解性能的影响，并用Dole-Ozawa方法研究了体系的热降解动力学。结果表明：复合材料热降解和热氧降解温度均随纳米SiO2含量的增加而提高，后者提高更为显著。硅烷偶联剂表面改性纳米SiO2填充PE—LLD体系中加入大分子相容剂PE-LLD-g-MAH后，其热稳定性和热氧稳定性均优于未加PE-LLD-g-MAH体系。此外，纳米SiO2含量对复合材料热降解表观活化能Ea影响较大，填充体系的平均热降解表观活化能比基体明显提高，且随着SiO2含量增加而增大；界面特性对Ea的影响较小。     

助剂对POM的长期热氧稳定化作用研究

针对聚甲醛（POM）热稳定性较差的问题,研究了抗氧剂、吸醛吸酸剂和成核剂对其长期热氧稳定化的影响。结果表明,经120℃／1000h的热氧老化后,吸醛剂K-3对POM的断裂伸长率保持率的改善最为明显,达99．5％;成核剂则在保持POM力学性能的基础上,有效降低了热氧老化后的b值,显示了优异的长期热氧稳定化作用。     

1-丁基-3-甲基咪唑二氰胺盐离子液体的热稳定性和热分解动力学(英文)

Thermal stability and thermal decomposition kinetics of 1-butyl-3-methylimidazolium dicyanamide ([bmin+][N(CN) ]2-) were investigated using both isothermal and non-isothermal thermogravimetric analyses (TGA) under high pure nitrogen as carrier gas. The long-term thermogravimetric studies revealed that the highest temperature used should be 110 °C, at which [bmin+][N(CN)2-] lost less than 10% by mass in 10 hours. The non-isothermal activation energy values determined using Friedman and ASTM methods were (150±13) and (147±2) kJ·mol –1 , respectively. Multivariate non-linear-regression methods showed that expanded Fn and CnB models were the best fit models with highest correlation coefficient of 0.9994, and the apparent activation energies were consistent with iso-conversional methods.     

热稳定性添加剂对喷气燃料电导率的影响

针对热稳定性添加剂对喷气燃料电导率的明显改变作用,介绍了几种热稳定性添加剂、抗静电添加剂和其他添加剂在喷气燃料中的抗静电效果,重点考察了不同添加剂复配后对喷气燃料电导率的影响作用。讨论了热稳定性添加剂与抗静电添加剂和其他添加剂间相互作用对碳氢液体电导率的影响机理。     

Comparison of a New Estolide Oxidative Stability Package

The rotating pressurized vessel oxidation test (RPVOT) was used in the analysis and determination of a new oxidative stability package (OSP) for a series of estolide based materials. Three antioxidants (BHT, two different alkylated diphenyl amines) were used in either 0.5 or 1.0 wt/wt%, in different ratios, and in conjunction with one another (hindered phenol/alkylated diphenyl amines or hindered phenol/mixed alkylated diphenyl amines). The estolide-based samples analyzed for their resistance to oxidation were two pure (distilled) estolides (oleic estolide 2-EH esters and coco-oleic estolide 2-EH esters), an estolide mixture that was analyzed straight from the reaction (coco-oleic estolide 2-EH esters with coco 2-EH esters) and finally the ester fraction from the estolide mixture (coco 2-EH esters). The coco estolide mixture and coco 2-EH esters had the best overall RPVOT times with 1.0% of the alkylated diphenyl amine, coco estolide mixture, 326 min, and coco 2-EH esters, 310 min. Coco estolides were expected to have an advantage over the simple oleic estolides due to the increase in saturation in the estolide. Unexpectedly, the two distilled estolides (oleic and coco) had very similar RPVOT max times with all the antioxidants, and were much higher than the other oxidative packages tested to date. In general, the alkylated diphenyl amine outperformed mixed alkylated diphenyl amines in the majority of the individual samples tested specially the coco 2-EH esters and distilled coco-oleic estolide 2-EH esters material at 1% OSP. Overall, a series of new antioxidants were tested and compared to other commercial products. A variety of physical properties of the four estolide based material were collected and compared to commercially acceptable material. Coco-oleic estolide 2-EH esters were formulated to have excellent pour points (−36 °C), were both oxidatively and hydrolytically stable (RPVOT, 310 min), with expected good biodegradability which should help commercialization. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Thermal Decomposition of Polymer Mixtures Containing Poly(vinyl chloride)

Thermal decomposition of a series of 1 : 1 mixtures of typical polymer waste materials [polyethylene (PE), poly(propylene) (PP), polystyrene (PS), polyacrylonitrile (PAN), polyisoprene, poly(methyl methacrylate) (PMMA), polyamide‐6 (PA‐6), polyamide‐12 (PA‐12), polyamide‐6,6 (PA‐6,6), and poly(1,4‐phenylene terephthalamide) (Kevlar)] with poly(vinyl chloride) (PVC) was examined using thermal analysis and analytical pyrolysis techniques. It was found that the presence of polyamides and PAN promotes the dehydrochlorination of PVC, but PVC has no effect on the main decomposition temperature of polyamides. The hydrogen chloride evolution from PVC is not altered when other vinyl polymers or polyolefins are present. The thermal degradation of PAN is retarded significantly, whereas that of the other vinyl polymers is shifted to a slightly higher temperature in the presence of PVC. Among the pyrolysis products of PAN‐PVC mixture methyl chloride was found in comparable amount to the other gaseous products at 500°C pyrolysis temperature.     

Investigation on Decomposition Kinetic and Thermal Stability of Metallocene Catalysts

Data on thermal stability of metallocene catalysts such as bis(n-butyl cyclopentadienyl) zirconium dichloride and bis(t-butyl cyclopentadienyl) zirconium dichloride is required because of their application in high temperature polymerization process. In the present study, the thermal stability of the bis(n-butyl cyclopentadienyl) zirconium dichloride and bis(t-butyl cyclopentadienyl) zirconium dichloride was determined by differential scanning calorimetry (DSC) and simultaneous thermogravimetry-differential thermal analysis (TG-DTA) techniques. The results of TG analysis revealed that the main thermal degradation for the bis(n-butyl cyclopentadienyl) zirconium dichloride and bis(t-butyl cyclopentadienyl) zirconium dichloride occurs in the temperature ranges of 194–360 °C and 195–350 °C, respectively. On the other hand, TG-DTA analysis indicated that bis(n-butyl cyclopentadienyl) zirconium dichloride melts (about 98.7 °C) before it decomposes. However, the thermal decomposition of the bis(t-butyl cyclopentadienyl) zirconium dichloride was started simultaneously with its melting. Also, the kinetic parameters such as activation energy and frequency factor for both compounds were obtained from the DSC data by non-isothermal methods proposed by Kissinger and Ozawa. Based on the values of activation energy obtained by Kissinger and Ozawa methods, the following order for the thermal stability was noticed: bis(t-butyl cyclopentadienyl) zirconium dichloride >bis(n-butyl cyclopentadienyl) zirconium dichloride. Finally, the values of ΔS^#, ΔH^# and ΔG^# of their decomposition reaction were calculated.     

添加剂对硝酸铵热稳定性及爆炸性的影响

对硝酸铵及其混合物的热分解机理进行了总结.就添加物对硝酸铵热稳定性及爆炸性的影响研究的最新进展情况进行了系统介绍.     

聚合物/粘土纳米复合材料的热稳定性能和阻燃性能

综述了国内外近年来对蒙脱土的有机改性、聚合物/粘土纳米复合材料的制备以及材料的热性能和阻燃性能等方面应用研究的现状。     

Enhanced Thermal Stability of Inverted Polymer Solar Cells with Pentacene

In this study, we focused on the thermal stability of organic solar cells based on poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C₆₁-butyric acid methyl ester (PCBM), fabricated by blends of P3HT : PCBM : pentacene. Enhanced thermal stability of organic solar cells was achieved by introducing pentacene (Pc) into blends of P3HT : PCBM in organic solar cells with the structure indium tin oxide/ZnO/P3HT : PCBM : Pc/poly(3,4-ethylenedioxythiophene) : polystyrene sulfonate/Ag (ITO/ZnO/P3HT : PCBM : Pc/PEDOT : PSS/Ag). The donor-acceptor interfaces of devices with Pc were more stable than those without Pc in the active layer. During the thermal annealing process, the Pc in the P3HT : PCBM blends suppressed the crystallization of P3HT and PCBM, which was confirmed by optical microscopic images and UV-visible absorption spectra. The power conversion efficiency (PCE) of the device with Pc was reduced to no less than 70 % of its original efficiency after keeping it at 120 °C for 24 hours, while that of the non-Pc device was reduced to 13 % of its original efficiency after 24 hours at the same temperature. Based on these results, we propose a new Pc-blended organic solar cell that has advantages in the thermal annealing process.     

CL-20热分解的动态真空安定性试验方法

采用动态真空安定性试验(DVST)法,在真空密闭条件下对CL-20的热分解过程进行了研究.结果表明,在90～140℃,CL-20非等温阶段的热分解反应机理函数为Avrami-Erofeev方程,表观活化能Ea为165.3kJ·mol-1,指前因子In(A/s-1)为40.20.等温阶段热分解反应的机理函数随试验温度的不...     

5种化工添加剂对石化用环丁砜热稳定性影响

以SO2的释放量作为环丁砜热稳定性的评价指标,考察了5种化工添加剂对环丁砜热稳定性的影响.结果表明:在环丁砜用量100 g、氮气流量80 mL·min-1、反应温度230℃、反应时间6 h的条件下进行实验,当HW-M-1投加量达0.10 g时,SO2产生量为18.12 mg;当HW-D-01投加量达0.08 g时,SO...