重结晶工艺对太安撞击感度的影响

用溶剂-非溶剂法重结晶粗制太安,研究了溶剂-非溶剂体系、重结晶温度、搅拌速度和非溶剂滴加速度4个因素对重结晶太安撞击感度的影响.测定了不同工艺条件下重结晶太安的特性落高,通过金相显微镜和偏光显微镜分析了不同结晶工艺所得太安晶体的形貌及表观缺陷,讨论了重结晶工艺对太安晶体撞击感度的影响.结果表明,以乙酸乙酯为溶剂,三氯甲烷为非溶剂,温度50℃, 非溶剂稀释速度0.05 mL/min,搅拌速度100 r/min条件下制备的重结晶太安的特性落高为14.6 cm,比常用的丙酮-水重结晶太安的撞击感度显著降低.     

太安的降静电表面处理

介绍了用表面活性剂处理太安的方法，对处理后的太安进行了静电性能测试和分析，得出最佳抗静电用表面活性剂的种类及使用浓度。实验结果表明。太安炸药经过表面活性剂处理后，其静电得到大幅度降低，有利于导爆索生产工艺与质量。     

体积排除色谱法测定太安炸药的痕量同系物

本文阐述应用现代的体积排除色谱技术,测定季戊四醇单硝酸酯、季戊四醇三硝酸酯、二季戊四醇六硝酸酯、三季戊四醇八硝跨酯等太安炸药的痕量同系物的定性检测和定量分析方法。     

γ辐照PA1010－Nd2O3体系的研究

本文利用ＷＡＸＤ、ＤＳＣ、ＥＳＲ方法研究了ＰＡ１０１０－Ｎｄ２Ｏ３体系的辐射效应，主要讨论了结晶－非晶的界面（结晶表面）对辐射效应的影响。结论如下：结晶表面影响ＰＡ１０１０的辐射交联，结晶的破坏剂量因结晶表面积增大而提高。具有相同浓度的成核剂，但结晶度不同的试样，它们的结晶表面积取决于结晶度，它们的辐射效应由于微晶尺寸与结晶表面积的差异而不同。结晶度越大，微晶尺寸越大，结晶越完善，结晶的表面积越大，结晶结构不易受到γ辐照的破坏。结晶表面对结晶结构起着保护作用，进一步证明了结晶表面是结晶破坏的始点     

γ辐照PA1010—Nd2O3体系的研究

本文利用ＷＡＸＤ，ＤＳＣ，ＥＳＲ方法研究了ＰＡ１０１０－Ｎｄ２Ｏ３体系的辐射效应主要讨论了结晶－非晶的界面（结晶表面）对辐射效应的影响，结论如下：结晶表面影响ＰＡ１０１０的辐射交联，结晶的破坏剂量因结晶表面积增大而提高，具有相同浓度的成核剂，但结晶度不同的试样，它们的结晶表面积取决于结晶度，它们的辐射效应由于微晶尺寸与结晶表面积差异而不同，结晶度越大，微晶尺寸越大，结晶越完善，结晶的表面积越大，结     

PET五苯甲酸钠共混物等温结晶行为的研究

运用结晶速度仪对ＰＥＴ与苯甲酸钠共混物的等温结晶行为进行了研究。结果表明，随着苯甲酸钠添加量的增加。ＰＥＴ共混物的结晶诱导缩短，总体结晶速度加快，结晶活化能减小，证明苯甲酸钠是ＰＥＴ良好的结晶成核剂。     

PET与苯甲酸钠共混物等温结晶行为的研究

运用结晶速度仪对ＰＥＴ与苯甲酸钠共混物的等温结晶行为进行了研究。结果表明，随着苯甲酸钠添加量的增加，ＰＥＴ共混物的结晶诱导期缩短，总体结晶速度加快，结晶活化能减小；证明苯甲酸钠是ＰＥＴ良好的结晶成核剂     

溶析结晶在医药领域的研究进展

结晶作为一种传统的分离和提纯工艺，广泛运用于医药、化工、材料等领域。随着对结晶工艺的深入研究和对晶体产品质量越来越高的要求，结晶不再仅仅用于物质的分离和提纯，更重要的是根据产品功能的需要，制备特定结构的晶体。作为结晶的重要组成部分，溶析结晶因其操作简单、能耗相对较低、适用于热敏性物质等优势受到了广泛的关注。本文从溶析结晶相较于其他溶液结晶的不同点出发，重点介绍了溶析结晶热力学、溶析结晶动力学和工艺过程的研究，以及与溶析结晶相关的超临界流体技术和球形结晶技术。溶析结晶热力学关注了溶解度的测定方法和如何通过相图来确定合适的操作条件；溶析结晶动力学，详细描述了间歇、连续溶析结晶动力学模型的建立；工艺过程的研究，包括溶析剂与含有待结晶物质混合、结晶过程的控制和优化。同时本文对溶析结晶目前存在的问题进行了总结，并对未来的发展作了展望。     

磁场影响溶液结晶过程研究进展

论述了磁场对溶液结晶过程影响的研究进展情况，指出磁场不仅可以化溶液结晶过程，刺激结晶成核，提高结晶生长速率，控制晶体粒径的分布，也可抑制溶液的结晶，降低结晶生长速率。针对不同的工程目的，选择合理的磁处理参数显得尤为重要。并提出磁场技术目前存在的问题和展望。     

线形聚丙烯／长链支化聚丙烯共混物的结晶行为研究

通过DSC、XRD和偏光显微镜研究了线形聚丙烯／长链支化聚丙烯共混物的结晶行为、结晶结构和结晶形态。研究结果表明：长链支化聚丙烯的结晶温度比线形聚丙烯提高10℃左右；共混物的结晶行为与长链支化聚丙烯类似，所形成的球晶多而小；由于结晶温度提前，长链支化聚丙烯的作用类似于结晶成核剂，率先形成的晶核具有物理交联点的作用，有效地提高了共混物的熔体强度。对于配比为80／20的线形聚丙烯／长链支化聚丙烯共混物，由于长支链的存在，降温速率越慢，结晶温度越高。结晶过程中并未发生结晶结构和结晶形态的改变。     

Effect of Porphyrin Doping on Thermodynamic Parameters of Pentaerythritol Tetranitrate (PETN) Single Crystals

The search for ways to enhance the stability of PETN against sublimation and coarsening, as well as controlling its thermodynamic properties, is of great interest. In this article, the possibility to use biological molecules to enhance the stability of the important explosive PETN was investigated using thermogravemitric analysis (TGA). Doping PETN with free and metallated porphyrins result in the formation of more stable crystals. Hydrogen bonding between free porphyrins and metal coordination of metallated porphyrins is most likely to play an important role in the crystallization process of PETN. The results indicate the ability of porphyrins molecules to affect/control the thermodynamic properties of PETN inducing a desired higher stability against sublimation. This study opens the door to investigate the use of polymers to enhance the stability of energetic materials.     

Synthesis, crystallization and tensile properties of poly(ethylene terephthalate-co-2,6-naphthalate)s with low naphthalate units content

A series of poly(ethylene terephthalate-co-naphthalate)s (PETN copolymers) with low naphthalate units content was synthesized. A melting point depression was observed, while the glass transition temperatures were slightly higher than that of Polyethylene terephthalate (PET). Crystallization rates of the copolymers decreased with increasing comonomer content. WAXD patterns showed that only PET crystals were formed. Co-crystallization behaviour was evaluated on the basis of the Wendling–Suter model. The tensile properties of the copolymers PETN 97/3 and PETN 94/6, Young's modulus yield stress and elongation at break was significantly improved compared to PET. WAXD showed that some crystalline precursor was generated during drawing of the specimens. DSC traces of the drawn specimens showed enhanced crystallization rates compared to that of the original amorphous specimens.     

Stability Studies on Pentaerythritol Tetranitrate

Tyhe influences of acidity and dipentaerythritol hexanitrate (DiPEHN) on the thermal sensitivity of pentaerythritol tetranitrate (PETN) was studied using differential scanning calorimetry (DSC). Decomposition kinetics of PETN with or without DiPEHN, acidic PETN and DiPEHN were also studied by SC to evaluate Arrhenius parameters. The presence of sulphuric acid impurity decreased the thermal stability as well as the activation energy, whereas the nitric acid influence was negligible. Thermal stability of PETN was not affected by the presence of DiPEHN. DiPEHN showed better thermal stability and higher decomposition energy compared to PETN.     

Sublimation Properties of Pentaerythritol Tetranitrate Single Crystals Doped with Its Homologs

Pentaerythritol tetranitrate (PETN) is a secondary explosive used extensively in military and commercial applications. Coarsening of PETN during long‐term storage changes the physical properties such as surface area and particle morphology which are important factors in initiation and performance. Doping of impurities was proposed to slow the coarsening process since impurities were shown to modify both the kinetic and thermodynamic properties. In this paper, we discuss how doping of PETN with its homologs of dipentaerythritol hexanitrate (diPEHN) and tripentaerytritol octanitrate (triPEON) affect kinetic and thermodynamic parameters. Pure and homolog doped PETN single crystals were prepared by solvent evaporation in acetone at room temperature. Doping concentrations for this study were 1000 ppm, 5000 ppm, and 10000 ppm. Activation energy and vapor pressure of pure and doped PETN single crystals were obtained from thermogravimetric analysis data.     

Effects of epoxy treatment of organoclay on structure, thermo-mechanical and transport properties of poly(ethylene terephthalate-co-ethylene naphthalate)/organoclay nanocomposites

Poly(ethylene terephthalate-co-ethylene naphthalate) (PETN) nanocomposites containing two different organoclays, Cloisite 20A and 30B, were prepared by melt intercalation using an extruder. The organoclays was treated with epoxy monomer to further improve the polar interactions with PETN matrix. The morphological, thermal-mechanical, mechanical and gas barrier characteristics of the nanocomposites were evaluated using several characterization tools. It is found that the Cloisite 30B had better interactions with PETN and was more uniformly dispersed within PETN than Cloisite 20A. Epoxy treatment of Cloisite 30B organoclay resulted in improvements in d-spacing between silicate layers, thermo-mechanical and tensile properties, as well as thermal stability, processing and gas barrier characteristics of the PETN/30B nanocomposites. These results suggest that the epoxy acted as the compatibilizer as well as the chain extender, improving the chemical interactions between PETN and organoclay, while discouraging the macromolecular mobility of polymer chains in the vicinity clay particles. The implications and the mechanisms behind these observations are discussed.     

Laser initiation of low-density mixtures of PETN with metal additives

This paper presents data on laser initiation of low-density mixtures of PETN with metal additives with varying dispersity of PETN and particle size of the additive. A laser with a wavelength of 1.06 μm and a pulse length of 40 and 30 ns was used. Curves of the threshold initiation parameters on the additive content are shown to have minima. For coarse additives, no significant dependence of the initiation threshold of the mixtures on the nature of the metal at its optimal content (except for aluminum) was observed. For PETN mixtures with an optimal amount of fine aluminum, a significantly greater (a factor of 6.2) decrease in the threshold initiation parameters compared to direct initiation of PETN was found. It is shown that the initiation thresholds of the mixtures do not depend on the dispersity of PETN with the optimal additive content. Increasing the dispersity of PETN extends the dependences of the threshold parameters on the additive content while the optimal additive content is shifted to higher values. The initiation thresholds are found to strongly depend on the density of the mixture charge. The key points of the mechanism of laser initiation of PETN mixtures with additives are formulated.     

PET-PEN共聚酯的合成研究

以2,6-萘二甲酸(NDA)、对苯二甲酸或2,6-萘二甲酸二甲酯(NDC)、对苯二甲酸二甲酯与乙二醇为原料,在2 L聚合反应装置上,采用直接酯化法或酯交换法合成聚对苯二甲酸乙二酯(PET)-聚2,6-萘二甲酸乙二酯(PEN)共聚酯(PETN),探讨了PETN的合成反应条件。结果表明:直接酯化法较酯交换法更加可行易控;直接酯化法反应条件:酸/醇摩尔比为1:(1.3～1.5),NDA摩尔分数(相对于酸的总量)为28%,酯化阶段无需催化剂,酯化反应温度220～250℃,缩聚反应温度280～295℃,合成的PETN特性黏数达0.65～0.85 dL/g;钛系催化剂的催化活性优于锑系催化剂,且添加比例小,添加量为8～50μg/g时,即可得到高特性黏数的PETN。     

Thermal Decomposition of Pentaerythritol Tetranitrate

A chemical kinetic model for the thermal decomposition of the solid high explosive pentaerythritol tetranitrate (PETN) is developed for prediction of times to thermal explosion using the Chemical TOPAZ heat transfer computer code. The model is based on times to thermal explosion measured in a new One Dimensional Time to Explosion (ODTX) apparatus. ODTX experiments are reported for pure PETN and for Semtex 1A. The pure PETN results are accurately modeled using a four reaction decomposition process in which an autocatalytic process produces intermediate reaction product gases, which subsequently react in a second order gas phase process to produce the final reaction products. Semtex 1A exhibits longer times to explosion than PETN at low temperatures, indicating that its endothermic binder decomposition absorbs heat produced by PETN decomposition. This binder reaction is modeled as a first order endothermic process. Three experiments on 5.08 cm diameter unconfined cylinders of PETN ramp heated to explosion at different rates are reported. The PETN model accurately predicts the thermocouple records and explosion times for these unconfined experiments in which only intermediate gaseous products can form.