Effect of Different Polymeric Matrices on Some Properties of Plastic Bonded Explosives

Matrices based on polyisobutylene (PIB), polymethyl‐methacrylate (PA), Viton A 200, Dyneon FT 2481 (Fluorel), and polydimethyl‐siloxane binders were studied as desensitizers. A series of plastic explosives (PBXs) were prepared, based on four different nitramines, namely RDX (1,3,5‐trinitro‐1,3,5‐triazinane), β‐HMX (β‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane), BCHMX (cis‐1,3,4,6‐tetranitro‐octahydroimidazo‐[4,5‐d]imidazole) and ε‐HNIW (ε‐2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane, ε‐CL‐20), bonded by the matrices mentioned. For comparison, pentaerythritol tetranitrate and certain commercial explosives based on it, Semtex 1A, Semtex 10 and Sprängdeg m/46, were used. Detonation velocities, sensitivities to impact and friction, and peak temperatures of thermal decomposition by differential thermal analysis technique (DTA) for all the explosives studied were determined. Heat of detonation was calculated by means of a thermodynamic calculation program (EXPLO 5 code). Fluoroelastomers have a neutral to positive effect on the thermal stability of nitramines and they have a significant effect on decreasing the friction sensitivity. However, their anti‐impact efficiency is the lowest in this study although they have a positive effect on performance of the corresponding PBXs. PA and PIB matrices markedly decrease thermal stability of nitramines, the anti‐impact influences of PIB‐binders are better than those of PA‐binders, while PA‐binders have a higher anti‐friction effect and slightly less negative influence on the performance of the PBXs in comparison with PIB mixtures. The polydimethyl‐siloxane matrix has a neutral effect on thermal stability of the nitramines studied, it has an influence on the volume thermochemistry of detonation comparable with that of fluoroelastomers although it does not provide comparable performance, and its corresponding PBXs have optimum sensitivity parameters.     

Polymeric Materials with Magnetic Properties

The paper deals with the study of the magnetic properties of some mechanochemically synthesized polychelates. Some spectral analysis methods such as ESR spectroscopy, atomic absorption spectroscopy, and especially Mössbauer spectroscopy are used for this purpose. The presence of metallic atoms (especially Fe) is responsible for the magnetic properties of these mechanochemically synthesized macromolecular compounds.     

Computer Prediction and Analysis of Functional Properties of Synthetic Textile Materials

Fibre Chemistry - Methods of mathematical modeling, computer prediction, and systems analysis of functional properties of synthetic textile materials are reviewed. The developed models and methods...     

自组装功能高分子材料表面的相互作用

分析了氢键作用、范德华能、静电作用能、交换排斥能等高分子材料表面的相互作用及其影响因素,综述了自组装纳米材料、自组装嵌段共聚物和自组装生物大分子材料等功能高分子材料表面的相互作用,讨论了表面的相互作用类型和强弱对其自组装机理、结构、性能的影响,展望了新型功能高分子材料的开发和发展方向。     

有机/高分子光诱导电荷转移材料研究

光诱导电子转移是光电转换体系中发生的一个简单而重要的过程,即:在受到光激发时,一个电子从电子给体(D)转移到电子受体(A)并形成给体自由基阳离子(D·+)和受体自由基阴离子(A·-)的过程.与之相伴的另一个过程是后电子转移过程,即电子重新回到体系的最初状态的过程.为了使放热式电子转移过程顺利进行,最重要的决定因素在于电...     

功能树脂分子结构对橡胶阻尼材料性能的影响

研究不同分子结构的功能树脂对以天然橡胶及其与丁苯橡胶的并用体系为基体的阻尼橡胶材料性能的影响,探索提高阻尼橡胶材料的阻尼性能的方法。通过功能树脂调整阻尼橡胶材料的损耗因子（tanδ）曲线是在保持其高弹性的同时提高其阻尼特性的一种有效方法。不同分子结构的树脂与橡胶相容性的差异对于调整不同温度范围内使用的橡胶阻尼材料的tanδ曲线具有重要意义。试验结果表明,通过树脂分子结构的调控,可以实现特定温度范围内橡胶阻尼材料的tanδ的增大,从而提升橡胶阻尼制品的阻尼性能。     

Dynamic–Mechanical Properties of Bioartificial Polymeric Materials

Bioartificial polymeric materials represent a new class of polymeric materials based on blends of synthetic and natural polymers, designed with the purpose of producing new materials with enhanced properties with respect to the single components. The mechanical properties of bioartificial materials prepared using poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) as synthetic components, and collagen (SC), gelatin, starch, hyaluronic acid (HA) and dextran as biological components, were investigated by dynamic mechanical thermal analysis. The materials were prepared in the form of films or hydrogels and treated by glutaraldehyde (GTA) vapour or thermal dehydration in order to reduce their solubility in water. The results indicate that SC/PVA, gelatin/PVA and starch/PVA films behave as biphasic systems, showing good mechanical properties over a wide range of temperature. It was observed that the GTA procedure affects only the biological component of the SC/PVA and gelatin/PVA blends, whilst the thermal treatment influences mainly the synthetic polymer. In the case of HA/PVA hydrogels, a modulus variation was found with the HA content related to the organization degree and perfection of the PVA network structure. It seems evident that, in the experimental conditions used, dextran/PAA mixtures behave as miscible blends showing a glass transition intermediate between those of the pure components. With both untreated and GTA-treated gelatin/PMAA blends, it was not possible to evaluate the miscibility of the systems; it could only be affirmed that these materials show good mechanical properties over a wide range of temperature. © 1997 SCI.     

A Review on Preparation,Properties and Applications of Polymeric Nanoparticle-Based Materials

Polymeric nanoparticles (PNPs)-based materials have gained much deliberation due to advancement in polymer science and technology. PNPs are playing an eccentric role in broad spectrum of applications. The importance of these materials lies in idiosyncratic features associated with PNPs. Due to the impact of the materials on nanotechnology; a comprehensive review has been presented here. We covered not only different techniques for the fabrication of PNPs, but also highlighted the properties and parameters involved and enhanced in PNP-based materials. Moreover the worth of PNP-based materials in applications regarding nanocomposites, drug delivery for cancer treatment, and photovoltaic relevance has been discussed.     

Preliminary Studies on the Properties of Novel Polymeric Composite Materials Based on Polysuccinates

This study aimed to prepare novel biodegradable polymeric composites based on poly(3-allyloxy-1,2-propylene) succinate (PSAGE). These composite materials are composed of poly(ester-anhydride) (PEA) microspheres embedded in polyester matrix prepared by crosslinking PSAGE with oligo(1,2-propylene maleate) and methacrylic monomers. Methyl methacrylate and one of hydrophilic oligo(ethylene glycol) dimethacrytes with different length of oligooxyethylene chains were used as polymerizable solvents. Incorporation of microspheres that degrade faster than crosslinked polyester matrices enables formation of porous structure. The obtained materials are liquid before curing and harden in several minutes with moderate exothermic effect. The effect of the composition of polyester matrices and kind of PEA microspheres used on selected properties, such as water sorption, mechanical strength, porosity, and hydrolytic degradation behavior, was investigated. The morphology of the cured composite materials subjected to hydrolytic degradation was evaluated by SEM.     

基于粘着摩擦理论的塑料微观摩擦特性研究

利用纳米压痕仪测试ABS塑料的弹性模量,为了研究塑料材料微观摩擦性能,设计了一套测试制样方案,采用纳米划痕技术实测了ABS塑料的微观摩擦性能,并结合粘着摩擦理论对塑料摩擦特性进行了分析。纳米压痕结果,ABS塑料弹性模量均值约为4.20 GPa;纳米划痕结果,弹性接触和塑性接触时摩擦因数分别约为0.1和0.25;对比理论分析和实验结果发现,粘着摩擦理论用于解释塑料材料微观摩擦行为是可行的。     

Improvement of Mechanical Properties of Plastic Bonded Explosive Using Neutral Polymeric Bonding Agent

The technical objective of this investigation is to examine the processability and achievement of high tensile strength of AFX-231 through the use of NPBA as a replacement for nitrocellulose as a bonding agent. This study is centered on the formulation in which HMX solid particles are dispersed in the binder matrix containing highly polar plasticizer such as DEGDN, BTTN and PGA. When nitrocellulose of AFX-231 was replaced by NPBA as a bonding agent, a significant increase in the initial modulus and the stress were observed, while impact and friction sensitivities showed no differences. This observation indicates the hard shell formation around the particles. Among the modified formulations, Mod-24 showed less impact and friction sensitivities and higher initial modulus and maximum stress.     

高分子材料的循环利用

概述了近年来与环境治理的有关的一个重要主题－高分子材料循环利用的发展状况的新型循环技术,同时对高分子材料循环存在的问题,将来的发展趋势和前景作了讨论。     

橡实基复合高分子材料的制备与性能研究（摘要）

先对橡实淀粉、橡实果仁和橡实果壳3种原料进行了理化分析,对研究中所采用3种原料的各个组分的含量具有初步的认知,以期为开发橡实资源的不同用途提供依据。研究发现橡实果仁中含有69.40%的淀粉,其中支链淀粉含量高达59.01%,单宁含量为8.34%;橡实淀粉原料的淀粉含量高达87.21%,其中支链淀粉含量高达68.56%,...     

高分子材料银纹研究

结合国内外研究状况,对银纹结构、引发、生长以及断裂进行了全面的介绍和分析,总结了近年来对银纹认识的发展,并对今后研究的重点和趋势进行了展望。     

超分散剂对塑木复合材料性能的影响

以松香、二乙撑三胺和12-羟基硬脂酸为原料,合成了松香超分散剂(RDH)。用RDH对高密度聚乙烯塑木复合材料进行改性,研究了RDH对塑木复合材料力学性能、热性能等的影响,并用扫描电镜(SEM)观察复合材料的冲击断面形貌。结果表明:经RDH改性后,塑木复合材料的冲击强度和弯曲强度分别提高了35.2%和21.5%。RDH的加入改善了复合材料的热稳定性,储能模量提高,损耗因子降低。     

木粉预处理对PP木塑复合料性能影响

采用熔融共混法制备了聚丙烯(PP)木塑复合材料(WPC),研究了木粉含量及预处理方式对WPC力学性能、吸水性能的影响.结果表明:随着木粉含量的增大,WPC的弯曲强度和弯曲模量明显上升,拉伸强度有所降低,而冲击强度基本保持不变.木粉经过化学预处理对WPC力学性能的改善比物理预处理要好.从吸水率来看,随着木粉含量的增大,WPC吸水率保持在0.22％以下,远低于纯木材.     

生物降解高分子材料的研究进展

简要介绍了生物降解高分子材料的定义、分类和降解机理,较为全面地阐述了当前生物降解高分子材料的应用领域,并对其发展前景作出展望。