New antifriction materials of the Fluvis group based on modified carbon fibers

Physicomechanical properties are given for antifriction materials based on fluoroplast-4: Flubon 20, Fluvis 20, Vako-fluvis, and Superfluvis.     

Highly permeable polymer materials based on silicon-substituted norbornenes

An approach to the manufacture of highly permeable polymers based on the synthesis and polymerization of norbornenes, norbornadienes, and tricyclononenes with different numbers and different positions of silicon-containing substituents has been developed. It has been found that these monomers are readily involved in metathesis polymerization yielding high-molecular-mass polymers possessing good filmforming properties. The addition (vinyl) polymerization of norbornenes is a more complex process; however, the product silylated polynorbornenes exhibit a higher gas permeability than the corresponding metathesis polynorbornenes. By the level of the gas-transport parameters, the silylated addition polynorbornenes obtained in the study are grouped with the most advanced high-permeability polymers. It has been shown that the presence of Me₃Si substituent groups, their amount, and the main-chain structure are responsible for the enhancement of the gas permeability of polynorbornenes. Thus, a series of polymers with a regularly changing structure has been obtained, a result that makes it possible to reveal the polymer structure-property relations.     

New corrosion-resistant materials based on diffusionally chromized carbon steels

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 10, pp. 22–24, October, 1991.     

Sound Absorbing Composites from Nonwoven and Cellulose Submicrofibres

This paper describes possibility of utilization of waste natural fibres in production of sound absorbing composites. Waste flax fibres were modified by enzymatic treatment, after which they became more short and fine. This form of fibres can create good sound absorption. Preliminary studies concerned an application of cellulose fibres after enzymatic treatment as the filling of thermoplastic sound absorbing composites. The conditions of composite manufacturing process from multilayer structure （matrix nonwoven/submicrofibres layer） were developed. The influence of submicroflbres content in the composite on the scale of the improvement of its sound absorption property was investigated. Results showed that for the same conditions of the composite manufacturing process and similar composite thickness, gradual increase in content of that filling leads to adequately increase in sound absorption coefficient of the composites. The composites could be applied among others to accommodations and transport facilities.     

三种催化剂在无纺布专用料中的工业应用对比

本文对比了DQC-401、DQS-1、HR三种聚丙烯催化剂在环管聚丙烯装置中生产高端无纺布专用料PPH-Y40的应用效果,考察此3种聚丙烯催化剂在环管工艺上的适用性,评价对比了其聚合性能,包括聚合活性、氢调敏感性及立构定向性等方面的内容。     

扫描电子显微镜对PP无纺布的分析研究

在低放大倍数下,利用S-3400N扫描电子显微镜观察聚丙烯无纺布试样时,出现试样表面不光滑、边缘呈锯齿状现象。通过改变实验条件、图像记录方式,找到了清晰观察试样原始形貌的方法。与普通慢扫描记录图像方式相比,扫描电子显微镜采用积分式记录图像方式,观察到的试样表面光滑,更接近原始形貌。     

Diesel fuel based on mixtures of petroleum and vegetable raw materials

Сommercial petroleum diesel, distilled biodiesel and jet fuel JP8 were used to prepare the new fuel blend with physicochemical properties meeting the petroleum diesel standards. The proposed fuel blend consisted of 75% (v/v) petroleum diesel, 20% (v/v) distilled biodiesel and 5% (v/v) jet fuel JP8. The humidity of the prepared fuel blend was regulated using the distilled biodiesel. The key physicochemical properties of fuel such as density, kinematic viscosity, conductivity and water content were measured using standard ASTM methods. The storage stability test for the studied samples showed that they remained unchanged even after 30 and 120 days from the preparation moment. The suggested fuel blend composition may be recommended for the industrial applications due to the benefits of adding 20% of the distilled biodiesel. The composition of the fuel blend meets the European directive which proposes adding up to 20% (v/v) of biodiesel to the petroleum based fuels.     

Hybrid materials based on MF-4SK perfluorinated sulfocatonic membranes and platinum

Hybrid nanocomposites based on the MF-4SK membrane and platinum have been obtained by chemical reduction with sodium borohydride of H₂[PtCl₆] in solutions with varying concentration and reaction time. The resulting metal composites have been characterized using standard contact porosimetry and atomic force microscopy techniques and by measuring electric conductivity, permeability, and current-voltage curves. The particle size of metallic platinum has been determined, and the membrane surface roughness factor has been evaluated. Conditions for the preparation of samples with a uniform coating of the membrane surface with a platinum dispersion have been selected. A study of the polarization phenomena has revealed that the parameters of the current-voltage characteristic depend on the orientation of the membrane with respect to proton flux. The presence of platinum on the membrane surface leads to a change in the potential of the transition of the system to the overlimiting state and causes oscillations in the current-voltage curve.     

羧酸配体金属有机骨架材料在吸附脱硫领域的应用进展

介绍了以羧酸为配体设计构筑金属有机骨架材料(MOFs)的合成方法及其对天然气和轻质油品中的硫化氢、噻吩、硫醇、硫醚等有机硫化物的吸附脱除情况。MOF s的主要合成方法有配体拓展、混合配体、模块构筑、后修饰合成,有机配体的结构及中心金属的性质和配位方式对MOFs骨架结构和功能起决定性作用,MOFs更适用于常温、常压对噻吩、硫醚等非活性硫组分非破坏性脱除,在吸附硫化氢、硫醇等活性硫组分时MOFs骨架结构受到极大的破坏。合成高工作容量、高选择性MO Fs用于非活性硫组分的吸附是未来发展的趋势。     

基于路用性能的厂拌热再生工艺研究

主要在室内模拟了再生沥青混合料的施工工艺。对再生混合料的拌合时间、旧料的预热温度以及再生剂的添加方式对再生沥青混合料的路用性能的影响进行了试验研究,并得到了最佳的再生工艺,这对指导工程实践有着很重要的意义。     

Theoretical design and exploration of novel high energy density materials based on silicon

Si-based high energy density materials (HEDMs) have been theoretically studied based on density functional theory and ab initio molecular dynamics simulation. These HEDM compounds have a unique fused-heterocyclic structure centered at Si. A new theoretical technique was used to predict crystal density of HEDMs. It takes into considerations crystal packing and intermolecular interactions. The calculation predicts that the new class of HEDMs can have significantly higher densities than classical energetic materials (from 2.05 to 2.30 g/cm³). Their heats of formation are significantly higher than that of classical energetic materials. In addition, electronic structures of the chemical bonds within these HEDM compounds were theoretically determined and discussed in relation to sensitivity and stability of the compounds. The present research discovers that creatively designed substitution of C by Si in HEDMs can potentially lead to promising candidates with high performance, moderately high thermal stability, and low-impact sensitivity.     

Multilayer Membranes Based on Ceramic Materials—Sol-gel Synthesis, Characterization and Membrane Performance

In nearly all chemical and petrochemical systems, separation of products generally accounts for more than 50% of the capital cost and the greatest part of the energy consumption. It is generally believed that membrane systems can offer benefits in both reducing the energy consumption of the separation stages and lowering the capital expenditure (CAPEX). Microporous ceramic membranes have the potential to overcome the limitation in polymer membranes operation, which has been the subject of a large amount of research worldwide in the last two decades. And most of the research has aimed at the production of the asymmetric multilayered membrane based on amorphous oxides by sol-gel techniques. The paper is to give an overview of publications on ceramic membranes, including less common materials of titania, zirconia, which can be used for pervaporation in corrosive media. Commercially available microporous membranes based on these membrane materials and the membrane economics are also summarized.     

Hybrid materials based on MF-4SK membranes modified with silicon carbide and carbon nanotubes

The effect of hydrophobic silicon carbide nanoparticles and carbon nanotubes on the mechanical and transport properties of MF-4SK perfluorinated cation-exchange membranes has been studied. It has been shown that the modification of the membranes with a small amount of silicon carbide and carbon nanotubes enhances both their mechanical strength and selectivity of transport processes. An increase in the dopant concentration leads to deterioration of these parameters and the destruction of the membranes. This change in the properties is attributed to the implantation of nanoparticles into the hydrophobic membrane matrix, which results in a decrease in its elasticity.