Melt spun matrix fibers of toughened polypropylene copolymers modified by high energy electrons

Binary blends of polypropylene (PP) and ethylene‐octene copolymer (EOC) are prepared by continuous electron‐induced reactive processing at various mass ratios of the blend components and various doses without adding of any grafting agents. The influence of mass ratio and dose is investigated in order to get the optimum processing behavior of toughened PP as well as optimum properties of resulting fibers. It is found that toughened PP with a PP/EOC blend ratio of 97.5–2.5  mass % can be used advantageously as a matrix component for the process of online spinning of glass fiber/toughened PP hybrid yarns. Such hybrid yarns belong to one of the most advanced production methods for the manufacturing of fiber reinforced thermoplastic composites with an increased mechanical performance. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44011.     

Conversion of Nuclear Waste to Molten Glass: Cold‐Cap Reactions in Crucible Tests

The feed‐to‐glass conversion, which comprises complex chemical reactions and phase transitions, occurs in the cold cap during nuclear waste vitrification. To investigate the conversion process, we analyzed heat‐treated samples of a simulated high‐level waste feed using X‐ray diffraction, electron probe microanalysis, leaching tests, and residual anion analysis. Feed dehydration, gas evolution, and borate phase formation occurred at temperatures below 700°C before the emerging glass‐forming melt was completely connected. Above 700°C, intermediate aluminosilicate phases and quartz particles gradually dissolved in the continuous borosilicate melt, which expanded with transient foam. Knowledge of the chemistry and physics of feed‐to‐glass conversion will help us control the conversion path by changing the melter feed makeup to maximize the glass production rate.     

Polymerelektrolytmembranen für Hoch‐ und Niedertemperatur‐Brennstoffzellen aus strahlungsinduzierter Pfropfcopolymerisation

Radiation‐induced graft copolymerization of hydroxyethyl methacrylate with hydroxyethyl acrylate, acrylic acid or glycidyl methacrylate on ethylene tetrafluoroethylene (ETFE) films allow for tailor‐made synthesis of membranes for high and low temperature fuel cell applications. According to the operating temperatures proton conductivity may be achieved via doping with phosphoric acid or a two‐step sulfonation of the functional monomers. Fuel cell tests provide power densities and internal resistances, which indicate that the membranes are suitable for high and low temperature fuel cells.     

Regime transition in viscous and pseudo viscous systems: A comparative study

A comprehensive quantitative study on the effect of liquid viscosity (1 ≤ µ_L ≤ 1149 mPa‐s) on the local flow phenomena of the gas phase in a small diameter bubble column is performed using ultrafast electron beam X‐ray tomography. The internal dynamic flow structure and the bubble size distribution shows a dual role of the liquid viscosity on the hydrodynamics. Further, the effect of solid concentration (C_s = 0.05, 0.20) on the local flow behavior of the gas phase is studied for the pseudo slurry viscosities similar to the liquid viscosities of the gas–liquid systems. The effects of liquid and pseudo slurry viscosities on flow structure, bubble size distribution, and gas phase distribution are compared. The bubble coalescence is significantly enhanced with the addition of particles as compared to the system without particles for apparently same viscosity. The superficial gas velocity at which transition from homogeneous bubbly to slug flow regime occurs is initiated by the addition of particles as compared to the particle free system for apparently same viscosity. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3079–3090, 2014     

Higher Hydrocarbon Production through Oxidative Coupling of Methane Combined with Hydrogenation of Carbon Oxides

In the production of higher hydrocarbons, combining oxidative coupling of methane (OCM) with hydrogenation of the formed carbon oxides in a separate reactor provides an alternative to the currently applied methane conversion to syngas followed by Fischer‐Tropsch synthesis. The effects of CH₄:O₂ feed ratio in the OCM reactor and partial pressures of H₂ or/and H₂O in the hydrogenation reactor were analyzed to maximize production of C₂₊ hydrocarbons and reduce CO_x formation. The highest C₂₊ yield was achieved with low CH₄:O₂ feed ratio for OCM and removal of the formed water before entering the hydrogenation reactor.     

Powder coating of veneered particle board surfaces by hot pressing

The powder coating of veneered particle boards by the sequence electrostatic powder application – powder curing via hot pressing is studied in order to create high gloss surfaces. To obtain an appealing aspect, veneer sheets were glued by heat and pressure on top of particle boards and the resulting surfaces were used as carrier substrates for powder coat finishing. Prior to the powder coating, the veneered particle board surfaces were pre-treated by sanding to obtain good uniformity and the boards were stored in a climate chamber at controlled temperature and humidity conditions to adjust an appropriate electrical surface resistance. Characterization of surface texture was done by 3D microscopy. The surface electrical resistance was measured for the six veneers before and after their application on the particle board surface. A transparent powder top-coat was applied electrostatically onto the veneered particle board surface. Curing of the powder was done using a heated press at 130 °C for 8 min and a smooth, glossy coating was obtained on the veneered surfaces. By applying different amounts of powder the coating thickness could be varied and the optimum amount of powder was determined for each veneer type.     

用于化学纤维加工的气圈控制系统的发展

在AiF研究项目的(AiF编号:14315)的范围内,通过在邓肯道夫纺织工艺研究所(ITV)对锭子的开发,即应用旋转纱线制动装置和经过优化的钢领钢丝圈系统,研究了改善加工化学纤维的环锭纺设备的性能的可能性.