巴斯夫计划扩大北美增塑剂生产

巴斯夫公司计划投资6000万美元进行一系列生产装置建设以扩大北美增塑剂业务，包括在美国的得克萨斯州Pasadena新建一套邻苯二甲酸酯生产厂，新厂将可以向北美市场供应巴斯夫的新型增塑剂邻苯二甲酸二丙基庚酯(DPHP)。巴斯夫还将对Pasadena的现有12．5万吨／年2-乙基己醇(2-EH)生产装置改造成12万吨／年的2-丙基庚醇(2-PH)生产装置，为新建DPHP提供原料。     

Gel electrolytes with ionic liquid plasticiser for electrochromic devices

The comparative performance of conducting polymer electrochromic devices (ECDs) utilising gel polymer electrolytes (GPEs) plasticised with ethylene carbonate/propylene carbonate or (N-butyl-3-methylpyridinium trifluoromethanesulphonylimide (P₁₄TFSI) has been made. Lithium perchlorate and lithium trifluoromethanesulphonylimide salts were used in the GPEs to provide enhanced ionic conductivity and inhibit phase separation of the polyethyleneoxide (PEO) and plasticiser. ECDs were assembled from cathodically colouring, polyethylenedioxythiophene (PEDOT), and anodically colouring, polypyrrole (PPy), conducting polymer electrochromes deposited by vapour deposition. The photopic contrast switching over the visible light spectrum, switching speeds and device stability of the ECDs were obtained. These studies demonstrate that the ionic liquid (IL) plasticised GPEs are a suitable replacement for pure IL based devices and volatile organic solvent plasticisers based upon ethylene carbonate/propylene carbonate mixtures.     

低温锌-锰系磷化工艺

采用磷酸二氢锌、酸式磷酸锰等为主要原料,加入适当的磷化促进剂,研究成功了一种性能全面的钢铁磷化工艺,检测了磷化膜的性能。探讨了磷化液主要成分和磷化工艺条件对磷化膜质量的影响。结果表明,所形成的磷化膜成灰黑色,结晶细致、均匀,耐蚀性好,与涂层附着力好,工艺维护简单,沉渣少,适用于各类钢铁件涂装前的处理。     

Low glass transition temperature aliphatic polyurethanes

Summary The present paper deals with the single step syntheses of a few aliphatic polyurethanes using some simple glycols like ethylene, propylene, 1,3- and 1,4-butylene glycols and two different bis(chloromethyl) compounds viz., 1,4-bis(chloromethyl)-2,5-dimethyl benzene (I), and 1,5-bis(chloromethyl)-2,4-dimethyl benzene (II). The glass transition temperatures, T_g, of these polymers were determined using dilatometric techniques and they ranged from –12 to –48°C. The polyurethanes derived from 1,4-butylene and ethylene glycols were amorphous gums with T_g well below –30°C.     

Low temperature oxidation of athabasca bitumen

The kinetics of low temperature oxidation in the Athabasca oil sands were investigated over the temperature range 373 K to 459 K. Oxidation experiments, in which the sand-free bitumen was vigorously stirred to obtain a homogeneous oxygen concentration throughout the bitumen, were carried out. It was concluded that the oxidation reaction is governed by three different kinetic expressions depending on temperature and past oxidation history. These are: (i) a high rate first order regime which is obeyed at low extents of oxidation and at temperatures below approximately 423 K; (ii) a second order regime, obeyed at low extents of oxidation and at temperatures greater than 423 K; and (iii) a low rate first order regime, obeyed for extents of oxidation greater than 1.7 moles O₂/kg bitumen over the entire temperature range investigated. The partial molar enthalpy of low temperature oxidation was also evaluated, and was found to be constant over the range of oxidation extents studied.     

Low temperature gasification using lattice oxygen

Low temperature pyrolysis and gasification has been investigated based on the chemical looping combustion (CLC), where insufficient amount of lattice oxygen was reacted with hydrocarbons. Metal oxides such as nickel oxide, iron oxide and titanium oxide were used as lattice oxygen source and were coated on silica gel or porous aluminum. Single column reactor was used for experiments and 36.1 mmol of polyethylene was dropped to the column whose temperature was ranged from 693 to 1073 K. For the pyrolysis, hydrogen yield was 100% of polyethylene contained hydrogen, while methane, CO and CO₂ were minor products and almost half of the supplied carbon was deposited on the particle surface. On the other hand, for the steam gasification, 2-3 mol of the hydrogen was generated from 1 mol of carbon and almost no carbon deposition was observed. It is found that no wax and heavy tar was observed in the exhaust. Therefore, the lattice oxygen was able to be applied to the low temperature gasification of hydrocarbons.     

Low temperature growth of gallium nitride

Radio frequency reactive sputtering was used to produce gallium nitride films on glass and silicon substrates at close to room temperature. The films were analysed by transmission electron microscopy and Rutherford backscattering spectroscopy. The films were found to consist of nanocrystalline wurtzite GaN with c-axis-oriented columnar grains growing perpendicular to the substrate. Varying the N₂:Ar sputtering gas ratio was found to have little effect on the grain size. Annealing the films at 400°C was found to increase the E₁(TO) signal observed by Fourier transform IR spectroscopy and to reduce the porosity of the columnar structure.     

Low temperature defect chemistry of oxides

Defect chemistry at lower temperatures, e.g. room temperature, is systematically described, at which the oxygen exchange reaction is no longer reversible. Analytical relations, numerical results, case studies as well as technological and scientific relevance are highlighted. It is pointed out that the low temperature defect chemistry also offers a quantitative basis to manipulate charge carrier and defect concentrations and related physical properties of oxide electroceramics.     

Low temperature flash vaporization for desalination

The feasibility of desalination by low pressure vaporization of seawater at temperatures between 26°C and 32°C was demonstrated in a pilot plant. The plant operated at vacuum pressures between 1.3 KPa and 2.3 KPa. The saline water was sprayed into the vaporizer as fine droplets using a swirl nozzle and evaporated at the low pressure. The maximum flow rate was 1,000 1/h. Condensation of the vapor so formed, was carried out in a shell and tube heat exchanger. The yield of fresh water was up to 4% as predicted by theory. The quality of the condensed water was excellent. The investigation demonstrated a novel concept of devising a desalination system by using warm water from the upper strata of the ocean for flash vaporization at low pressures and condensing the vapors using cold water from the lower strata of the ocean. The performance of the pilot plant was determined for different feed water temperatures, vacuum and water injection pressures.     

氧化铝陶瓷低温烧结的研究现状和发展前景

本文综述了氧化铝陶瓷低温烧结的研究现状,包括粉体的制备,处理,成型及烧结工艺,并对此领域做了相应的设想和展望。     

Low firing temperature ceramic for microcircuit substrates

Methods for fabricating substrates based on low-temperature (firing temperature below 1000°C) ceramic, fired together with a deposited metal coating, are examined. Materials which are promising for use as low-temperature simultaneously fired ceramic (LSC) in the systems B₂O₃-CaO-SiO₂ and B₂O₃-CaO-Al₃O₃ are proposed.     

Low temperature cure of vinyl ester resins

Vinyl ester resins are well known for their versatility as a composite matrix. With the development of a promising room temperature molding technology, vacuum-assisted resin transfer molding, e.g. Seemann Composite Resin Infusion Molding Process (SCRIMP), the processability of vinyl ester resins at low temperatures has attracted considerable attention from the composite industry. The objective of this paper is to provide a better understanding of the reaction kinetics of this resin system at low temperatures. In this study, a differential scanning calorimeter (DSC) coupled with a Fourier transform infrared (FTIR) spectrometer was employed to measure the reaction profile of a vinyl ester resin with different promoter and styrene contents. A kinetic model based on the free radical co-polymerization mechanism was developed for simulating the reaction rates and conversions of styrene vinyl and vinyl ester vinylene groups. The model parameters were determined from several FTIR experiments under isothermal conditions. This model, in conjunction with heat transfer analysis, was able to successfully predict the temperature profiles during curing in two SCRIMP molding cases based on groove type resin distribution system.     

Low temperature transitions in a crosslinked urethane

We have investigated the low temperature transitions in a urethane prepolymer crosslinked with various amines and triols by measuring their dynamic mechanical properties over a temperature range of 25°C to approximately ? 190°C. In the formulations studied, a low temperature transition was observed near ? 140°C and the transition was shown to be related to the electronic and steric influences of the curing agent structure at the crosslink site. A quantitative relationship was demonstrated between the low temperature transition peak intensity and the polymer's crosslink density. The above relationships were derived from torsion pendulum and solvent swell experimentation.     

Low temperature electrochemical oxidation of sulfur dioxide

The low temperature electrochemical oxidation of sulfur dioxide on carbon gas diffusion electrodes modified with cobalt phthalocyanine (CoPc) was studied. It was found that when operating with mixtures of air containing up to 20% by volume SO₂ a basic problem of the electrooxidation of SO₂, namely its permeation into the electrolyte, can be resolved. It is demonstrated that sulfur dioxide can be oxidized in the presence of air on active carbon, modified with cobalt phthalocyanine without external current at room temperature. The electrocatalytic character of the process is established and the rate dependence on the concentrations of H₂SO₄ and SO₂ up to 0.30 vol % in air is displayed. An original method for the cold oxidation of SO₂ to sulfuric acid is proposed.