PET／PEN共混物结构和性能的研究

在控制熔融共混温度和时间的前提下制备了一系列配比不同的PET／PEN共混物,通过NMP、WAXS、DSC和DMA等手段对共混物的结构特别是酯交换反应的情况进行了研究。发现在所选定的低熔融温度、较短熔融共混时间等条件下,PET与PEN之间基本未发生酯交换反应,熔融挤出产物中PET和PEN两组分仍然保持着各自分子链的规整性,在加热时仍然可以独自结晶。     

抓住关键问题落实节能措施

对我公司电化整流设备运行的状况进行了总结,介绍了为提高设备出率,降低消耗,安全稳定运行而采取的相应技术措施。     

改性淀粉油田废水处理剂应用可行性分析

针对我国油田废水处理过程中普遍存在着的费用偏高,处理效果不够理想以及处理后的二次污染问题,采用改性淀粉分别对四种典型油田废水的处理效果,药剂的毒性及其经济可行性进行了系统的考察和分析。研究结果表明,此类化合物的综合评估效果优于聚丙烯酰胺类水处理剂,将其用于石油工业废水的净化处理是可行的。     

1,3-二氯-5,5-二甲基海因的合成及杀菌性能研究

以丙酮氰醇为原料经Bacherer bergs环化反应及改进的氯化反应合成出了 1,3 二氯 5 ,5 二甲基海因 ,并对其杀菌性能进行了初步研究     

Low-temperature dyeing of meta-aramid fabrics pretreated with 2-phenoxyethanol

In this study, meta-aramid fibres were pretreated with 2-phenoxyethanol under different conditions to investigate the effect of 2-phenoxyethanol on the dyeing of aramid at low temperature (95 °C). Structural alteration of the pretreated fibres was reflected by thermogravimetry and Fourier transform infrared spectroscopy, indicating more H-bonds, lower crystallinity, and slightly lower thermal stability. The change in structure showed that 2-phenoxyethanol combined with the fibre macromolecules and resulted in swelling of the fibre. Creation of a biphasic system through the addition of 2-phenoxyethanol to the dyeing solution resulted in the cationic dye being partitioned more towards the 2-phenoxyethanol-rich phase than the aqueous phase. The cross-sections of the dyed fibre suggested that the meta-aramid fibre could be dyed more thoroughly with an appropriate concentration of 2-phenoxyethanol. The colour value of aramid fabric was tested by varying the concentration of 2-phenoxyethanol and the temperature of pretreatment, indicating a dramatic improvement in dyeing performance to aramid after 2-phenoxyethanol pretreatment. 2-Phenoxyethanol pretreatment and low-temperature dyeing can overcome the problems of chemical and energy waste while producing a satisfying colour.     

Flame-retardant properties and synergistic effect of ammonium polyphosphate/aluminum hydroxide/mica/silicone rubber composites

The flammability behaviors of ammonium polyphosphate/aluminum hydroxide/mica/silicone rubber (APP/Al[OH]₃/mica/SiR) ceramifying composites containing APP, Al[OH]₃, and mica are investigated by cone calorimeter test. The thermal degradation and the synergistic effect of APP/Al(OH)₃/mica/SiR composites are investigated by thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. APP/Al(OH)₃/mica/SiR composites with 25 wt% of APP, 20 wt% of Al(OH)₃, 25 wt% of mica, and 30 wt% SiR presents a much lower total heat release, the value of peak heat release rate (PHRR), the maximum average heat release rate, the longest time to ignition, and time to the PHRR (t_PHRR), compared with the flame-retardant properties from composites with filler of APP and mica or APP and Al(OH)₃ alone. The results indicate that there is an excellent synergism in APP, Al(OH)₃, and mica, which endows APP/Al(OH)₃/mica/SiR composites with both good flame retardancy and fire prevention. The study on the synergism effect between fire prevention and flame retardancy of APP/Al(OH)₃/mica/SiR composites indicates that compounds containing P-O-Al are formed due to the reaction between APP and Al(OH)₃ during combustion in the early stage and a coherent, dense, and sealed structure is formed due to the reaction in mica, phosphates, and the thermal decomposition products of SiR during combustion in the later stage.     

带有相变气固二相混合对流的数值研究

本文提出了一种描述带有相变的气固二相混合对流问题的数学模型和数值计算方法。高温融溶液滴在逆向气体流场中经历有三个阶段:液相冷却,固化和固相冷却。对于液滴的运动边界(相变)问题,本文提出了一种变时间步长焓法进行求解。气体颗粒二相流动、采用Eulerian-Lagr-aigian方法。对于Rayligh数大于10~6的湍流,本文应用了两方程(K-ε)模型。修正的SIMPLE方法和四阶Rlunge-Kutta法用来进行数值迭代求解。本文对一种直径为20米。高度为50米的尿素造粒塔作了简化,并完成了数值计算。文章表明浮升力对有相变的运动液滴历程有重要影响。本文所得的一些结果分析对工业尿素塔的设计有指导意义。     

Topology and porosity control on zirconium–fumarate frameworks boosting xenon/krypton separation

The designability and ultrahigh stability of zirconium–organic frameworks make them attractive adsorbents for noble gases xenon (Xe) and krypton (Kr), but their Xe/Kr separation performance needs to be further enhanced. In this study, we rationally control the topology and porosity of zirconium–fumarate frameworks by simply changing the synthesis conditions, and successfully construct an adsorbent (named as MIP-203-F) with one-dimensional pore instead of the original cage-like fcu metal–organic framework MOF-801. The Xe/Kr separation performance of MIP-203-F is thoroughly evaluated by isotherm measurements and breakthrough experiments, while the adsorption mechanism is elucidated in detail by Monte Carlo and density functional theory calculations. Due to the uniform pore with suitable size and abundant polarization groups, MIP-203-F can differentially polarize and recognize atomic Xe/Kr gases, and establishes a new record among zirconium–organic frameworks for the capture and separation of Xe/Kr.     

Oxygen enrichment from air through multilayer thin low‐density polyethylene films

Several multilayer thin low‐density polyethylene (LDPE) films were fabricated by blown thin film having a thickness of 7 μm and an area of 130 cm². They were characterized for their oxygen‐enrichment performance from air by a constant pressure–variable volume method in a round permeate cell with an effective area of 73.9 cm². The relationship between oxygen‐enrichment properties, including oxygen‐enriched air (OEA) flux, oxygen concentration, permeability coefficients of OEA, oxygen, nitrogen, as well as separation factor through the multilayer LDPE films, and operating parameters, including transfilm pressure difference, retentate/permeate flux ratio, temperature, as well as layer number, are all discussed in detail. It is found that all of the preceding oxygen‐enrichment parameters increase continuously with an increase of transfilm pressure difference from 0.1 to 0.65 MPa, especially for the trilayer and tetralayer LDPE films. The oxygen concentration and separation factor appear to rapidly increase within the retentate/permeate flux ratio below 200, and then become unchangeable beyond that, whereas the OEA flux and the permeability coefficients of OEA, oxygen, and nitrogen seem to remain nearly constant within the whole retentate/permeate flux ratio investigated, especially for the monolayer and bilayer LDPE films. The selectivity becomes inferior, whereas the permeability becomes superior, as the operating temperature increases from 23 to 31°C. The highest oxygen concentration was found to be 44.8% for monolayer LDPE film in a single step with air containing oxygen of 20.9% as a feed gas and operating pressure of 0.5 MPa at a retentate/permeate flux ratio of 340 and 23°C. The results demonstrate a possibility to prepare an oxygen‐enriching membrane directly from air, based on the easily obtained thin LDPE films. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3013–3021, 2002; DOI 10.1002/app.2331     

结晶法净化湿法磷酸生产磷酸二氢钾研究

研究了三聚氰胺结晶法净化湿法磷酸复分解生产精细磷酸二氢钾工艺中磷酸三聚氰胺与氯化钾反应生产磷酸二氢钾的工艺条件。采用二次正交组合实验设计，对反应过程中反应温度，反应时间，搅拌速度，氯化钾用量，氯化钾初始浓度等诸因素的一次作用，二次作用及交互作用对五氧化二磷转化率的影响进行了研究，得到了适宜的工艺条件，所得磷酸二氢钾达到HG2321－91质量标准。