聚氨酯预聚物改性酚醛泡沫塑料脆性的研究

采用聚氨酯预聚物对酚醛泡沫塑料进行改性，研究了预聚物粘度、用量对泡沫粉化程度和回弹性的影响。结果表明：预聚物的粘度越低，对酚醛泡沫的粉化性的改善效果越好；当预聚物的质量分数为3％时，改性泡沫的粉化程度仅为未改性的40％，且使泡沫具有一定的弹性，回弹率大于60％；聚氨酯预聚物对酚醛泡沫塑料的改性机理不是简单的物理共混，同时伴有共聚反应发生。     

三硅氧烷表面活性剂

介绍了三硅氧烷表面活性剂的结构、合成、性能和应用。     

Separation and determination of cadmium in water by foam column prior to inductively coupled plasma optical emission spectrometry

The sorption profile of cadmium (II) ions from aqueous iodide media onto procaine hydrochloride (PQ⁺·Cl⁻) treated polyurethane foams (PUFs) solid sorbent was studied. PQ⁺·Cl⁻ treated PUFs solid sorbent was found suitable and fast for Cd²⁺ uptake as [CdI4]_aq²⁻. Thus, removal of Cd²⁺ at trace levels by the sorbent packed columns was achieved. The sorbed Cd²⁺ species onto packed column were recovered with HNO₃ (10.0 mL, 1.0 mol L⁻¹) prior determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). Plot of Cd²⁺ ions concentration was linear in the range 0.05–15 μg L⁻¹. The limits of detection and quantification of Cd²⁺ were found 0.01 μg L⁻¹ and 0.033 μg L⁻¹, respectively. Such limits could be improved to lower values by retention of Cd²⁺ species from large sample volumes of the aqueous phase at the optimized conditions. The relative standard deviation of the packed column for the extraction and recovery of standard aqueous solutions (0.1 L) containing 1.0 and 5.0 μg L⁻¹ (n = 3) of Cd²⁺ ions at flow rate of 5.0 mL min⁻¹ were 1.98 and 2.9%, respectively. The method was validated by analysis of Cd in certified reference materials (CRMs) IAEA-Soil-7 and TMDW water and wastewater samples.     

搅拌与混合对兽疫链球菌发酵生产透明质酸的影响

研究了透明质酸的流变学特性以及搅拌和混合对兽疫链球菌发酵生产透明质酸的影响。结果表明：透明质酸溶液属于典型的非牛顿凯松流体;搅拌转速和透明质酸浓度对气液传氧速率有很大影响;在较高的搅拌速率下发酵时可以得到较高的透明质酸产量,650 r·min^-1时透明质酸产量为4.1 g·L^-1,产率系数为0.08 g·g^-1;用有效搅拌模型分析发酵过程发现,只有在高搅拌转速时发酵体系才处于全部混合状态。     

耐高温低伤害清洁水性稠化剂的制备及性能

针对高温储层压裂需求,以丙烯酰胺（AM）、丙烯酸（AA）、十八烷基二甲基烯丙基氯化铵（ODAAC）和十八烷基甲基丙烯酸酯（SMA）为原料制备了一种疏水缔合聚合物（AAOS）,再使用低分子醇（乙二醇、丙三醇、正丙醇）、表面活性剂（椰子油脂肪酸二乙醇酰胺和十二烷基硫酸钠）和AAOS配制开发一种“自交联”耐高温清洁水性稠化剂（FPM-1）。SEM结果表明,质量分数为0.30 %的FPM-1水溶液能显著增强AAOS聚合物分子间的疏水缔合交联作用,增大聚合物的流体力学体积。通过对FPM-1的溶解性、表观黏度、耐盐性、流变学测试表明,FPM-1溶液为高黏弹性流体,悬砂性能好;质量分数为0.27 %的AAOS在水中的溶解时间为7 min,最终黏度为90 mPa·s,质量分数为0.60 %的FPM-1（具有等效聚合物含量）在水中的溶解时间仅需3 min,且最终黏度为165 mPa·s,表明FPM-1体系能显著提高聚合物的黏度和溶解速度。在90℃,170 s-1条件下剪切1 h后,质量分数为0.27 %的AAOS水溶液的黏度为51 mPa·s,质量分数为0.60 %的FPM-1水溶液黏度为77 mPa·s;质量分数为1.40 %的FPM-1水溶液在180℃,170 s-1条件下剪切1 h,最终黏度为53 mPa·s;质量分数为0.60 %的FPM-1在5×104 mg/L矿化度盐水中黏度保持率为60 %,因此,FPM-1水溶液具有优异的耐盐、耐高温、耐剪切性能。通过对破胶液的表/界面张力测试表明,FPM-1体系破胶液具有低的表/界面张力,有利于破胶液的返排和回收再利用。     

无固相完井液用甲酸盐溶液性能综述

甲酸盐完井液因其对环境危害小,近年来引起了国际上的广泛关注。本文综述了甲酸盐的性质,及其在井下环境中的变化。     

The Finite Element Simulation of Polymer Coextrusion Based on the Slip Boundary

The three-dimensional flow of Non-Newtonian polymer melts in coextrusion dies was analyzed based on finite element simulations. The analysis considered the slip both die wall-polymer and polymer-polymer interface. The slip boundary condition is founded based on the Generalized Navier slippage model. The effects of die wall roughness on the interface were examined farther. It is found that decreasing the roughness of the fluid path can make the velocity field more uniform and the interfacial offset less. If consider the interface alip of two melts, the homologous of interface-slip coefficient and die-wall slip coefficient may ensure the stabilization of the interface.     

Preparation of water-soluble nanographite and its application in water-based cutting fluid

Water-soluble nanographite was prepared by in situ emulsion polymerization using methacrylate as polymeric monomer. The dispersion stability and dispersion state of graphite particles were evaluated by UV-visible spectrophotometry and scanning electron microscopy, respectively. The water-soluble nanographite was then added into the water-based cutting fluid as lubricant additive. The lubrication performance of water-based cutting fluid with the nanographite additive was studied on four-ball friction tester and surface tensiometer. Results indicate that the modification method of in situ emulsion polymerization realizes the uniform and stabilized dispersion of nanographite in aqueous environment. The optimal polymerization condition is 70°C (polymerization temperature) and 5 h (polymerization time). The addition of nanographite decreases the friction coefficient and wear scar diameter by 44% and 49%. Meanwhile, the maximum non-seizure load (P_B) increases from 784 to 883 N, and the value of surface tension (32.76 × 10⁻³ N/m) is at low level. Nanographite additive improves apparently the lubrication performance of water-based cutting fluid.     

Computational modelling of industrial pulp stock chests

Agitated pulp stock chests are the most widely used mixers in pulp and paper manufacture. Stock chests are used for a number of purposes, including attenuation of high‐frequency disturbances in pulp properties (such as mixture composition, fibre mass concentration, and suspension freeness) and are designed using semi‐empirical rules based largely on previous experience. Tests made on both laboratory and industrial‐scale pulp chests indicate that they are subject to non‐ideal flows, including channelling and creation of dead zones. In the present work, a commercial computational fluid dynamic (CFD) software (Fluent) is used to model two industrial pulp stock chests. The first chest is rectangular, agitated using a single side‐entering impeller, and feeds a mixture of chemical pulps at 3.5% mass concentration (C_m) to a papermachine. The second chest has rectangular geometry, with a mid‐feather wall used to direct suspension flow through a U‐shaped trajectory past four side‐entering impellers. This chest is used to remove latency from a C_m = 3.5% thermomechanical pulp suspension ahead of stock screening. For CFD computations, pulp rheology was described using a modified Hershel–Buckley model. Steady‐state simulations were made corresponding to process conditions during mill tests. The calculated steady‐state flows were then used to determine the dynamic response of the virtual chests and then compared with experimental measurements and found to agree reasonably well. The computed flow fields provided insight into mixing processes occurring within the chests, showing cavern formation around the impellers (which reduced the agitated volume available for mixing). Mass‐less particle tracking, using the steady‐state flow field, gave insight into the stagnant regions and bypassing zones created in the vessels. This paper discusses difficulties encountered in characterising the mixing (both experimentally and computationally) and the limitations of the industrial data.