Effect of halloysite nanotubes on thermal and flame retardant properties of polyamide 6/melamine cyanurate composites

In this study, polyamide 6 (PA6) with various contents of halloysite nanotubes (HNTs) and melamine cyanurate (MCA) were prepared by a twin‐screw extruder. The flame retardant and physical properties of PA6 composites were examined. X‐ray diffraction (XRD) patterns of PA6/HNTs and PA6/MCA/HNTs composites showed that HNTs as a nanoscale material dispersed in PA6 whether with MCA or not. Thermo gravimetric analyzer (TGA) results showed the presence of HNTs can improve thermal stability of PA6 and PA6/MCA composites. The incorporation of HNTs seemed to result the increase of crystallinity of PA6 and PA6/MCA composites from the differential scanning calorimetry (DSC) results. The combined of HNTs and MCA that leads to further improvements limiting oxygen index (LOI) value of PA6 to 31.7% exerted a positive effect on flame retardancy of PA6. What's more, some mechanical enhancements of PA6 with adding of HNTs were achieved and HNTs also made the tensile properties of PA6/MCA composites improved. POLYM. COMPOS., 36:892–896, 2015. © 2014 Society of Plastics Engineers     

沸石分子筛膜的合成及其走向生长

本文综述了沸石分子筛膜的各种合成方法。介绍了有机—无机组成结构对沸石分子筛膜的定向生长和载体及其前处理对膜合成的影响。     

快速烧结新技术

将目前电子陶瓷工业中采用的普通烧结方法，通过加快进窑速度和提高烧结区温度，改为快速烧结方法，进窑速度为原来的６倍，烧结温度在原有温度的基础上提高２５～３０℃，使用典型的高频镁镧钛（ＭｇＯ·Ｌａ２Ｏ３·ＴｉＯ２）介质瓷和低频钛酸钡（ＢａＴｉＯ３）介质瓷进行试验验证，结果发现这两种介质瓷的性能均得到了提高，特别是高频介质瓷的介电常数温度系数αε明显地向０方向移动，低频介质瓷的介电常数温度变化率Δε／ε（－５５℃～＋８５℃）显著降低，这是因为电子陶瓷材料可以认为是由晶粒和隔开它们的玻璃质晶界，以及少量气孔组成的，快速烧结使瓷体的晶粒尺寸大小均匀，气孔密度明显减小，玻璃质晶界性能得到提高的缘故，其中尤以玻璃质晶界对高频介质瓷的介电常数温度系数αε或低频介质瓷的介电常数温度变化率Δε／ε（－５５℃～＋８５℃）影响显著，热历史对玻璃的结构和性能有很大的影响，快速烧结改变了热历史从而导致了玻璃结构和性能的改变，使玻璃在低温（－５５℃）和高温（＋８５℃）时的介电常数和在常温（２５℃）时的介电常数相比变化较小。同时，采用快速烧结电子陶瓷的新工艺，可以大量地节约能源，节省劳动力，提高经济效益。     

A new two-dimensional experimental apparatus for electrochemical remediation processes☆

Electrochemical extraction of contaminants from soils is a promising soil decontamination technology. Various experiments have been conducted to study electrochemical reactions and geochemical processes in the electro-chemical extraction using different experimental apparatuses. This paper presents the development of a new closed two-dimensional (2D) apparatus that can better simulate the field application of the technology and ac-curately monitor the most important electrochemical parameters to understand the process. The innovative fea-tures of the new apparatus include the outer and inner electrodes designed to apply a non-uniform electrical field across the specimen as in the field electrochemical remediation process, the probes installed to measure the 2D distribution of electrical voltage, and the gas and fluid volume measurement devices used to accurately monitor the gas generation and electroosmotic flow rates at both electrodes as a function of time. The components of this new apparatus and the features of each component are described. The operating procedure and some typical re-sults from three experiments with the apparatus are demonstrated. The results show that the variation of the gas generation rate is in good agreement with the electric current. Their relation provides a valid evaluation for elec-trochemical behavior of the system and Faraday's laws of electrolysis. The 2D profiles of cadmium concentration and voltage distribution at the end of the experiment reveal the great effects of a non-uniform electrical field on the contaminant mobilization.     

导流装置对含油雾颗粒气流影响的数值模拟

使用数值模拟分析的方法,探究在加装角钢和百叶这两种导流装置的情况下,静电式油雾净化器箱体内气流的变化。结果显示,在含油雾颗粒气流质量流量相同的前提下,角钢对箱体四周漩涡具有抑制作用,因而减少了漩涡区对气流造成的能量损耗。     

硅藻土对苯丙内墙涂料性能的影响

为考察硅藻土对内墙涂料性能的影响,制备了硅藻土基苯丙内墙涂料,通过配方设计,分别考察了硅藻土粒径和添加量对苯丙内墙涂料的涂膜表观、耐冲击性及柔韧性的影响,并对涂膜进行了吸放湿实验。结果表明:硅藻土可用于制备具有调湿功能的内墙涂料,其涂膜具有良好的吸放湿性能。实验确定了硅藻基苯丙内墙涂料的最佳配方。     

Emulsifying and foaming properties of native and chemically modified peptides from the 2S and 12S proteins of rapeseed (Brassica napus L.)

The 2S and 12S proteins of rapeseed were isolated and subsequently hydrolyzed by pepsin or a combination of pepsin plus trypsin. The resulting hydrolysates had a 15% degree of hydrolysis and were purified by gel filtration chromatography in order to obtain homogeneous peptide fractions. Three major fractions, having an average peptide chain length of 7.5–11 amino acids, were recovered. Purified peptide fractions were acylated with butyric anhydride and sulfamidated with p-toluenesulfonyl chloride. The degree of modification was always higher than 90%. Emulsifying and foaming properties of native and chemically modified peptides were studied and compared to those of sodium dodecyl sulfate (SDS) as standard. A peptide fraction from the 15% hydrolysis of the 12S protein exhibited the best foaming properties. After sulfamidation, this peptide fraction showed a foam formation similar to that of SDS. Whereas the attachment of toluene groups generally improved the surface properties, the incorporation of an aliphatic chain of four atoms of carbon was detrimental in most of the cases. On the other hand, none of the native or hydrophobized peptide fractions was able to form a stable emulsion.     

液下气泡检漏方法研究

探讨了液下气泡检漏法的基本原理、泄漏率计算方法以及检漏精度和分辨率。应用该方法对石棉橡胶垫片的泄漏率进行了测定 ,试验结果与采用集漏空腔增压法测得的泄漏率具有较好的可比性。分析了液下气泡法用于工程实际时应注意的问题。     

双效变压精馏节能技术的应用

以新开发设计的C－1305塔和C－1303塔联塔取代耗能大户DA－303塔,使C－1305塔顶热物为的汽化潜热在C－1303塔的再沸器中得到二次利用,从而形成双效变压精馏节能系统达到节能增效的目的。     

稀土SO4^2—／ZrO2—TiO2复合固体超强酸对乙酸酯的催化合成研究

采用低温陈化法制得稀土SO4^2-/SrO2-TiO2复合固体超强酸,应用于乙酸酯类的合成中,在反应时间为2.5h,醇酸摩尔比为1：1.5时,催化剂用量为反应物质量的1.4%-1.5%,酯化率可高达97.4%。