Studies on crystallization behaviors and crystal morphology of polyamide 66/clay nanocomposites

X‐ray diffraction methods, DSC thermal analysis, and polarized light microscopy (PLM) were used to investigate the structural changes of nylon 66/clay nanocomposites. PA 66/clay nanocomposites were prepared by the method of melt intercalation. The results indicate that the addition of the intercalated organo‐montmorillonite (OMMT) can induce generation of the β‐form crystal of PA 66 and substantially affect the arrangement of molecules in the α‐form crystal, although the crystallinity scarcely changes. Also, the DSC results indicate that the addition of OMMT in the PA 66 matrix leads to increases of crystallization temperatures and the full width at half maximum (FWHM) of the exothermic peaks. Moreover, the viscosity factor is the main influence on FWHM of the exothermic peaks of PA 66/clay nanocomposites. The results of nonisothermal crystallization kinetics show that OMMT has the effect of heterogeneous nucleation and leads to the decrease of the size of the spherocrystal. The heterogeneous nucleation effects of OMMTs influence the mechanism of crystallization and the growth mode of PA 66 crystals. PLM photographs verify that the size of spherocrystal is decreased and visually confirm the theory of crystallization kinetics. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 756–763, 2005     

高温高压设备瞬态密封分析的三维力学与传热学模型

以大型加氢反应器的高压法兰密封结构为研究对象，建立了瞬态及稳态密封分析的三维力学与传热学模型，主要解决了螺栓载荷的动态模拟和螺栓孔内空气环层的传热计算问题。利用该模型对加氢反应器的瞬态及稳态密封状况进行了计算。     

超高性能混凝土与水泥基材料界面粘结性研究进展

随着混凝土结构服役年限增长和外部环境导致的混凝土结构损伤,结构将难以达到设计要求,需对既有结构进行修复加固,或采用新型组合结构替换原结构.超高性能混凝土(Ultra High Performance Concrete,UHPC)作为一种超高强度、良好韧性和优异耐久性的水泥基复合材料,将其应用到既有混凝土结构的修复加固中,有望成为良好的解决方案,但两种材料之间可靠的界面粘结是其中的关键.通过对国内外UHPC与水泥基材料界面性能试验和数值模拟研究进展的系统梳理和总结,阐述了两种混凝土材料界面粘结性能试验方法,分析了影响UHPC与水泥基材料组合结构界面粘结性因素,包括基底混凝土表面处理方式、界面剂、UHPC材料性能等,探讨了UHPC界面性能数值模拟中粘结滑移关系及UHPC损伤模型的选择.最后,对UHPC与水泥基材料界面粘结今后的研究方向提出了一些建议,希望能为UHPC在实际修复加固工程中的应用提供指导和帮助.     

Study on Tribological Properties of Polytetrafluoroethylene Drawn Uniaxially at Different Temperature

Summary: Wear behavior correlations with morphology have been established from polytetrafluoroethylene (PTFE) drawn at 200, 327, and 375 °C with draw ratio about 4. The friction coefficient and wear rate for PTFE drawn at 327 °C are lower and the wear rate is lower than that of undrawn PTFE by about 30%. The structures of samples were characterized by scanning electron microscope (SEM), DSC, and wide angle X‐ray diffraction (WAXD). Results indicate that the debris morphologies of samples are different. The differences in the tribological behavior of undrawn and drawn samples were attributed to the improvement of the degree of the crystalline, fibrillation, and orderliness by drawing, especially, for PTFE drawn at 327 °C. The orderliness of molecular arrangement along the drawn direction is also higher for PTFE drawn at 327 °C than those of PTFE drawn at 200 and 375 °C, respectively. Therefore, the intensity of covalent bond along drawn direction is higher. The shear resistance and the deformability of the material are greatly improved and the size of the wear breakage unit decreases, which results in a good tribological property for PTFE drawn at 327 °C.

SEM morphology of fractured surface perpendicular to the draw direction for PTFE drawn at 327 °C.     

膨胀型防火涂料的研究

介绍了膨胀型防火涂料的防火机理、组成、特点以及发展趋势。     

Different effects of tri(acryloyloxyethyl) phosphate on the thermal degradation of photopolymerized epoxy acrylate and polyurethane acrylate films

Tri(acryloyloxyethyl) phosphate (TAEP) was blended in different ratios with epoxy acrylate EB600 and polyurethane acrylate EB270 to obtain a series of UV curable flame retardant resins. The thermal degradation mechanisms of their cured films in air were studied by thermogravimetric analysis, in situ Fourier‐transform infrared spectroscopy, and direct pyrolysis/mass spectrometry measurements. The results showed that the phosphate group in TAEP first degraded to form poly(phosphoric acid) before the degradation of EB600. Then, the formed poly(phosphoric acid) effectively promoted the conversion of EB600 to form char, which prevented the sample from further burning. However, urethane group in EB270 degraded simultaneously with phosphate group in TAEP, leading to not effectively increase the conversion of EB270 to char during the thermal degradation. It was thus found that the addition of TAEP more effectively improved the thermal stability, flame retardance, and the char yield during combustion of EB600 than those of EB270. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3130–3137, 2006     

中国石化2004年乙烯生产述评

在对中国石化集团公司2004年乙烯生产运行情况进行简要回顾与分析的基础上,提出2005年工作重点及其具体措施。     

三维电极电解阴离子表面活性剂废水的研究

采用三维电极电解法对含阴离子表面活性剂（LAS）废水的处理进行了研究，考察了不同电极组合、槽电压、停留时间、电极间距及废水的pH值对降解效果的影响，并对电解机理作了初步探讨.实验表明：LAS废水处理的最佳工艺为：极间距2cm，槽压为8V，电解时间为40min.LAS、COD、TOC的去除率分别在94.5%、66.2%和58.7%以上.电极材料对去除率有很大影响.     

世玛3%OF防除春麦田禾本科杂草药效试验

田间试验结果表明，用世玛225ml/hm^2 Genapol LRO 600ml/hm^2,40d对野燕麦（Auena fatua）、多花黑麦草（Lolium multiflorum)鲜重效果分别为88.1%、94.0%。对小麦安全，与对照比增产15.3%。     

The kinetics of desorption in the presence of a gas phase of the desorbing molecule: CO/Re(001)

TPD/Exchange from CO/Re(001) in a gas ambience showed that the absolute rate of desorption depends on the gas pressure and has a first plus second order rate law. It is proposed that desorption is a two step process from the adsorbed state to a stable intermediate which is itself weakly adsorbed.