聚乙烯/粘土纳米复合材料燃烧性能研究

使用锥形量热计、热重分析仪对聚乙烯(PE)／粘土纳米复合材料的燃烧性能进行了研究。结果表明，有机改性纳米粘土对PE燃烧性能有较大影响，随眷纳米粘土合量的增加，PE的热分解速率和最大热释放速率都明显下降，这对材料应用中的火灾安全性具有重要意义。     

牙舟泥哨

牙舟泥哨作为民间陶制玩具在数百年的发展中逐渐形成了自己的风格和个性，在造型、审美上带有独特黔南地方特色。本文从造型和审美的角度对牙舟泥哨进行了分析。     

Rheology of poly(propylene)/clay nanocomposites

The linear and nonlinear shear rheological behaviors of poly(propylene) (PP)/clay (organophilic‐montmorillonite) nanocomposites (PP/org‐MMT) were investigated by an ARES rheometer. The materials were prepared by melt intercalation with maleic anhydride functionalized PP as a compatibilizer. The storage moduli (G′), loss moduli (G″), and dynamic viscosities of polymer/clay nanocomposites (PPCNs) increase monotonically with org‐MMT content. The presence of org‐MMT leads to pseudo‐solid‐like behaviors and slower relaxation behaviors of PPCN melts. For all samples, the dependence of G′ and G″ on ω shows nonterminal behaviors. At lower frequency, the steady shear viscosities of PPCNs increase with org‐MMT content. However, the PPCN melts show a greater shear thinning tendency than pure PP melt because of the preferential orientation of the MMT layers. Therefore, PPCNs have higher moduli but better processibility compared with pure PP.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2427–2434,2004     

Thermal and surface characterization of polyurethane–urea clay nanocomposite coatings

This paper reports synthesis and characterization of polyurethane–urea (PU‐urea) and the nanocomposites derived from the PU‐urea with silicate clays. Organophilic montmorillonite cotreated by cetyl trimethyl ammonium bromide (CTAB) was synthesized and used to prepare PU‐urea/montmorillonite nanocomposites coatings. PU‐ureas were prepared from polyethylene glycol (PEG), polypropylene glycol (PPG), trimethylol propane (TMP), and 4,4′‐diphenylmethane diisocyanate (MDI) by reacting excess diisocyanate with polyether glycols. The excess isocyanate of the prepolymers was cured with atmospheric moisture. The synthesized moisture cured PU‐urea and nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetric (DSC), and angle resolved X‐ray photoelectron spectroscopy (AR‐XPS). The thermal stability of the PU‐urea nanocomposites was higher relative to the mother PU‐urea films. DSC results showed a slight enhancement in the soft segment glass transition temperature after 3 wt % clay loading. The surface properties showed an enrichment of the soft segment toward the surface. An enhancement in the hard segment composition in the nanocomposite coatings has resulted in enhancing the phase mixing process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2393–2401, 2006     

Films formed from polystyrene latex/clay composites: A fluorescence study

This study reports a steady-state fluorescence (SSF) technique for studying film formation from surfactant-free polystyrene (PS) latex and Na-montmorillonite (SNaM) composites. The composite films were prepared from pyrene (P)-labeled PS particles and SNaM clay at room temperature and annealed at elevated temperatures in 10-min intervals above glass transition temperature (t₃) of polystyrene. During the annealing processes, the transparency of the film improved considerably. Scattered light (I_s) and fluorescence intensity (I_p) from P were measured after each annealing step to monitor the stages of film formation. Evolution of transparency of composite films was monitored by using photon transmission intensity, I_tr. Scanning electron microscopy (SEM) was used to detect the variation in physical structure of annealed composite films. Minimum film formation temperature, T_q, and healing temperatures, T_h, were determined. Void closure and interdiffusion stages were modeled and related activation energies were determined. It was observed that both activation energies increased as the percent of SNaM was increased in composite films.     

Studies on the poly(styrene‐b‐butadiene‐b‐styrene)/clay nanocomposites prepared by melt intercalation

Two types of SBS/OMMT composites are prepared by melt blending using a twin‐screw extruder. An X‐ray diffractometer indicates that polymer chains have intercalated into the gallery of the clay. It is shown in TEM photos that the thickness of the layer aggregate in the SBS1301 matrix is approximately 200 Å, but in the SBS4402 matrix the size of the filler particle is in micrometers. When SBS1301 is intermingled into SBS4402/OMMT, the particle size is reduced obviously. The tensile strength and elongation at break of the nanocomposite, SBS1301/OMMT, increase with the addition of OMMT; and when addition is 5phr, they achieve maximum. A small content of OMMT (less than 5phr) can prevent the deterioration of the mechanical properties of the SBS1301/MMT. In addition, a small content of SBS4402 (less than 20 wt %) can improve the mechanical properties of the SBS1301/OMMT composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 146–152, 2005     

成都粘土预处理垃圾渗滤液中COD的实验研究

在不同实验条件下,以成都长安垃圾填埋场渗滤液为研究对象,利用成都粘土去除垃圾渗滤液中的COD.研究表明,成都粘土对垃圾渗滤液中的COD具有一定的去除效果.在最佳实验条件为用土量85g/L,pH=6.0,搅拌速度150 r/m in,搅拌时间40m in,静止时间12h时,成都粘土对垃圾渗滤液中COD的去除率可达到30%.     

Evaluation of group effect of pile group under dragload embedded in clay

A simple semi-empirical analysis method for predicting the group effect of pile group under dragload embedded in clay was described assuming an effective influence area around various locations of pile group. Various pile and soil parameters such as the array of pile group, spacing of the piles (S), embedment length to diameter ratio of piles (L/D) and the soil properties such as density (γ), angle of internal friction (φ) and pile-soil interface friction coefficient (μ) were considered in the analysis. Model test for dragload of pile group on viscosity soil layer under surface load consolidation conditions was studied. The variations of dragload of pile, resistance of pile tip and the layered settlement of soil with consolidation time were measured. In order to perform comparative analysis, single pile was tested in the same conditions. The predicted group effect values of pile group under dragload were then compared with model test results carried out as a part of the present investigation and also with the values reported in literatures. The predicted values were found to be in good agreement with the measured values, validating the developed analysis method. The model test results show that negative skin friction of pile shaft will reach 80%–90% of its maximum value, when pile-soil relative displacement reaches 2 mm. Foundation item: Project(50679015) supported by the National Natural Science Foundation of China     

CaO—SiO2-FeO—Cl体系中Zn、Pb挥发物的热力学研究

应用FaetSage热力学软件对不同温度下的FeO—CaO—SiO2-Cl体系中Zn、Ph挥发行为进行分析,采用气流携带法对FeO—CaO-SiO2-Cl体系中Zn、Pb挥发物的饱和蒸气压进行测定,并通过试验分析了温度对其体系中Zn、Pb挥发率的影响。结果表明,温度为970～1030K条件下FeO-CaO-SiO2-Cl体系中Zn、Pb主要以氯化物形式存在,氯化物的饱和蒸气压均随着温度的升高而增加,且InP～1／T呈较好的线性关系,其体系中Zn、Pb挥发率亦随着温度的升高而增加。     

FeO-CaO-SiO2-Al2O3-ZnO—PbO-Cl体系中Zn、Pb氯化物饱和蒸气压的测定

采用气流携带法对FeO-CaO-SiO2-Al2O3-ZnO-PbO-Cl体系中Zn、Pb氯化物的饱和蒸气压进行测定,并对温度、渣成分、Cl含量等影响因素进行了分析。结果表明,温度为970～1030K条件下FeO-CaO-SiO2-Al2O3-ZnO-PbO-Cl体系中Zn、Pb氯化物饱和蒸气压均随着温度的升高而增加,且P1）氯化物蒸气压值的对数与温度的倒数之间呈较好的线性关系。碱度、FeO含量均对Zn、Pb氯化物的饱和蒸气压影响很大,低碱度可提高Zn、Pb氯化物的饱和蒸气压,高FeO含量虽可增加ZnCl2饱和蒸气压,却降低了Pb氯化物的饱和蒸气压。Cl含量越高,该体系中Zn、Pb氯化物的饱和蒸气压越大。