S，N耦合掺杂TiO2柱撑蒙脱石催化剂制备

以Na基蒙脱石为吸附剂,二氧化钛（TiO2）水解溶胶、L-半胱氨酸为双组分吸附质,采用双组分竞争吸附的方法,制备了S,N耦合掺杂TiO2柱撑蒙脱石光催化剂。探讨了蒙脱石的吸附特点,修正了Langmuir双组分竞争吸附公式,利用二元回归方法,求出了修正因子Y1=1．00011,Y2=0．99938。吸附实验表明,双组分吸附体系中,吸附质之间的相互作用不容忽视;XRD分析：表明,催化剂中TiO2全部为锐钛矿相晶体;XPS光电子能谱分析表明,S^4＋替换Ti^4＋进入TiO2晶格,S^2-、N^2-替换晶格氧而进入TiO2晶格;光催化降解实验表明,可见光照射下,催化剂有较高的光催化活性,3h内亚甲基蓝脱色率达65％左右。     

HIPS/蒙脱土复合材料炭层结构对阻燃性能的影响

采用熔融插层法制备了不同有机蒙脱土(OMMT)及无机蒙脱土(MMT)含量的HIPS/OMMT和HIPS/MMT复合材料,并通过锥形量热仪评价了复合材料的阻燃性能;采用数码相机、扫描电镜(SEM)观察了燃烧残余物结构。结果表明,OMMT的加入显著提高了HIPS/OMMT复合材料阻燃性,而MMT的加入,HIPS/MMT复合材料的阻燃性能提高不明显。HIPS/OMMT复合材料燃烧结束形成了皮层-蜂窝层复合的炭渣结构,对其阻燃性有重要的影响。     

不饱和阳离子水性聚氨酯改性蒙脱土的制备与性能研究

合成出一种不饱和水基阳离子聚氨酯树脂（UCWPU）,以其作为插层剂并采用超声波助混技术对蒙脱土（MMT）进行有机改性,通过阳离子交换制备出含有不饱和官能团的活性有机蒙脱土（OMMT）。采用傅里叶变换红外光谱（FTIR）、广角X射线衍射（XRD）、透射电镜（TEM）、热失重分析（TGA）和显微电泳法等检测手段分别对改性后蒙脱土的结构、性能进行了分析表征。结果表明,改性后的蒙脱土层间距由原来的1．21nm增大到2．13nm,阳离子聚氨酯改性的蒙脱土粒子电性显正电。FT—IR和TGA测试结果表明UCWPU分子链稳定存在于蒙脱土层问。     

Preparation and characterization of light‐cured methacrylate/montmorillonite nanocomposites

Polymer/clay nanocomposites were prepared from dimethacrylate monomers, commonly used in dental restorative resins, and an organically modified silicate (montmorillonite). The photopolymerization process was hardly affected by the presence of the silicate filler, and thus 2 mm thick samples containing 3 wt% clay were extensively cured. Transmission electron microscopy revealed that the montmorillonite platelets were either intercalated or exfoliated. Nevertheless, for all formulations, intermediate‐sized aggregates of about 1 µm were present and their fraction increased as the amount of filler increased. The presence of the clay was found to have no major effect on the flexural modulus and compressive yield strength of the nanocomposites. Moreover, the water uptake of nanocomposites containing 3 wt% clay was about 10–15% higher than that of unfilled monomers. Modification of the clay surface with alternative organic cations is certainly necessary in order to achieve an optimal dispersion of the clay in the polymer matrix. Copyright © 2010 Society of Chemical Industry     

Synthesis of poly(ε‐caprolactone)/clay nanocomposites using polyhedral oligomeric silsesquioxane surfactants as organic modifier and initiator

Poly(ε‐caprolactone)/clay nanocomposites were synthesized by in situ ring‐opening polymerization of ε‐caprolactone in the presence of montmorillonite modified by hydroxyl functionalized, quaternized polyhedral oligomeric silsesquioxane (POSS) surfactants. The octa(3‐chloropropyl) polyhedral oligomeric silsesquioxane was prepared by hydrolytic condensation of 3‐chloropropyltrimethoxysilane, which was subsequently quaternized with 2‐dimethylaminoethanol. Montmorillonite was modified with the quaternized surfactants by cation exchange reaction. Bulk polymerization of ε‐caprolactone was conducted at 110°C using stannous octoate as an initiator/catalyst. Nanocomposites were analyzed by X‐ray diffraction, transmission electron microscopy, thermo gravimetric analysis, and differential scanning calorimetry. Hydroxyl functionalized POSS was employed as a surface modifier for clay which gives stable clay separation for its 3‐D structure and also facilitates the miscibility of polymer with clay in the nanocomposites due to the star architecture. An improvement in the thermal stability of PCL was observed even at 1 wt % of clay loading. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Polyolefin‐based nanocomposite: The effects of processing aids

PP/organoclay nanocomposites were prepared using different processing aids (EMCA and PPG), and their effects on the thermal and mechanical properties were evaluated by WAXD, TEM, SEM, DSC, and mechanical tests. This study helps to clarify the effects of processing aids on the organoclay surface and on the intercalation and exfoliation processes. Nanocomposites with elongated intercalated and partially exfoliated structures were obtained, mainly when C‐15A was used. The results for the mechanical properties showed that the processing aids increased the impact strength significantly (up to three times that of neat PP) but reduced the flexural modulus of PP nanocomposites. PPG, which is polar promoted wetting MMT surface, thus increasing its interlayer distance, mainly for PP/C‐20A nanocomposites. However, it reduced the interfacial adhesion between the clay and the matrix. Nanocomposites impact strength was improved, especially when the C‐15A organoclay was used, while were achieved better results with the C‐20A organoclay when EMCA was used. The larger the amount of processing aid added, the higher the impact strength, but the lower the flexural modulus of the nanocomposites. PPG caused debonding of the clay particles and increased the number of microvoids, generating more mechanisms to aid in the energy dissipation of the systems. EMCA promoted debonding of clay particles with the formation of fibrils, indicating stronger interactions between the clay and matrix. A slight nucleation effect for PP crystallization was observed, mainly when EMCA was used. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

铁盐改性蒙脱土活化过一硫酸盐去除水中双酚A效能与机理

有机微污染物是饮用水处理的新兴难题,过一硫酸盐氧化是去除有机微污染物的有效途径,但存在催化剂成本高、制备和再生过程复杂等问题。本文尝试利用三价铁盐改性后的蒙脱土（Fe-MMT）作为过一硫酸盐催化剂,研究Fe-MMT活化过一硫酸盐（PMS）降解饮用水中双酚A的规律和效能。实验结果表明:双酚A能够快速吸附到Fe-MMT表面,并在1 h内的去除率高达96.4%。分析认为,Fe-MMT的纳米级层间距加速了Fe³⁺与PMS间的电子转移,有利于PMS活化分解产生HO·和SO₄·^-自由基,导致水中双酚A快速降解。此外,Fe-MMT的层状结构能够有效抑制水中背景腐殖酸成分对PMS活化的影响。铁盐改性蒙脱土的制备和再生过程简单,可作为过一硫酸盐催化剂应用于饮用水处理领域。     

蒙脱土负载型固体酸催化剂的烷基化性能与结构研究

以酸化后蒙脱土为载体，采用浸渍蒸发法制备了环境友好的蒙脱土负载znCl2型固体酸催化剂。研究了蒙脱土酸化处理、ZnCl2负载量及活化温度对催化剂烷基化活性的影响，并初步考察了催化剂的稳定性，比较了几种不同酸催化剂的烷基化活性。利用XRD、BET、TG—DTA、吡啶吸附FTIR对催化剂的结构进行了表征和测定；结果表明，蒙脱土酸化处理后形成的孔道有利于负载ZnCl2，ZnCl2与蒙脱土的羟基之间存在着化学键合，经活化后转化成Zn(0H)C1。蒙脱土负载ZnCl2后明显地提高蒙脱土表面的总酸量，催化剂活性与其表面总酸量之间有关，催化剂表面L酸与B酸的共存有利于其烷基化活性的提高。实验条件下，蒙脱土负载ZnCl2型催化剂在苯与氯节的烷基化反应中表现出较高的催化活性，二苯甲烷的收率最高可达83．6％。与其它Lewis酸试剂及酸化蒙脱土相比，蒙脱土负载型催化剂催化活性大有提高。     

聚丙烯/BA原位聚合改性MMT纳米复合材料的微观结构

通过原位聚合制备了聚丙烯酸丁酯（PBA）改性蒙脱土（MMT），再与PP熔融复合，制成PP／MMT复合材料，利用X射线衍射（XRD）、扫描电子显微镜（SEM）和电子探直表征了复合材料的微观结构。结果表明：PP／MMT复合材料为纳米复合材料，MMT的加入诱导了β－晶型PP的形成。     

聚丙烯/BA原位聚合改性MMT纳米复合材料的DSC分析与力学性能

通过原位聚合制备了聚丙烯酸丁酯 (PBA )改性蒙脱土 (MMT ) ,与聚丙烯 (PP)熔融复合制成PP/MMT纳米复合材料 ,系统地研究了复合材料的熔融、结晶行为和力学性能。结果表明 :随着处理MMT的BA用量的增加 ,PP/MMT纳米复合材料中PP相的结晶度、熔点和结晶温度明显提高 ,结晶速度加快 ;复合材料的拉伸强度变化不大 ,但拉伸模量和冲击强度有显著提高。当BA/OMMT质量比为 1/ 12左右时 ,复合材料的韧性趋于平衡值 ,而拉伸模量出现最大值