聚乙烯醇/蒙脱石纳米复合材料的制备工艺研究

通过正交实验法研究了溶液插层-流延成膜法制备聚乙烯醇/蒙脱石纳米复合材料中制备工艺条件对复合材料结构的影响,确定了最佳的制备方法。对复合材料进行了TEM表征,结果表明:蒙脱石片层均匀的剥离分散在PVA基体中,蒙脱石含量不高于7.5wt%时,形成了剥离型的纳米复合材料;高于10wt%时,形成了剥离型和插层型共存的纳米复合结构。     

聚合物/蒙脱石纳米复合材料制备与性能

简要介绍了蒙脱石晶体结构及聚合物/蒙脱石纳米复合材料形成机理 ,重点综述了纳米复合材料的制备方法、性能、发展方向和应用前景。     

聚合物／蒙脱石纳米复合材料的制备及研究现状

文章介绍了蒙脱石的研究前沿——聚合物／蒙脱石纳米复合材料的制备方法、插层剂的选择及其性能。在此基础上对其研究现状进行了概括，这对于充分利用膨润土资源具有重要意义。     

聚合物/蒙脱石纳米复合材料研究进展

综述了蒙脱石的结构以及聚合物/蒙脱石纳米复合材料的制备原理与方法,重点介绍了纳米复合材料的制备方法与应用前景.     

表面活性剂在聚合物/蒙脱石纳米复合材料制备中的应用

简要叙述了蒙脱石的结构;综述了阳离子表面活性剂插层蒙脱石以形成有机蒙脱石的机理、插层方法以及阳离子表面活性剂的结构对被插层蒙脱石的层间距的影响;讨论了不同类型的聚合物/蒙脱石纳米复合材料制备方法;同时比较了所得到的纳米复合材料的力学性能、热性能与纯聚合物的力学性能和热性能。结果表明:前者的力学性能和热性能比后者均有较大程度的提高。最后提出了聚合物/蒙脱石纳米复合材料目前存在的问题、发展方向和应用前景等。     

钛交联蒙脱石纳米复合材料制备及应用进展

钛交联蒙脱石具有多孔、高比表面、大的层间距等特性,成为近几年来纳米多孔材料研究的热点之一。作者综述了钛交联蒙脱石纳米复合材料的交联机理、制备、及其在光催化降解有机物、NOx的选择还原和有机污染物的吸附等的应用研究进展。     

聚乙烯醇/蒙脱石纳米复合材料的制备与表征

以钠质蒙脱石和聚乙烯醇为原料,通过溶液插层-流延成膜法制备不同蒙脱石质量分数的聚乙烯醇/蒙脱石纳米复合材料薄膜。用X射线衍射(XRD)、扫描电子显微镜(SEM )和热重分析(TGA)对复合材料的结构进行了表征。结果表明,聚乙烯醇分子成功进入蒙脱石的层间,实现了在纳米尺度上的复合;蒙脱石质量分数高于7 5%形成插层型的纳米复合材料,低于7 .5%的形成剥离型的纳米复合材料;纳米复合材料的热稳定性比纯聚乙烯醇有较大提高。     

有机蒙脱石增强环氧树脂纳米复合材料的研究

介绍以有机蒙脱石作为增强组分的环氧树脂纳米复合材料的制备及其性能表征。结果表明,十六胺处理的蒙脱石层离以1－100nm尺度分散于环氧树脂基体中,复合材料的物性得到提高,当蒙脱石含量比在3％时,马丁耐热提高9℃,冲击强度提高了122％,但进一步增加蒙脱石的含量比,上述两性能不升反降。     

聚乙烯醇/蒙脱石纳米复合材料的结构与性能

通过溶液插层 流延成膜法,以聚乙烯醇和钠质蒙脱石为原料,制备出了不同蒙脱石含量的聚乙烯醇/蒙脱石纳米复合材料薄膜。用X射线衍射(XRD)、扫描电子显微镜(SEM)、热重分析(TGA)和力学性能测试对复合材料的结构和性能进行了表征。结果表明,聚乙烯醇分子成功进入蒙脱石的层间,实现了在纳米尺度上的复合;蒙脱石含量高于7 5wt%形成插层型的纳米复合材料,低于7 5wt%形成剥离型的纳米复合材料;在SEM图片上还观察到了纳米复合材料的微观结构。纳米复合材料的热稳定性、拉伸强度和直角撕裂强度均比纯聚乙烯醇有很大提高。     

聚丙烯/蒙脱石阻燃纳米复合材料的研究

阐述了纳米复合材料阻燃性研究的进展,介绍了其制备方法、微观结构的表征手段(XRD)及阻燃性测试技术(锥形量热仪,TGA,氧指数仪),讨论了其燃烧特性和阻燃机理.指出了这种阻燃方法目前存在的问题,展望了该阻燃材料开发应用前景.     

聚苯乙烯-丙烯腈/蒙脱土纳米复合材料的制备和结构

引 言 近年来,聚合物/蒙脱土纳米复合材料已成为材料科学界的一个研究热点,各种高分子材料均被尝试用来制备此类纳米复合材料以提高聚合物的力学性能、热性能和阻隔性能[1-4].对聚合物/蒙脱土纳米复合材料的研究主要集中在制备方法、结构和性能表征方面,如何利用蒙脱土片层的特性来探索简单易行、成本较低且能够使蒙脱土充分剥离分散的方法一直是此方面的研究焦点.     

聚丙烯/蒙脱土纳米复合材料研究

本文综述了聚丙烯／蒙脱土纳米复合材料的特点、制备方法,并对复合材料的结构表征方法作了介绍。     

Superabsorbent polymeric materials. XII. Effect of montmorillonite on water absorbency for poly(sodium acrylate) and montmorillonite nanocomposite superabsorbents

A series of novel xerogels based on sodium acrylate (NaA), montmorillonite (MMT), and N,N′‐methylene‐bisacrylamide (NMBA) were prepared by inverse suspension polymerization and water solution polymerization. The influences of pure MMT, intercalated MMT, the method of polymerization, and the content of the MMT in the copolymeric gels on the water absorbency and the initial absorption rate in deionized water and various salt solutions were investigated. Results showed that the water absorbency was increased by adding a small amount of the pure MMT into the copolymeric gels, but decreased by adding intercalated MMT into the gels. In addition, the water absorbency of the gels prepared by water solution polymerization was lower than that prepared by inverse suspension polymerization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3422–3429, 2004     

Preparation and rheological characterization of intercalated polystyrene/organophilic montmorillonite nanocomposite

Polystyrene (PS)/organophilic montmorillonite (OMMT) clay nanocomposites were prepared by a solvent casting method using chloroform as a cosolvent. Intercalation of the OMMT in the PS matrix was achieved as revealed by X‐ray diffraction. The IR spectra of the products indicated that the OMMT is homogeneously dispersed in the PS matrix. A thermogravimetric analysis (TGA) showed that the onset temperature increases linearly with the clay content. The glass‐transition temperature of the PS, examined using differential scanning calorimetry, had a trend similar to that from the TGA. The rheological properties of the PS/OMMT nanocomposites were also investigated via a rotational rheometer with a parallel plate geometry, and they exhibited sharper shear thinning and increased storage and loss modulus with clay content. Furthermore, the shear viscosity obtained from the steady shear experiment was well correlated with the complex viscosity obtained from the oscillatory experiment via the Cox and Merz relation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2106–2112, 2003     

Gelatin/montmorillonite hybrid nanocomposite. I. Preparation and properties

Gelatin/montmorillonite (MMT) hybrid nanocomposite was directly prepared with unmodified MMT and gelatin aqueous solution. Thermal and mechanical properties of the composite were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile tests. The results indicated that an intercalated or partially exfoliated nanocomposite could be achieved, and the properties of the composite were significantly improved. A T_g peak of high temperature disappeared in the DSC curve of the composite, and the thermogravity and thermally decomposed rate decreased obviously. The tensile strength and Young's modulus were also improved notably, which varied with MMT content, as well as the pH of gelatin matrix. Meanwhile, SEM photographs showed a plasticizing trend of gelatin fracture surface due to intercalation with MMT. Furthermore, the wet mechanical behavior was initially studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1189–1194, 2002     

Nonisothermal crystallization kinetics of polyoxymethylene/montmorillonite nanocomposite

The nonisothermal crystallization kinetics of polyoxymethylene (POM), polyoxymethylene/Na–montmorillonite (POM/Na–MMT), and polyoxymethylene/organic–montmorillonite (POM/organ–MMT) nanocomposites were investigated by differential scanning calorimetry at various cooling rates. The Avrami analysis modified by Jeziorny and a method developed by Mo were employed to describe the nonisothermal crystallization process of POM/Na–MMT and POM/organ–MMT nanocomposites. The difference in the values of the exponent n between POM and POM/montmorillonite nanocomposites suggests that the nonisothermal crystallization of POM/Na–MMT and POM/organ–MMT nanocomposites corresponds to a tridimensional growth with heterogeneous nucleation. The values of half‐time and the parameter Z_c, which characterizes the kinetics of nonisothermal crystallization, show that the crystallization rate of either POM/Na–MMT or POM/organ–MMT nanocomposite is faster than that of virgin POM at a given cooling rate. The activation energies were evaluated by the Kissinger method and were 387.0, 330.3, and 328.6 kJ/mol for the nonisothermal crystallization of POM, POM/Na–MMT nanocomposite, and POM/organ–MMT nanocomposite, respectively. POM/montmorillonite nanocomposite can be as easily fabricated as the original polyoxymethylene, considering that the addition of montmorillonite, either Na–montmorillonite or organ–montmorillonite, may accelerate the overall nonisothermal crystallization process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2281–2289, 2001     

三聚氰胺-甲醛树脂／蒙脱土纳米复合材料的研制

采用微波加热离子交换树脂交换法将天然钙蒙脱土转变为镍基蒙脱土。三聚氰胺单体与镍基蒙脱土层间镍离子的络合后,加入甲醛经插层原位聚合制备三聚氰胺-甲醛树脂/蒙脱土纳米复合材料。X射线粉末衍射结果显示,三聚氰胺-甲醛树脂/蒙脱土复合物试样的d_(001)值由1．41nm增至1．84nm,说明蒙脱土的硅酸盐片层被撑开。粘接剪切强度测试结果表明,蒙脱土的加入提高材料的粘接性能。     

Preparation and properties of poly(vinyl alcohol)-clay nanocomposite materials

A series of polymer-clay nanocomposite (PCN) materials that consist of poly(vinyl alcohol) (PVA) and layered montmorillonite (MMT) clay are prepared by effectively dispersing the inorganic nanolayers of MMT clay in organic PVA matrix via an in situ free radical polymerization with AIBN as initiator. Organic vinyl acetate monomers are first intercalated into the interlayer regions of organophilic clay hosts and followed by a one-step free radical polymerization. The prepared poly(vinyl acetate)-clay (PVAc-clay) solution are then saponified via direct-hydrolysis with NaOH solution to form PVA-clay nanocomposite materials. The as-synthesized PCN materials are typically characterized by Fourier-Transformation infrared (FTIR) spectroscopy, wide-angle X-ray diffraction and transmission electron microscopy.The molecular weights of poly(vinyl alcohol) (PVA) extracted from polymer-clay nanocomposite (PCN) materials and bulk PVA are determined by gel permeation chromatography (GPC) analysis with THF as eluant. The viscosity property of PCN materials with different feeding amount of MMT clay is studied by an ubbelohode capillary viscometer. The morphological image of as-synthesized materials is studied by scanning electron microscopy (SEM) and optical polarizing microscope (OPM). Effects of the material composition on the thermal stability, mechanical strength, optical clarity of PVA along with a series of PCN materials, in the form of fine powder and free-standing film, are also studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analyzer (DMA) and UV-visible transmission spectra, respectively.     

Preparation and characterization of ethylene vinyl acetate copolymer/montmorillonite nanocomposite

Ethylene vinyl acetate copolymer (EVA) and monmorillonite (MMT) nanocomposites have been investigated as a function of vinyl acetate content and molecular weight of EVA and types of substituted alkyl ammonium of MMT. It is found that vinyl acetate content and type of substituted alkyl ammonium are important factors for the intercalation behaviour of MMT in MMT/EVA nanocomposite. Maleic anhydride grafted high‐density polyethylene was used as a compatibilizer to improve the intercalation behaviour of MMT. X‐ray diffraction and transmission electron microscopy were used to characterize the intercalation/exfoliation behaviour, and mechanical properties were measured. © 2003 Society of Chemical Industry     

尼龙6/蒙脱土纳米复合材料的合成新方法

利用微波加热交换法分两步将浮选后的天然钠基蒙脱土转变为镍基蒙脱土,通过配位理论把单体引入镍基蒙脱土层间,制得尼龙6/蒙脱土纳米复合材料。为制备尼龙6/蒙脱土纳米复合材料提供了一种新方法。