聚合物/蒙脱土纳米复合材料的研究进展

介绍了蒙脱土的结构特点，聚合物／蒙脱土复合材料的帛备方法和分类，讨论了各种聚合物／蒙脱土纳米复合材料的性能特点和应用。聚合物／层状硅酸盐蒙脱土纳米复合材料具有优异的性能，是目前材料学科研究的热点之一。     

聚合物／蒙脱土纳米复合材料的研究进展

综述了蒙脱土(MMT)的结构特征、蒙脱土的有机化改性、聚合物/蒙脱土纳米复合材料(PMN)的制备方法以及聚合物/蒙脱土纳米复合材料的结构特性及性能特点。     

聚乙烯/蒙脱土纳米复合材料的制备及性能研究

以蒙脱土／十六烷基三甲基溴化铵作为前驱物负载Ziegler-Natta催化剂，通过插层原位聚合的方法制备了聚乙烯／蒙脱土纳米复合材料。对聚乙烯／蒙脱土纳米复合材料的制备规律进行了研究。用透射电镜、扫描电镜、XRD，DSC等手段研究了结构和性能的相互关系，以及蒙脱土的含量对复合材料熔点与结晶行为的影响。研究表明：蒙脱土的片层结构被破坏，并以纳米级均匀分散在聚合物基体中。蒙脱土的质量分数为3％左右时，聚乙烯／蒙脱土纳米复合材料具有优良的综合性能。     

蒙脱土结构特性及在聚合物基纳米复合材料中的应用

对蒙脱土的晶层结构、分散性、流变性及表面修饰进行了系统的评述。蒙脱土片层含有Lewis酸点及过渡金属离子可用于烯类单体的催化聚合反应;自从丰田汽车公司使用尼龙 6／粘土纳米复合材料以来,蒙脱土(具有膨润性的粘土)在聚合物基纳米复合材料中的研究和应用正越来越受到世人的关注。对蒙脱土／聚合物纳米复合材料的制备方法及其进展也进行了综述。     

聚合物/蒙脱土纳米复合材料研究进展

文章简要介绍了蒙脱土的结构,概述了聚合物/蒙脱土纳米蒙脱土材料的结构及性能,详细介绍了聚丙烯(PP)/蒙脱土、聚乙烯(PE)/蒙脱土、环氧树脂(EP)/蒙脱土纳米复合材料国内外最新的研究进展,叙述了聚合物/蒙脱土纳米复合材料优良的力学性能和热学性能。最后对聚合物/蒙脱土纳米复合材料的未来发展做了预测。     

聚氨酯/有机蒙脱土纳米复合材料的合成与表征

采用共沸法精制有机蒙脱土，估算了有机蒙脱土中吸附水质量分数约为8．3％。结构水的质量分数约为4．1％。用两步法原位聚合制备了聚氨酯／有机蒙脱土(PU／MMT)纳米复合材料，表征了纳米复合材料的形态、动态力学性能和物理机械性能。结果表明，有机蒙脱土对聚氨酯有增强和增韧双重作用。有机蒙脱土对聚合物分子的限制作用使PU／MMT纳米复合材料的玻璃化转变温度升高，储能模量和损耗模量也有明显提高。     

插层法制备聚合物/蒙脱土纳米复合材料的研究进展

对插层法制备聚合物／蒙脱土纳米复合材料的国内外研究现状作了简要的回顾，并对聚合物／蒙脱土纳米复合材料的力学性能、结晶性能、阻隔性能、热稳定性、各向异性及阻燃性能进行了综述。     

环氧树脂/蒙脱土纳米复合材料性能的研究

用一种新型的热稳定性较好的改性剂2，2’-二[4-(4-氨基苯氧基)苯基]-丙烷(BAPP)改性钠基蒙脱土，再与环氧树脂进行纳米复合制备了环氧树脂／蒙脱土纳米复合材料。讨论了蒙脱土用量对环氧树脂／蒙脱土纳米复合材料性能的影响，并对其结构和性能进行了表征和测试。结果表明：改性使蒙脱土层间距变大，制备出的环氧树脂／蒙脱土纳米复合材料剥离结构较好，环氧树脂／蒙脱土纳米复合材料的玻璃化转变温度和动态储能模量随改性蒙脱土用量的增加呈现较好的递增趋势。     

蒙脱土改性纳米复合乳液的研究进展

纳米技术是一项前沿科学技术,目前,聚合物,蒙脱土纳米复合材料是重要的工程材料之一。由于蒙脱土具有层状硅酸盐的特殊结构,使得聚合物,蒙脱土纳米复合材料的各项性能均得到较大改善。介绍了蒙脱土的特性及其复合材料的结构,详细介绍了近年来国内外学者采用共混法和插层聚合法制备蒙脱土改性纳米复合乳液所做的研究工作。对蒙脱土改性不同乳液的应用研究现状进行了综述。指出了乳液法制备聚合物／蒙脱土纳米复合材料研究中存在的问题和应努力的方向。     

熔融插层法制备聚合物/纳米蒙脱土的研究进展

简要介绍了熔融插层法制备聚合物／纳米蒙脱土复合材料的研究进展。结合热力学和动力学的分析，概括了熔融插层法一些理论上的研究进展。总结了目前关于熔融插层法制备聚合物／纳米蒙脱土复合材料及其表征的最新研究成果。     

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     

羧甲基纤维素/蒙脱土纳米复合材料对刚果红染料的吸附及解吸性能

用X 射线衍射、透射电镜和扫描电镜对羧甲基纤维素/蒙脱土纳米复合材料的结构进行表征。采用溶液插层复合法制备纳米复合材料,探讨不同羧甲基纤维素与蒙脱土质量比、反应时间和反应温度对纳米复合材料吸附刚果红染料吸附量的影响,并初步研究了纳米复合材料的解吸性能。亚微观观察表明：羧甲基纤维素通过破坏蒙脱土的晶体结构插层进入蒙脱土层间,形成插层-剥离型纳米复合材料;当羧甲基纤维素与蒙脱土质量比为1∶1,反应时间为6 h,反应温度为60℃时,纳米复合材料对刚果红染料的吸附量最大,可达50.42 mg·g-1;当解吸试剂氢氧化钠浓度为0.01 mol·L-1时,超声波解吸50 min的纳米复合材料脱附率可达80.17%。     

环氧树脂/蒙脱土纳米复合材料制备及性能的研究进展

介绍蒙脱土(MMT)的性质及其有机化改性,详细阐述了环氧树脂(EP)/MMT纳米复合材料的制备方法及其性能,以及MMT在EP中的剥离机理,指出实现MMT在EP基体中完全剥离的方法仍是目前制备EP/MMT纳米复合材料的关键问题.     

累托石/SBR纳米复合材料的结构与性能

采用乳液共混共凝法制备累托石／SBR复合材料，研究累托石纯度对材料物理性能的影响，并与蒙脱石／SBR复合材料进行对比。结果表明，累托石／SBR属于纳米复合材料，分散相的形状系数稍高于蒙脱石体系；高纯度累托石是制备性能优异的累托石／sBR纳米复合材料的关键。两种纳米复合材料均具有良好的气密性，累托石／SBR复合材料分散相形状系数略大，气密性更优。两者均可以作为性价比适中的轮胎气密层或内胎材料。     

共聚尼龙/蒙脱土纳米复合材料的制备、结构与性能

用熔融挤出法制备了尼龙/蒙脱土纳米复合材料,并采用TEM、DSC等测试方法对所得纳米复合材料的微观结构和性能进行了研究。测试结果表明:蒙脱土在聚合物基体中分散均匀,片层厚度集中于10 nm左右,形成均匀的网状结构;并且复合材料拉伸性能有不同程度提高,流动性能降低了15.9%;蒙脱土的加入不影响聚合物的晶型,但对复合材料的结晶速率、结晶度影响较大。纳米蒙脱土片层在复合材料结晶过程中起到异质核的作用。     

Preparation and anticorrosive properties of PANI/Na-MMT and PANI/O-MMT nanocomposites

Nanocomposites of polyaniline (PANI) with organophilic montmorillonite (O-MMT) and hydrophilic montmorillonite (Na-MMT) were prepared. The nanocomposites were characterized using FT-IR, D.C. electrical conductivity measurement and cyclic voltammetry techniques. It was found that PANI/Na-MMT nanocomposite has lower (5.8%) and PANI/O-MMT nanocomposite has higher (29.4%) conductivity compared to pure polyaniline. Cyclic voltammetry experiments showed that both nanocomposites are electroactive. The anticorrosive properties of a 100 μm thickness coating of nanocomposites on iron coupons were evaluated and compared with pure polyaniline coating. According to the results PANI/MMT nanocomposites have enhanced corrosion protection effect in comparison to pure polyaniline coating. Results showed also that the PANI/Na-MMT and PANI/O-MMT nanocomposites have considerably different corrosion protection efficiencies in various corrosive environments.     

Effect of clay modification on the morphological,mechanical, and thermal properties of polyamide 6/polypropylene/montmorillonite nanocomposites

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic montmorillonite (OMMT) were prepared by melt compounding. The sodium montmorillonite (Na‐MMT) was modified using three different types of alkyl ammonium salts, namely dodecylamine, 12‐aminolauric acid, and stearylamine. The effect of clay modification on the morphological and mechanical properties of PA6/PP nanocomposites was investigated using x‐ray diffraction (XRD), transmission electron microscopy (TEM), tensile, flexural, and impact tests. The thermal properties of PA6/PP nanocomposites were characterized using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and heat distortion temperature (HDT). XRD and TEM results indicated the formation of exfoliated structure for the PA6/PP nanocomposites prepared using stearylamine modified montmorillonite. On the other hand, a mixture of intercalated and exfoliated structures was found for the PA6/PP nanocomposites prepared using 12‐aminolauric acid and dodecylamine modified montmorillonite. Incorporation of OMMT increased the stiffness but decreased the ductility and toughness of PA6/PP blend. The PA6/PP nanocomposite containing stearylamine modified montmorillonite showed the highest tensile, flexural, and thermal properties among all nanocomposites. This could be attributed to better exfoliated structure in the PA6/PP nanocomposite containing stearylamine modified montmorillonite. The storage modulus and HDT of PA6/PP blend were increased significantly with the incorporation of both Na‐MMT and OMMT. The highest value in both storage modulus and HDT was found in the PA6/PP nanocomposite containing stearylamine modified montmorillonite due to its better exfoliated structure. POLYM. COMPOS., 31:1156–1167, 2010. © 2009 Society of Plastics Engineers     

三元尼龙/蒙脱土纳米复合材料制备及表征

将自制有机蒙脱土与三元尼龙通过双螺杆挤出机熔融挤出插层复合，制得了剥落型纳米复合材料。通过透射电子显微镜、差示扫描量热分析等手段对复合材料的亚微观结构、热性能和流动性能进行了测试。结果表明，蒙脱土晶层均匀地分散于基体中，平均厚度约10nm；三元尼龙/蒙脱土纳米复合材料较三元尼龙的流动性能降低，熔点有所升高。蒙脱土的加入改善了基体的结晶性能，蒙脱土晶层起到成核剂的作用。     

环氧树脂插层纳米复合材料固化动力学研究

运用自制的有机蒙脱土，采用浇模固化成型法制备环氧树脂／二乙烯三胺／有机蒙脱土纳米复合材料，对固化产物利用XRD（X射线衍射）分析有机蒙脱土的层间距变化，确定产物为插层型的纳米复合材料，并用DSC（差示扫描量热法）跟踪环氧树脂固化行为。运用Kissinger,Flynn-Wall-Ozawa,Crane方法对环氧树脂的固化反应过程进行分析，求出活化能和反应级数等动力学以在数。结果发现，加入有机化蒙脱土后使固化反应活化能和频率下降，从而有利于固化工艺的实现，便于纳米复合材料实际应用。     

Deformation and fracture behavior of polyamide nanocomposites: The effect of clay dispersion

This study describes the effect of the clay content and its dispersion on deformation and fracture behavior of polyamide nanocomposites. Two nanocomposite systems, intercalated and exfoliated nanocomposites containing layered silicate, were compared. They were prepared by melt‐compounding of polyamide with sodium montmorillonite or organophilized montmorillonite. It has been shown that while the exfoliated structure imparts to the nanocomposite higher stiffness and strength, the toughness is inferior to the intercalated nanocomposite. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008