PUR/OMMT纳米复合材料的制备及性能研究

采用预聚法和原位插层聚合两种方法制备出了聚氨酯(PUR)/有机蒙脱土(OMMT)纳米复合材料,考察了复合材料的力学性能、热稳定性和阻燃性能。结果表明,两种方法制备的复合材料的硬度、拉伸与撕裂强度、断裂伸长率均高于纯PUR。与纯PUR相比,原位插层聚合法制备的复合材料的热分解温度提高了20℃,氧指数提高了23.5%;预聚体法制备的复合材料的分解温度提高了15℃,氧指数提高了13.5%。对比可知,原位插层聚合法制备的复合材料的热稳定性和阻燃性能明显提高,韧性得到增强。     

聚合物/纳米黏土复合材料的研究进展

简述了纳米黏土的结构特点,常见的有机化改性方法,介绍了可插层黏土的有机单体和聚合物类型。综述了聚合物/纳米黏土复合材料的制备方法,介绍了单体溶液插层、聚合物水溶液插层、乳液插层等溶液插层方法和单体熔融插层、聚合物熔融插层、熔融挤出插层等熔融插层方法。总结了聚合物/纳米黏土复合材料的国内外研究进展与应用现状,主要在汽车工业、包装材料、环境友好材料、新型工程材料等领域得到了广泛应用。     

配位插层法制备三聚氰胺-甲醛树脂/Cu2+ -蒙脱石纳米复合材料

采用微波加热溶液交换法分两步将提纯后的天然膨润土转变为Cu2 -膨润土(铜基土),通过三聚氰胺单体与Cu2 -蒙脱石层间Cu2 的配位作用,把三聚氰胺单体引入蒙脱石层间,然后加入甲醛经插层原位聚合制备三聚氰胺-甲醛树脂/Cu2 -蒙脱石纳米复合材料。X-射线衍射结果表明蒙脱石的层间距由1.25 nm增加到1.58 nm,所得产物为三聚氰胺-甲醛树脂/Cu2 -蒙脱石插层型纳米复合材料。     

SBS/蒙脱土复合材料的制备及其性能Ⅱ.复合材料的性能

分别采用大分子溶液插层法和大分子熔融插层法制备了苯乙烯-丁二烯-苯乙烯共聚物（SBS）／蒙脱土纳米复合材料．研究了材料的力学性能。纳米结构的形成对复合材料的性能产生显著影响,少量蒙脱士的引入可以明显改善SBS／蒙脱土复合材料的力学性能。无论溶液插层法制备的星型SBS／蒙脱土纳米复合材料,还是熔融插层法制备的线型SBS／蒙脱土纳米复合材料,其拉伸强度和断裂伸长率都同时增加。其中,溶液插层法制备的纳米复合材料的拉伸强度和断裂伸长率分别较纯SBS增加了75％和55％;熔融法制备的纳米复合材料的托伸强度和断裂伸长率分别较纯SBS增加了70％和18％。     

固相法制备有机黏土改性聚丙烯

采用固相法对黏土进行有机化插层改性,制备出有机黏土;通过熔融插层法制备聚丙烯/有机黏土纳米复合材料。X射线衍射分析表明,固相法改性黏土可以与聚丙烯形成纳米复合材料。利用DSC研究了纳米复合材料的结晶和熔融过程,结果表明:聚丙烯/有机黏土纳米复合材料的结晶温度提高,熔融过程、熔点及结晶度没有明显变化。力学性能测试结果表明:有机黏土含量在3%～5%范围内,纳米复合材料的力学性能最佳。     

插层法制备环氧树脂/膨润土纳米复合材料的研究现状

介绍了膨润土的结构特性、有机膨润土的制备，并对环氧树脂／膨润土纳米复合材料的制备方法及影响插层的因素进行了综述。     

有机插层剂对聚酰胺6／MMT纳米复合材料制备的影响研究

以烷基胺、季铵盐和氨基酸作为有机插层剂与蒙脱土片层进行阳离子交换，制备出层间距不同的有机蒙脱土。采用熔融插层法和原位聚合法分别制备聚酰胺（R％）／蒙脱土（MMT）纳米复合材料，并利用XRD、FT-IR、TEM对有机蒙脱土及纳米复合材料进行结构表征。研究结果表明：用烷基胺、季铵盐和氨基酸有机插层剂改性的蒙脱土层间距由原来的1．25nm分别增大到3．21nm、3．99nm和1．82m；季铵盐有机插层剂更适用于熔融插层法制备PA6／MMT纳米复合材料，而氨基酸有机插层剂更适用于原位聚合法制备PA6／MMT纳米复合材料。     

SBS/蒙脱土复合材料的制备及其性能Ⅰ.复合材料的结构

分别采用大分子溶液插层法和大分子熔融插层法制备了苯乙烯-丁二烯-苯乙烯共聚物(SBS),蒙脱土纳米复合材料,采用X射线衍射和透射电子显微镜对材料的结构进行了表征。结果表明,无论是采用大分子溶液插层法还是大分子熔融插层法,都能得到SBS／蒙脱土纳米复合材料。对于溶液插层法,蒙脱土插层剂的种类、SBS牌号对插层效果都有影响：对于熔融插层法,SBS牌号对是否形成插层型纳米复合材料影响最大,淬火对熔融挤出后得到的纳米复合材料无益。星形结构的SBS适宜于采用溶液插层法、线形结构的SBS适宜于采用熔融插层法制备纳米复合材料。     

丁基橡胶/有机黏土纳米复合材料的结构和性能

采用溶液插层法制备了丁基橡胶／有机黏土纳米复合材料,并用透射电子显微镜和X射线衍射仪研究了该纳米复合材料的形态结构。结果表明,丁基橡胶／有机黏土纳米复合材料是插层型的纳米复合材料。与丁基橡胶相比,该纳米复合材料具有优异的力学性能和气体阻隔性能,并且这2种性能均随有机黏土用量的增加而增强。填料的形状会对该纳米复合材料的气体阻隔性能产生影响。     

熔融插层法制备聚合物/蒙脱土纳米复合材料

综述了熔融插层法制备聚合物,蒙脱土纳米复合材料的新进展。熔融插层法制备聚合物,蒙脱土纳米复合材料具有设备简单、无单体限制和不需要溶剂的优点,并从热力学角度探讨了熔融插层法制备聚合物,蒙脱土纳米复合材料的不足以及改进措施。     

在超临界CO2中制备生物可降解PEC/OMMT纳米复合材料

将聚碳酸亚乙酯(PEC)与有机蒙脱土(OMMT)在超临界CO2(sc-CO2)中溶胀并混合,制备了生物可降解PEC/OMMT纳米复合材料。采用X射线衍射仪、热失重分析仪、差示扫描量热仪及万能电子拉力机等对PEC/OM-MT纳米复合材料的性能进行表征和分析。结果表明,70℃下制备的PEC/OMMT复合材料为插层型纳米复合材料;该复合材料的热稳定性和玻璃化转变温度都得到较大改善;加入少量OMMT,复合材料的拉伸性能得到明显提高。与熔融插层法和溶液插层法相比,sc-CO2法既可以解决PEC在熔融插层中面临的热降解问题,也可以避免溶液插层中使用大量有机溶剂造成的污染问题,是制备PEC/OMMT纳米复合材料的一种新方法。     

Effects of different preparation methods on the properties of poly[ethylene‐co‐(vinyl acetate)]/(Standard Malaysian natural rubber)/organoclay nanocomposites

Poly[ethylene‐co‐(vinyl acetate)] (EVA)/(Standard Malaysian natural rubber) (SMR L)/organoclay nanocomposites were prepared by using melt intercalation and solution blending methods. In both preparation methods, the EVA: (SMR L) ratio was prefixed at 50:50, while the organoclay loading was varied from 0 to 10 phr. The effects of two different processing routes and organoclay loading on the morphology, tensile, properties thermal properties, and flammability of the nanocomposites were studied. X‐ray diffraction results and transmission electron microscopy images proved that solution blending promotes better dispersion of organoclay than melt intercalation. Thus, the nanocomposites prepared by the solution‐blending method exhibited higher values of tensile strength, stress at 100% elongation (M100), and thermal stability. The M100 value and thermal stability improved proportionally with the increase of organoclay content, owing to the demobilizing effect and the barrier properties of the organoclay. The optimum tensile strength value was achieved at a 2‐phr organoclay loading. Further increases in loading decreased the strength of the nanocomposites. Tensile fracture surfaces of the nanocomposites prepared by both methods showed different fracture behavior, as evidenced by scanning electron microscopy images. Flammability decreased when the organoclay loading increased for the nanocomposites prepared by both methods. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

Synthesis and characterization of poly(ethylene terephthalate) nanocomposites with organoclay

Poly(ethylene terephthalate) (PET)/montmorillonite (MMT) nanocomposites were prepared by solution intercalation method. The clay was organo‐modified with the intercalation agent cetylpyridinium chloride (CPC). Wide‐angle X‐ray diffraction (XRD) showed that the layers of MMT were intercalated by CPC. Four nanocomposites with organoclay contents of 1, 5, 10, and 15 wt % were prepared by solution blending. XRD showed that the interlayer spacing of organoclay in the nanocomposites depends on the amount of organoclay present. According to the results of differential scanning calorimetry (DSC) analysis, clay behaves as a nucleating agent and enhances the crystallization rate of PET. The maximum enhancement of crystallization rate for the nanocomposites was observed in those containing about 10 wt % organoclay within the studied range of 1–15 wt %. From thermogravimetric analysis (TGA), we found that the thermal stability of the nanocomposites was enhanced by the addition of 1–15 wt % organoclay. These nanocomposites showed high levels of dispersion without agglomeration of particles at low organoclay content (5 wt %). An agglomerated structure did form in the PET matrix at 15 wt % organoclay. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 140–145, 2004     

Characteristics of polyvinylpyrrolidone-layered silicate nanocomposites prepared by attrition ball milling

Polyvinylpyrrolidone (PVP)/sodium montmorillonite (MMT) nanocomposites prepared via the solution intercalation method were investigated by UV/vis, SEM, X-ray diffraction, TEM, FT-IR and PLM (polarized light microscopy). PVP/MMT nanocomposites show exfoliation below 20 wt% MMT and intercalation above this concentration. Nanocomposites retain good optical clarity and increased thermal resistance with MMT content. The compatibility between PVP and MMT and their enhanced properties may be explained by hydrogen bonding interactions. In addition, the nanocomposites prepared under more rigorous mixing conditions show better transparency because the smaller particle sizes are induced. In addition, the study on optically clear PVP/MMT suspensions helps one to understand how optical anisotropy of MMT is affected by the existence of polymer in aqueous solution.     

嵌入法制备聚合物/层状硅酸盐纳米复合材料的研究进展

本文介绍和对比了嵌入法制备聚合物／层状硅酸盐纳米复合材料的三种类型,与溶液嵌入法（包括单体嵌入聚合法和聚合物溶液嵌入法）相比,熔融嵌入法具有更广泛的适用性。并从热力学和动力学角度出发,分析了影响嵌入过程的各种因素。     

Polyaniline/Montmorillonite Nanocomposites Obtained by In Situ Intercalation and Oxidative Polymerization in Cationic Modified-Clay (Sodium, Copper and Iron)

Polyaniline/montmorillonite nanocomposites (PANI/M) were obtained by intercalation of aniline monomer into M modified with different cations and subsequent oxidative polymerization of the aniline. The modified-clay was prepared by ion exchange of sodium, copper and iron cations in the clay (Na–M, Cu–M and Fe–M respectively). Infrared spectroscopy confirms the electrostatic interaction between the oxidized PANI and the negatively charged surface of the clay. X-ray diffraction analysis provides structural information of the prepared materials. The nanocomposites were characterized by transmission electron microscopy and their thermal degradation was investigated by thermogravimetric analysis. The weight loss suggests that the PANI chains in the nanocomposites have higher thermal stability than pure PANI. The electrical conductivity of the nanocomposites increased between 12 and 24 times with respect to the pure M and this increase was dependent on the cation-modification. The electrochemical behavior of the polymers extracted from the nanocomposites was studied by cyclic voltammetry and a good electrochemical response was observed.     

麦羟硅钠石/聚合物纳米复合材料研究进展

麦羟硅钠石（magadiite）是一种新型的层状纳米硅酸盐材料,由于其具有制备工艺简单、比表面积大、阳离子交换性能高、吸附性能强、层间膨胀性能好等优点,成为纳米材料提升聚合物性能最具有发展潜力的材料之一。本文主要综述了麦羟硅钠石/聚合物纳米复合材料的常用制备方法及其优缺点,包括聚合物插层法、单体原位插层聚合法、锚固插层聚合法。浅谈了国内外利用3种方法制备的基于聚苯乙烯、聚丙烯、环氧树脂、尼龙6、聚己内酯和聚甲基丙烯酸甲酯等多种聚合物的麦羟硅钠石/聚合物纳米复合材料,对在纳米复合材料结构中出现界面不相容、麦羟硅钠石分布不均匀的问题提出了解决方法,并阐述了麦羟硅钠石对纳米复合材料结构和性能的影响,最后展望了麦羟硅钠石/聚合物纳米复合材料的发展前景。