乳液插层法制备丁苯橡胶/天然橡胶/蒙脱土纳米复合材料的研究

采用乳液插层法制备了丁苯橡胶/天然橡胶/蒙脱土（SBR/NR/MMT）纳米复合材料。采用透射电子显微镜研究了复合材料的亚微观形态,并对复合材料的性能进行了研究。透射电镜结果显示,制备出了插层型的SBR/NR/MMT复合材料。当蒙脱土含量较低时,SBR/NR/MMT纳米复合材料的力学性能随蒙脱土用量的增加而增大。SBR/NR/MMT复合材料的耐油性能随蒙脱土含量的增加而提高。蒙脱土的加入对纳米复合材料的耐磨性能没有太大影响。     

醛酸共聚物/蒙脱土纳米复合材料的制备及性能研究

用水溶性聚合单体甲基丙烯酸和丙烯醛在钠基蒙脱土层间直接原位插层聚合,制备了水溶性醛酸共聚物/蒙脱土纳米复合材料。考察了引发剂用量及蒙脱土用量对纳米复合材料结构及应用性能的影响,并用X射线衍射和傅立叶变换红外光谱对纳米复合材料的结构进行了表征。研究结果表明:用坯革质量6%的纳米复合材料结合质量分数2%铬粉鞣制,可使坯革的收缩温度达90℃以上,增厚率达到70%以上,与常规铬鞣相比,可减少75%的铬粉用量。FTIR和XRD结果表明,所制备的纳米复合材料属于剥离型纳米复合材料,甲基丙烯酸与丙烯醛在蒙脱土层间发生了原位聚合。     

聚乙烯-乙烯醇/蒙脱土纳米复合材料结晶行为研究

以十六烷基季铵盐有机化蒙脱土(MMT)为无机相,以乙烯-乙烯醇共聚物为基体,通过熔融插层法制备了聚乙烯-乙烯醇/有机蒙脱土(EVOH/MMT)纳米复合材料,利用示差扫描量热仪(DSC)研究了EVOH/MMT复合材料的结晶行为.结果表明:MMT与EVOH插层后使EVOH/有机蒙脱土纳米复合材料的熔点和熔融热降低.经季铵盐处理过的蒙脱土片层在EVOH/有机蒙脱土纳米复合材料结晶过程中的异相成核作用不明显.在相同结晶条件下,EVOH/MMT纳米复合材料的结晶速率比EVOH慢.MMT的加入使EVOH/MMT纳米复合材料的熔融温度(Tm)从EVOH的180.7℃降低到175.2℃,结晶温度(Tc)从EVOH的157.9℃降低到153.1℃,而玻璃化转变温度(Tg)却较EVOH升高了大约2.6℃.     

含氮相容剂对聚丙烯/蒙脱土复合材料阻燃性能的影响

以N-羟甲基丙烯酰胺接枝聚丙烯(PP-g-NHA)为相容剂,采用熔融插层法,制备聚丙烯(PP)/蒙脱土(MMT)纳米复合材料;采用X射线衍射仪(XRD)、偏光显微镜(POM)、差式扫描量热仪(DSC)和氧指数仪(LOI)等对复合材料的微观结构和性能进行了研究。结果表明PP-g-NHA能有效地改善PP与MMT的相容性,当蒙脱土用量为5%、PP-g-NHA用量为15%时,PP/PP-g-NHA/MMT纳米复合材料的极限氧指数(LOI)由PP的18提高到23。X射线衍射(XRD)测试表明,PP已经插层进入到蒙脱土片层中,当蒙脱土用量为5%、PP-g-NHA用量为5%时插层效果最好,DSC分析结果表明,复合材料的熔融温度和分解温度都有所上升。     

聚氯乙烯/蒙脱土纳米复合材料的研究

采用熔融插层法制备了聚氯乙烯(PVC) /蒙脱土(MMT)纳米复合材料并进行了表征,研究了PVC/MMT纳米复合材料的力学性能。结果表明:PVC进入到有机MMT的片层间形成了纳米复合材料,但PVC不能进入钠基MMT的片层间,形成纳米复合材料;蒙脱土的加入提高了PVC的力学性能,而且PVC/有机MMT纳米复合材料的拉伸和冲击强度总是优于PVC/钠基MMT复合材料;对PVC/有机MMT纳米复合材料而言,复合材料的V型缺口冲击比U型缺口冲击敏感,其力学性能随热处理时间延长而降低,但PVC/有机MMT复合材料比PVC/钠基MMT的抗热性好。     

聚苯胺/蒙脱土纳米材料的制备及改性环氧应用

将苯胺直接插层到有机蒙脱土(MMT)片层间,以过硫酸铵为氧化剂,原位聚合制备了聚苯胺(PANI)/蒙脱土纳米复合材料。傅里叶变换红外分析、X射线衍射分析和透射电镜观察表明,当MMT的用量为苯胺质量的10%以下时,可制得纳米级复合材料。考察PANI/MMT纳米复合粉末对环氧树脂力学性能、热性能的影响表明:蒙脱土以1nm厚的剥离片层形式分散在环氧树脂中时,材料的力学性能和热性能都有明显改善,这与所制备的有机无机纳米结构有直接的关系。     

原位插层法制备SMA/MMT纳米复合材料

采用原位聚合的方法制备了苯乙烯马来酸酐无规共聚物（SMA）/蒙脱土（MMT）纳米复合材料,研究了MMT的用量对插层效果的影响.研究表明,采用原位聚合的方法可制得SMA/MMT纳米复合材料,随着MMT用量的增加,SMA/MMT纳米复合材料逐渐由插层型过渡到部分剥离.并且将原位聚合所得SMA/MMT纳米复合材料再次进行熔融插层后,可得到剥离效果更为明显的纳米复合材料.制得的SMA/MMT纳米复合材料具有较好的加工性能.     

甲基丙烯酸-丙烯醛共聚物/蒙脱土纳米复合材料的合成与性能

采用水溶性聚合单体甲基丙烯酸和丙烯醛在钠基蒙脱土层间直接原位插层聚合制备水溶性甲基丙烯酸-丙烯醛共聚物/蒙脱土纳米复合材料,并采用X射线衍射、透射电镜、红外光谱、热分析仪等对纳米复合材料的结构进行表征.结果表明:聚合物分子与黏土片层之间具有相互作用,甲基丙烯酸和丙烯醛在蒙脱土层问成功发生了聚合,所制备的纳米复合材料属于剥离型纳米复合材料.与未改性的聚合物基体相比,纳米复合材料的热分解温度提高了20多度.与纯铬粉鞣制的胶原相比,采用6%(质量分数,下同)纳米复合材料结合2%铬粉处理胶原可使胶原的各方面性能均得到较大改善,同时,废液中的铬含量减少了50%以上.     

聚二烯丙基二甲基氯化铵-丙烯酰胺-乙二醛/纳米插层复合蒙脱石的制备及性能

用二烯丙基二甲基氯化铵(diallyldimethylammonium chloride, DM)、丙烯酰胺(acrylamide, AM)在不同用量的蒙脱石(montmorillonite, MMT)中插层环化聚合,制备出聚二烯丙基二甲基氯化铵-丙烯酰胺(polymer diallyldimethylammonium chloride-acrylamide, PDM-AM)/纳米插层复合MMT;进而与乙二醛(glyoxal, GL)反应,制备了系列聚二烯丙基二甲基氯化铵-丙烯酰胺-乙二醛(polymer diallyldimethylammonium chloride-acrylamide-glyoxal, PDM-AM-GL)/纳米插层复合MMT.红外光谱结果表明:在MMT的存在下,单体成功发生聚合.X射线衍射和透射电镜结果表明:MMT的质量分数(下同)为4%时,PDM-AM-GL/纳米插层复合MMT中MMT的层间距达到最大值,为插层型纳米复合材料.PDM-AM-GL/纳米插层复合MMT经预鞣、再用2%铬粉鞣制后的结果表明:坯革的耐湿热稳定性、填充性、抗张强度、撕裂强度均优于单独采用2%铬粉鞣制的坯革.     

聚乳酸/蒙脱土纳米复合材料研究进展

分析了聚乳酸(PLA)/蒙脱土(MMT)纳米复合材料的结构,介绍了溶液插层复合法、原位插层复合法、熔融插层复合法等PLA/MMT纳米复合材料的制备方法,从力学性能、热稳定性能、降解性能、气体阻隔性能等方面阐述了PLA/MMT纳米复合材料的性能,并对PLA/MMT纳米复合材料的发展前景进行了展望。     

Surface modification of montmorillonite with novel modifier and preparation of polystyrene/montmorillonite nanocomposite by in situ radical polymerization

Exfoliated polystyrene/organo-modified montmorillonite nanocomposite was synthesized through in situ free radical polymerization by dispersing a modified reactive organophilic montmorillonite layered silicate in styrene monomers. The original montmorillonite (MMT) was modified by a novel cationic surfactant. A cationic initiator, consisting of a quaternary ammonium salt moiety, α-phenyl chloro acetyl chloride moiety, and 9-decen-1-ol moiety, was intercalated into the interlayer spacing of the layered silicate. Modified MMT clays were then dispersed in styrene monomers and subsequently polymerized by a free-radical in situ polymerization reaction to yield polystyrene/montmorillonite nanocomposite. The structure of obtained modifier was investigated by proton nuclear magnetic resonance (¹H NMR) and Fourier-transform infrared (FT-IR) spectroscopy. The exfoliating structure of nanocomposite was probed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Comparing with pure polystyrene, the nanocomposite showed much higher decomposition temperature and higher glass transition temperature (T_g).     

蒙脱石有机化对PVA/蒙脱石复合薄膜的性能影响

以精制钠基蒙脱石(Na-MMT)、有机化蒙脱石(OMMT)和聚乙烯醇(PVA)为原料,通过水溶液插层-流延成膜法制备纳米复合薄膜。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和热重分析(TGA)对复合材料的结构和性能进行表征,重点探讨蒙脱石有机化对PVA/MMT复合薄膜性能的影响。结果表明Na-MMT和OMMT纳米颗粒在PVA基体中均得到了良好分散;有机改性剂的存在促使PVA/MMT复合薄膜的MMT片层间距扩撑更大,但由于其与PVA相容性较差,导致有效插入MMT片层间的PVA分子较少,PVA/MMT复合薄膜的热稳定性改善效果不明显。     

A New Type of Dispersant [Sodium Salt of Styrene–Methacrylic Acid Copolymer (SSMA)/Montmorillonite (MMT) Nanocomposite] for Pesticide Water Dispersible Granules

A new type of dispersant [sodium salt of styrene–methacrylic acid copolymer (SSMA)/montmorillonite (MMT) nanocomposite] with different content of the MMT was synthesized through in situ solution free radical copolymerization. X‐ray diffraction measurements and electron microscopy observations prove that SSMA molecules can enter the interlayer space of MMT and form an intercalated structure. There are both fully intercalated and partly intercalated structures in the nanocomposites, which are related to the loading content of MMT. Transmission and scanning electron microscopy images indicate that the exfoliation degree of MMT in the nanocomposites decrease with increasing MMT content. Infrared spectroscopy (FTIR) analysis shows that there are hydrogen‐bonding interactions between carboxyl groups of SSMA and hydroxyl groups of MMT. Atrazine water dispersible granules were prepared by using SSMA/MMT nanocomposite as dispersant and their suspensibility in aqueous solution was determined to evaluate the dispersion properties of the nanocomposite. The results show that the addition of MMT can not only increase the steric effect of the SSMA to improve its dispersion properties, but also reduce the production cost of SSMA. The optimum loading content of MMT is 10 wt%.     

Enhancing antibacterial properties of polypropylene/Cu‐loaded montmorillonite nanocomposite filaments through sheath–core morphology

Polypropylene (PP) loaded with copper‐exchanged montmorillonite (Cu‐MMT) nanocomposite filaments and films with excellent antimicrobial activity have been reported for the first time. A sheath–core morphology filament in which only the sheath contains Cu‐MMT was prepared for maximizing bioactivity. Sodium MMT clay was modified to acid‐activated MMT and further to Cu‐MMT via an ion exchange process. The exchange operation was confirmed using wide‐angle X‐ray diffraction and energy‐dispersive X‐ray spectroscopy (EDX) which suggested increased interlayer spacing and confirmed the loading of copper in Cu‐MMT. Further, Cu‐MMT was melt‐mixed in PP in the form of PP/Cu‐MMT nanocomposite filament, film and sheath–core morphology PP/Cu‐MMT nanocomposite filament. The surface morphology and elemental composition of the nanocomposites were studied using scanning electron microscopy coupled with EDX. Transmission electron micrographs were obtained to understand the dispersion characteristics of Cu‐MMT phase in PP. X‐ray diffraction analysis of nanocomposites suggested increased crystallinity at lower loading due to heterogeneous nucleating action of MMT. The PP nanocomposite filaments and films were tested for antimicrobial activity against Gram‐negative bacterium Escherichia coli, which is the main pathogenic bacterium found abundantly in water, and were found to exhibit excellent antimicrobial activity. © 2018 Society of Chemical Industry     

Fabrication of Nanocomposite Powders of Carbon Nanotubes and Montmorillonite

Nanocomposite powders of carbon nanotubes (CNTs) and montmorillonite (MMT) were successfully synthesized by heating the mixed composites of polypropylene, nickel (Ni) catalyst, and organic-modified montmorillonite in large quantities after the Ni catalysts were removed. Transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, Raman spectroscopy, and scanning electron microscopy show the co-presence of CNTs and MMT. The interlayer distance of MMT was enlarged because of the CNTs, which result in MMT being partly exfoliated and buried in the CNTs. These current nanocomposite powders of CNTs and MMT with superstructure are therefore expected to be ideal fillers for high-performance polymer nanocomposites.     

改性蒙脱土对PET吹塑瓶阻隔性的影响

在水分散液中使蒙脱土与6－氨基已酸或对氨基苯甲酸进行插层反应制得有机改性蒙脱土。X射线衍射、热重分析和红外光谱测试结果表明，6－氨基已酸或对氨基本甲酸被插层到蒙脱土的晶格片层之间，使层间距增大在双螺杆挤出机中使聚对苯二甲酸乙二酯（PET）与改性蒙脱土进行熔融插层复合得到PET／改性蒙脱土复合材料，并用注－拉－吹工艺成型得到PET／改性蒙脱土复合瓶。阻隔性测试结果显示，PET／改性蒙脱土复合瓶对氧气的阻隔性比纯有明显提高。     

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%。     

Poly(methyl methacrylate)/clay nanocomposites by photoinitiated free radical polymerization using intercalated monomer

A series of poly(methyl methacrylate)/montmorillonite (PMMA/MMT) nanocomposite were prepared by successfully dispersing the inorganic nanolayers of MMT clay in an organic PMMA matrix via in situ photoinitiated free radical polymerization. Methyl methacrylate monomer was first intercalated into the interlayer regions of organophilic clay hosts by “click” chemistry followed by a typical photoinitiated free radical polymerization. The intercalated monomer was characterized by FT-IR spectroscopy, elemental analysis and thermogravimetric analysis methods. The intercalation ability of the modified monomer and exfoliated nanocomposite structure were confirmed by X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Thermal stability of PMMA/MMT nanocomposites was also studied by both differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).     

PE/MMT纳米复合材料的研究进展

介绍蒙脱土(MMT)及其纳米复合材料的结构、特点及聚乙烯(PE)/MMT纳米复合材料的制备原理和方法,并对PE/MMT纳米复合材料的国内外研究进展进行了综述,指出今后PE/MMT纳米复合材料的研究重点是先对PE进行改性,以增加PE与MMT片层的粘结力。     

Spinning and properties of poly(ethylene terephthalate)/organomontmorillonite nanocomposite fibers

By in situ polycondensation, a intercalated poly(ethylene terephthalate)/organomontmorillonite nanocomposite was prepared after montmorillonite (MMT) had been treated with a water‐soluble polymer. This nanocomposite was produced to fibers through melt spinning. The resulting nanocomposite fibers were characterized by X‐ray diffraction (XRD), differential scanning calorimeter (DSC), and transmission electron microscopy (TEM). The interlayer distance of MMT dispersed in the nanocomposite fibers was further enlarged because of strong shear stress during processing of melt spinning. This was confirmed by XRD test and TEM images. DSC test results showed that incorporation of MMT accelerated the crystallization of poly(ethylene terephthalate) (PET), but the crystallinity of the drawn fibers just had a little increasing compared with that of neat PET drawn fibers. Also compared with pure PET drawn fibers, tensile strength at 5% elongation and thermal stability of the nanocomposite fibers were improved. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1443–1447, 2005