聚乙烯(PE)/OMMT纳米复合材料的结构、形态和性能

选择一种新型的有机改性蒙脱土(OMMT),在不加任何相容剂的条件下,利用熔融挤出法分别制备出了剥离型高密度聚乙烯/蒙脱土纳米复合材料、插层型线型低密度聚乙烯/蒙脱土和低密度聚乙烯/蒙脱土纳米复合材料。利用透射电子显微镜观察制备的复合材料的亚微观分散形态,确定了制备出的纳米复合材料的类型,并对不同亚微观结构形态进行了分析讨论,得出了不同分子结构影响纳米复合材料形成不同分散形态的结论;对于3种纳米复合材料的物理性能测试结果表明,不同亚微观分散形态的纳米复合材料的纳米效应不同,对物理性能的影响各有不同,对于聚合物/蒙脱土纳米复合材料的深入研究具有重大意义,同时分散均匀的纳米复合材料结构对于进一步研究聚乙烯纳米膜的气体阻隔性等性能奠定了良好的基础。     

OMMT/FKM纳米复合材料的结构和性能

采用机械混炼法制备有机蒙脱土（OMMT）／氟橡胶（FKM）纳米复合材料，研究复合材料的微观结构和性能。结果表明，OMMT／FKM纳米复合材料为剥离型复合材料；与FKM相比，OMMT／FKM纳米复合材料具有较优的物理性能、热稳定性和耐溶剂性能。     

溴化丁基橡胶/天然橡胶/有机蒙脱土纳米复合材料的结构与性能研究

采用机械混炼法制备了溴化丁基橡胶/天然橡胶/有机蒙脱土(BIIR/NR/OMMT)纳米复合材料,对其亚微观结构与性能进行了表征。实验结果表明:OMMT片层以剥离形式均匀分散于橡胶基体中;OMMT能够明显促进橡胶硫化反应,并使BIIR和NR两相的交联同步性加强;纳米复合材料具有优异的物理机械性能和热稳定性能。     

硅烷偶联剂对OMMT/NR纳米复合材料结构与性能的影响

采用混炼插层法制备有机蒙脱土(OMMT)/NR纳米复合材料,研究硅烷偶联剂对其结构和性能的影响.结果表明,与NR相比,OMMT/NR纳米复合材料的物理性能,热稳定性和动态力学性能均有所提高;采用硅烷偶联剂KH-560改性的OMMT制备的纳米复合材料各项性能均优于采用硅烷偶联剂KH-550改性的OMMT制备的纳米复合材料.     

HIPS/OMMT复合材料阻燃性能的研究

采用挤出工艺、熔融插层法制备了高抗冲聚苯乙烯／有机蒙脱土（HIPS／OMMT）复合材料。通过X射线衍射仪和扫描电镜研究蒙脱土和复合材料的微观结构，发现OMMT的层间距由改性前的1.52nm增大到2．25nm，复合材料中的OMMT片层被剥离开来，与HIPS基体形成了剥离型的复合材料。用基于耗氧原理的锥形量热仪测试并分析HIPS／OM—MT复合材料的阻燃性能。结果表明，与纯的HIPS相比，HIPS／OMMT复合材料的热释放速率及其峰值、质量损失速率均明显降低，且随OMMT添加量的增加，复合材料的热释放速率峰值降低愈明显；通过对复合材料的阻燃性能和微观结构的分析，探讨了其阻燃机理。     

有机蒙脱土在冬季轮胎胎冠胶中的应用研究

采用机械混炼法制备了天然橡胶/溴化丁基橡胶/有机蒙脱土(NR/BiIR/OMMT)纳米复合材料,并对其亚微观结构与性能进行了研究.结果表明,NR/BIIR/OMMT复合材料为剥离型纳米复合材料,具有优异的力学性能;OMMT对NR/BIIR共混胶的耐寒性能影响较小,在制备冬季轮胎胎冠胶方面具有优异的工业应用前景.     

几种丁腈橡胶/有机蒙脱土纳米复合材料的制备与对比表征

选择几种自制的有机蒙脱土,利用双辊直接混炼法与丁腈橡胶复合,测试材料的力学性能,确定出了最佳的有机蒙脱土牌号。利用透射电子显微镜观察,确定制备出了半剥离型的丁腈橡胶/有机蒙脱土（NBR/OMMT）纳米复合材料;测试材料的应力-应变曲线表征了不同有机蒙脱土含量的纳米复合材料的力学性能;利用溶剂渗透性测试实验表征了纳米复合材料的耐油性提高;通过透射电子显微镜观察发现,采用有机蒙脱土预凝胶,成功地制备了全剥离型的NBR/OMMT纳米复合材料。     

EPDM/有机蒙脱土纳米复合材料的制备和性能研究

以EPDM接枝马来酸酐作相容剂，用一段密闭熔融混炼、二段开炼机混炼的方法制备了EPDM／有机蒙脱土(OMMT)纳米复合材料，并对其性能进行了研究。结果表明，熔融混炼使EPDM分子链开始插入OMMT片层间，致使OMMT片层间距有所增大；开炼机混炼使OMMT片层间距进一步增大；硫化后，OMMT片层剥离，以纳米级尺寸均匀分布于EPDM基体中。与EPDM胶料相比，EPDM／OMMT纳米复合材料的损耗因子小，玻璃化温度高，储能模量大，物理性能显著提高。     

BIIR/OMMT纳米复合材料的阻透性能和耐寒性能

采用机械混炼法制备了溴化丁基橡胶/有机蒙脱土(BIIR/OMMT)纳米复合材料,采用SEM和XRD对其亚微观结构进行了表征,并对其耐寒性能和阻透性能进行了研究。实验结果表明:OMMT片层以剥离状态分散于BIIR基体中;添加OMMT之后,BIIR的交联密度明显提高;OMMT能够略微降低BIIR的耐寒性能;OMMT片层具有优异的阻透效应,能够明显提高BIIR的热稳定性能和耐油性能。     

PB-TPE/OMMT复合材料的结构与性能研究

采用烷基季铵盐类有机插层剂十六烷基三甲基溴化铵（CTAB）对蒙脱土（MMT）进行了改性处理,制备了有机化蒙脱土（OMMT）,并对聚丁烯-1热塑性弹性体（PB-TPE）进行了马来酸酐接枝改性（PB-TPE-g-MAH）。以PB-TPE-g-MAH为相容剂,通过熔融插层法制备了PB-TPE-g-MAH/OM-MT纳米复合材料。采用傅立叶变换红外光谱（FTIR）、X-衍射（XRD）、透射电镜（TEM）等手段分析了材料结构。结果表明：OMMT在PB-TPE-g-MAH体系中得到了插层和部分剥离,使有机蒙脱土片层间距由原来的1.96 nm增加到3.81 nm。与不含蒙脱土的PB-TPE相比,PB-TPE-g-MAH/OMMT纳米复合材料的拉伸性能得到明显提高。     

Studies on the viscoelasticity of poly(trimethylene terephthalate)/poly(ethylene–octene)/organomontmorillonite nanocomposites

The viscoelasticity of poly(trimethylene terephthalate)/maleinized poly(octene‐ethylene) copolymer/organomontmorillonite (OMMT) nanocomposites were investigated at both liquid and glassy states by using the rotational rheometer and dynamic mechanical analysis, respectively. The viscoelasticity results suggest that OMMT has many important influences on the structure, modulus, toughness, and cold‐crystallization of the nanocomposites. The OMMT has a strip‐like sheet morphology in the polymer matrix and when OMMT content increases to 4 wt%, the physical network‐like structure begins to form in the nanocomposites. The pseudoplasticity of the melts is increased by OMMT. In addition, the complex viscosity, storage modulus, and viscous behavior of the melts are increased with increasing OMMT content. The creep resistance of the nanocomposites is improved by OMMT, and it plays an important role on reinforcing the melts. The stress relaxation of the melts suggests that the nanofillers can not only enhance the interfacial interactions of the nanocomposites but also inhibit the recovery of the polymer chain segments. At glassy state, the nanocomposites' storage modulus increases with increasing OMMT content. As glass transition occurs, the loss factor and loss modulus suggest that OMMT toughens the polymer matrix. At rubber‐elastic state, OMMT depresses the cold‐crystallization of the polymer matrix due to its limitation effect on the motion of molecular chains. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

The effect of clay modification on the mechanical properties of poly(methyl methacrylate)/organomodified montmorillonite nanocomposites prepared by in situ suspension polymerization

Poly(methylmethacrylate) (PMMA)/montmorillonite (MMT) nanocomposites were prepared by in situ suspension polymerization. MMT was previously organically modified by different modification agents [dioctadecyl dimethyl ammonium chloride (DODAC) and methacrylatoethyltrimethyl ammonium chloride (MTC)] and different modification method (cation‐exchange reaction and grafting reaction), ultimately giving rise to five kinds of organomodified MMT (OMMT). The structure of the OMMT was studied by Wide angle X‐ray diffraction (WAXD) and Fourier transform infrared spectroscopy (FTIR). Meanwhile, the structure of the PMMA/MMT nanocomposites microspheres was also investigated by WAXD. The molecular weight of the polymers extracted from PMMA/MMT nanocomposites was measured by gel permeation chromatograph (GPC). Finally, the mechanical properties of these PMMA/MMT nanocomposites were studied in detail. It was found that large interlayer spacing (d₀₀₁) of OMMT could not entirely ensure an exfoliated structure of resultant PMMA/MMT nanocomposites, while OMMT with relative small d₀₀₁ could still yield exfoliated structure as long as the compatibility between OMMT and polymer matrix was favorable. In addition, the results of mechanical investigation indicated that the compatibility between OMMT and PMMA matrix turned out to be the dominant factor deciding the final mechanical properties of PMMA/MMT nanocomposites. POLYM. COMPOS., 37:1705–1714, 2016. © 2014 Society of Plastics Engineers     

Studies on morphologies and thermal properties of poly(lactic acid)/polycaprolactone/organic‐modified montmorillonite nanocomposites

Poly(lactic acid)/organic montmorillonite (PLA/OMMT) nanocomposites were prepared via twin‐screw extrusion. Montmorillonite (MMT) was firstly organically modified to improve the compatibility between polyester and MMT. The effects of ratio between PLA and OMMT and the addition of polycaprolactone (PCL), as a compatilizer, on the properties of PLA/OMMT nanocomposites were studied. The morphology and the properties of the nanocomposites were characterized by XRD, DSC, and TEM. Using OMMT, the intercalated structure was formed during the extrusion process and the OMMT interlayers space was enlarged. More OMMT content was apt to form thicker structure with more stacked individual silicate layers, which led to lower degree of crystallinity of PLA. It showed that 1 phr OMMT could result in the largest interlayers space and the best crystallization state. PCL can effectively increase the binding force between two phases and improve the order of the nanocomposites. In addition, the annealing after treatment can form regular structure and enhance the thermal properties of nanocomposites. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Preparation of Cu/OMMT/LLDPE nanocomposites and synergistic effect study of two different nano materials in polymer matrix

Cu/OMMT (organo-montmorillonite)/LLDPE (linear low-density polyethylene) nanocomposites were prepared via melt mixing combined with melt extruding process. X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectra, scanning electron microscope (SEM), and transmission electron microscopy (TEM) were employed to characterize the resultant nanocomposites. The results showed that the OMMT layers were exfoliated and the nano-Cu particles were distributed uniformly in the polymer matrix. And the introduction of nanofiller into LLDPE matrix had little effect on the crystallinity of the polymer. The salt spray tests showed that OMMT and nano-Cu could improve the anticorrosion properties of LLDPE matrix, respectively. And the coexistence of OMMT and nano-Cu in Cu/OMMT/LLDPE nanocomposites could produce a synergistic effect on enhancing the anticorrosion properties. Furthermore, the co-incorporation of OMMT and nano-Cu into the polymer matrix also increased the thermal-oxidative stability and mechanical properties of LLDPE matrix significantly, as compared with the Cu/LLDPE and OMMT/LLDPE nanocomposites due to the synergistic effect. The bactericidal properties evaluation showed that the bactericidal ability of Cu/OMMT/LLDPE increases with nano-Cu content effectively.     

Preparation and properties of raw lacquer/multihydroxyl polyacrylate/organophilic montmorillonite nanocomposites

Raw lacquer (RLA) has been widely used indoors for centuries in Asia. But its weak UV-resistant property limited its outdoor application. In this article, the UV-resistant property of lacquer film was significantly improved by solution intercalation method. The intercalated nanocomposites were obtained from RLA, multihydroxyl polyacrylate resin (MPA), and organophilic montmorillonite (OMMT). The structure and morphology of the RLA/MPA/OMMT nanocomposites were confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The variation of the film gloss and impact strength with different UV exposure time was also investigated. Owing to the dispersion of nanometer-sized OMMT in polymer matrix, the RLA/MPA/OMMT nanocomposites exhibited improved UV-resistant property. When the OMMT content is 3.0 wt%, the best physical–mechanical properties can be obtained. These results indicated that the solution intercalation with nanoparticles was an efficient and convenient method to improve the properties of raw lacquer.     

Effect of exfoliated organophilic montmorillonite on the structure and conductivity of polypropylene/polyaniline composites

This study concentrates on the effect of organophilic montmorillonite (OMMT) nanolayers on conductivity, structure, morphology, and mechanical properties of the polypropylene/polyaniline (PP/PANI) composites. The composite was prepared by in situ polymerization of aniline at different composition ratios in the presence of PP powder. The structure and conductivity of ternary PP/PANI/OMMT nanocomposites were compared with those of PP/PANI composites. DC electrical conductivity measurements indicated that electrical conductivity decreased in the presence of OMMT layers. Scanning electron microscopy showed that the surface of ternary nanocomposites have more rough regions. The interaction between PANI and OMMT was confirmed by Fourier transform infrared spectroscopy. The distribution of OMMT layers in the polymer matrix, as an effective parameter on the properties of nanocomposite, was investigated and confirmed using X‐ray diffraction and transmission electron microscopy. The results showed an exfoliated array for OMMT layers in the nanocomposite structure. The shear storage modulus for PP/PANI composites was lower than that for pure PP; however, it was increased for PP/PANI/OMMT nanocomposites. The data from the tensile and izod impact strength showed that the Young's modulus and izod impact strength were increased slightly by the addition of OMMT, whereas the elongation at break was decreased. POLYM. COMPOS., 38:699–707, 2017. © 2015 Society of Plastics Engineers     

机械共混法制备NR/SBR/OMMT纳米复合材料及其性能

选择不同牌号的有机蒙脱土（OMMT）,利用机械共混法制备了NR/SBR/OMMT纳米复合材料。测试了复合材料的力学性能,选择出了最佳牌号OMMT。不同含量的OMMT与共混胶复合后力学性能的测试结果表明：当OMMT含量仅为3份时,拉伸强度和断裂强度分别提高了90％和63%;利用X射线衍射和透射电子显微镜研究了复合材料的亚微观结构,观察结果显示制备出了分散均匀的剥离型NR/SBR/OMMT纳米复合材料,同时OMMT在轮船工业配方中的优异性能预示其良好的应用前景。     

Preparation,morphology, and properties of organo‐montmorillonite/nitrile butadiene rubber nanocomposites

Organo‐montmorillonite/nitrile butadiene rubber (OMMT/NBR) nanocomposites were prepared by co‐coagulating process, and then were combined with rubber ingredient and vulcanized by traditional rubber mixing procedure. The SEM micrographs of the nanocomposites showed uniform dispersion of the OMMT particles in NBR. The ATR‐FTIR spectra illustrated the existence of montmorillonite in the nanocomposites. The XRD patterns further indicated the structure of nanocomposites, and confirmed an effective intercalation of NBR in the interlayer space of the OMMT. Moreover, the tensile strength and elongation at break of nanocomposites tended to increased rapidly with increasing OMMT loading, due to the reinforcing properties of OMMT to NBR. In addition, the TGA and DTA curves demonstrated the thermal performance of the nanocomposites enhanced. Furthermore, the addition of OMMT accelerated the vulcanization process. POLYM. COMPOS., 34:1809–1815, 2013. © 2013 Society of Plastics Engineers     

Poly(methyl methacrylate)/montmorillonite nanocomposites prepared by bulk polymerization and melt compounding

This article focuses on structural, thermal, and mechanical properties of nanocomposites in dependence of preparation method and poly(methyl mathacrylate) (PMMA)/organically modified montmorillonite (OMMT) ratio. PMMA/OMMT nanocomposites were prepared by bulk polymerization and by melt compounding. Properties of nanocomposites of the same composition prepared by the two methods were compared. It was observed that nanocomposites prepared via melt compounding at 200°C had a highly oriented structure with lower interlayer spacing values than nanocomposites prepared via bulk polymerization. Two reasons for the observed smaller interlayer spacing obtained by melt compounding were identified. The first is enhanced PMMA penetration and/or formation between layers in the case of bulk polymerization, which was confirmed by determination of stronger interactions between OMMT and PMMA by Soxhlet extraction, infrared spectroscopy, and differential dynamic calorimery. The second reason for smaller interlayer spacing for nanocomposites prepared by melt compounding is organic modifier degradation during melt compounding process, which was confirmed by thermogravimetric analysis. Both reasons lead to the fracture of melt compounded nanocomposites on the OMMT‐polymer interface, which was observed by scanning electron microscopy. For nanocomposites with disoriented structure and larger interlayer spacing prepared via bulk polymerization the fracture occurred in the polymer matrix. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Effects of different kinds of clay and different vinyl acetate content on the morphology and properties of EVA/clay nanocomposites

A series of EVA/clay nanocomposites and microcomposites have been prepared via melt-blending. Using four kinds of EVA with different vinyl acetate (VA) contents: 28, 40, 50 and 80 wt%, and four kinds of clay: three are organophilic clay (OMMT) and one unfunctionalized clay (Na-MMT), the effects of different VA content of EVA and the kinds of the clay on the morphology and properties of EVA/clay nanocomposites were systematically investigated. In previous studies, there are only two distinct nanostructures to distinguish polymer/clay nanocomposites: the intercalated and the exfoliated. But in this paper, we proposed a new nanostructure—‘the wedged’ to describe the dispersion degree of clay in nanocomposites, it means the sheets of clay were partly wedged by the chains of polymer. The wedged, the intercalated and the partially exfoliated structures of EVA/clay nanocomposites were characterized by X-ray diffraction (XRD) and by high-resolution transmission electron microscopy (HRTEM). The enhanced storage modulus of EVA/clay nanocomposites was characterized by dynamic mechanical thermal analysis (DMTA). The enhanced degree in the storage modulus of the OMMT on EVA/clay nanocomposites with the partially exfoliated and intercalated structure is much higher than that with wedged structure, and that with the higher VA content is higher than that with the lower. The thermal stabilities of EVA/clay nanocomposites were also studied by thermal gravimetric analysis (TGA).