紫外光固化环氧丙烯酸酯/蒙脱土纳米复合材料的合成与表征

利用插层聚合合成了环氧丙烯酸酯／蒙脱土复合光固化树脂，并采用紫外光固化制备了环氧丙烯酸酯／蒙脱土纳米复合材料．用XRD、DSC对光固化过程中蒙脱土的插层和剥离行为进行了研究，并用FT-IR研究了蒙脱土对环氧-丙烯酸酯体系光固化速率的影响。力学试验证实，光固化后的环氧丙烯酸酯／蒙脱土纳米复合材料冲击与弯曲强度比原本体树脂分别提高了54％和10％．     

PP/蒙脱土纳米复合材料的制备及剪切粘度

应用双螺杆挤出机熔融插层制备出PP／蒙脱土纳米复合材料，X射线衍射表明，PP高分子链已插层进入有机蒙脱土片层之间。应用两种不同缝隙厚度的窄缝流变仪对PP及PP／蒙脱土纳米复合材料的剪切粘度及影响因素进行了研究。结果表明，PP／蒙脱土纳米复合材料为剪切变稀性流体。在190℃和210℃温度下，PP／蒙脱土纳米复合材料呈现类固体的非牛顿流体行为，剪切粘度随着剪切速率的升高逐渐降低。在230℃和剪切速率小于80s^-1的情况下，PP／蒙脱土纳米复合材料呈现类牛顿性流体行为。温度较高时,蒙脱土的含量对复合材料的剪切粘度的影响较为明显。     

苯乙烯-丙烯酸丁酯/蒙脱土纳米复合材料的阻燃性

以乳液插层聚合法合成苯乙烯-丙烯酸丁酯／蒙脱土纳米复合材料。X射线衍射结果表明，聚合物能够有效地插层到经过有机化处理的蒙脱土层间，且蒙脱土片层可以均匀地分散在苯乙烯-丙烯酸丁酯共聚物中。TGA分析表明，苯乙烯-丙烯酸丁酯／有机蒙脱土纳米复合材料的热稳定性有所提高．锥形量热仪测试和研究表明。复合材料的燃烧性能，包括热释放速率和质量损失，在蒙脱土含量为2％时，效果最好。     

紫外光固化聚氨酯丙烯酸酯/蒙脱土纳米复合材料的制备与表征

采用原位聚合方法合成了可紫外光固化的插层型聚氨酯丙烯酸酯／蒙脱土复合材料,通过紫外光固化后制备了聚氨酯丙烯酸酯／蒙脱土纳米复合材料。利用FT-IR、XRD等对材料的结构、蒙脱土的插层和剥离行为进行了表征,采用TGA和应力-应变方法对复合材料的热学及力学性能进行了测试。结果表明,当蒙脱土含量为4％～5％时,聚氨酯丙烯酸酯／蒙脱土纳米复合材料的耐热性能有了明显提高,而拉伸强度和撕裂强度比纯聚氨酯丙烯酸酯分别提高了100％和50％。     

LDPE/EVA/蒙脱土熔融插层纳米复合体系稳态剪切流变行为

用平行板和毛细管流变仪测定并研究了具有剥离结构的低密度聚乙烯(LDPE)／乙烯-醋酸乙烯共聚物(EVA)／蒙脱土纳米复合材料熔体的稳态剪切流变行为。研究结果表明,蒙脱土含量较低的复合物熔体,在低剪切速率下,即出现剪切变稀现象；而在较高剪切速率下,填充物浓度对体系熔体的剪切粘度影响较小；与基体树脂相比较,蒙脱土的加入,使其熔体的非牛顿指数降低,粘流活化能略有增加。     

UP/Na-MMT纳米复合材料的制备与性能

研究了UP／Na-MMT纳米复合材料的制备与性能，并考察了插层剂种类、有机蒙脱土加入量及离子交换量对复合材料性能的影响。结果表明，UP／Na-MMT纳米复合材料的XRD曲线中蒙脱土晶体结构的布拉格衍射峰已经消失，说明其晶层已被树脂撑开，达到纳米级分散；复合材料的耐热性能得到明显改善，其冲击强度和拉伸强度均有较大提高。     

桐油酸酐固化环氧树脂/蒙脱土纳米复合材料的研究

通过阳离子交换的方法将蒙脱土进行有机化处理，使蒙脱土由亲水性变成亲油性且层间距扩大，采用浇模固化成型法制备环氧树脂／桐油酸酐／蒙脱土纳米复合材料，并用XRD，DMTA等手段研究有机蒙脱土在环氧树脂中的剥离行为，研究发现，加入桐油酸酐固化剂后，粘土被剥离而得到剥离型的纳米复合材料，而且工艺条件的变化并不明显改变剥离的效果，DMTA测试表明桐油酸酐固化的环氧树脂的玻璃化转变温度随着粘土的加入而降低。     

苯乙烯-N苯基马来酰亚胺共聚物/蒙脱土纳米复合材料的制备与表征

分别使用无机蒙脱土和有机蒙脱土用乳液插层的方法制备了苯乙烯-N苯基马来酰亚胺共聚物／蒙脱土纳米复合材料，并用FT-IR、XRD、DSC、TGA对其进行了表征。结果表明，两种蒙脱土在St-NP-MI共聚物基体中，均已达到纳米分散，而且复合材料的热稳定性较纯St-NPMI共聚物有很大提高，尤其是有机蒙脱土纳米复合材料，其Ta提高60℃以上。     

MMT-PVAc/PA6/HDPE共混物中MMT纳米粒子对HDPE结晶性能的影响

采用γ-射线辐照法制备了聚醋酸乙烯酯(PVAc)及聚醋酸乙烯酯／蒙脱土(MMT)纳米复合材料。用熔融共混法制备了PVAc／PA6／HDPE与MMT—PVAc／PA6／HDPE共混物，通过DSC法研究了共混物中HDPE的非等温结晶行为，考察了MMT的存在对HDPE结晶行为的影响。结果表明，体系中MMT的存在有助于提高HDPE的结晶速率与晶体的完整性，单住时间内要达到不同的指定结晶度，所需的降温速率的变化幅度较小。     

碳纳米管-蒙脱土/环氧树脂复合材料的流变与固化特性

采用机械搅拌和离心分散的方法制备了多壁碳纳米管-有机蒙脱土/环氧树脂纳米复合材料。用X射线衍射和扫描电镜对复合材料的微观结构进行了分析和表征,研究了多壁碳纳米管含量对混杂体系流变性和固化特性的影响。结果表明,当有机蒙脱土含量为2%(质量分数,下同)时,蒙脱土在树脂体系中能够形成离散性结构,且与多壁碳纳米管形成一定程度的相互穿插结构。随着多壁碳纳米管含量的增加,混杂复合材料体系的黏度迅速上升,固化放热逐步降低。     

Monitoring the curing process of epoxy resin nanocomposites based on organo-montmorillonite – a new application of resin curemeter

Curing of a resin system is the critical and productivity controlling step in the fabrication of thermosetting matrix composites including nanocomposites. In the past few years, in the case of polymer-layered silicate nanocomposites, too many interests were taken in the material structure and properties, while only a few researches were carried on the cure behavior of this type of nanocomposite. The goal of the present work pays mainly attention to the cure kinetics for epoxy resin/organo-montmorillonite (Org-MMT)/2-ethyl-4-methyl-imidazole (2,4-EMI) nanocomposites. The experiments of monitoring curing process of nanocomposite materials are successively made via the HLX-II Resin Curemeter. The results derived from the non-equilibrium thermodynamic fluctuation theory indicated that the theoretical prediction is in good agreement with the experimental cure curve. The apparent activation energies were evaluated based on the gel time, t_g and relaxation time, τ, respectively. The increasing of cure temperature accelerated the cross-linking reactions for either nanocomposites or pure epoxy system. The addition of Org-MMT reduces the gel time, t_g as well as the completed cure time, t_c, and increases the rate of cure.     

聚丙烯/蒙脱土纳米复合材料的制备及结构

本文对钠基蒙脱土(Na—MMT)和经有机化处理过的有机蒙脱土(Org—MMT)分别与PP熔融共混进行研究，发现钠基蒙脱土和有机蒙脱土对PP力学性能有大幅度提高。同时，Na-MMT诱发了PP部分结晶晶型转变，经X射线衍射(XRD)和扫描电子显微镜(SEM)观察，发现Na—MMT和Org-MMT填充PP的粒子形态和界面形态有显著差别。     

Innovative green nanocomposites based on silicate clays/lignin/natural fibres

A new type of nanocomposite based on silicate clays, lignin and natural fibres has been elaborated by shear mixing in a twin-screw extruder. Either sepiolite or organically modified montmorillonite (Org-MMT) have been chosen for being dispersed into lignin/natural fibres system. The morphological aspect of the obtained nanocomposites has been controlled by Transmission Electronic Microscopy (TEM). For sepiolite-based nanocomposites, individual needles have been observed while Org-MMT-based nanocomposites have exhibited partial delamination of silicate layers into intercalated and exfoliated nanostructures. The properties of the specimens have been studied by thermogravimetry (TGA), Dynamic Mechanical Analysis (DMA) and flexural tests. Incorporation of 2% or 5% w/w of sepiolite does not influence the mechanical and thermal behaviour compared to the reference lignin/natural fibres composite while Org-MMT-based nanocomposites have shown improved properties.     

SiO2/M纳米复合材料的结构及催化性能

采用溶胶-凝胶法和超临界干燥法制备了SiO2/M(Cu,Co)纳米复合材料,对其结构、形貌进行了TEM和比表面分析,并研究了SiO2/M纳米复合材料的催化性能.结果表明,制得的SiO2/M纳米复合材料保留了SiO2气凝胶的纳米网络和高比表面积,金属组份Cu与Co均匀地分散在纳米级SiO2气凝胶骨架中,对CO的氧化反应以及CO-NO反应均表现出高的催化活性.     

偶联剂对PI/SiO2 纳米复合材料形态结构及性能的影响——Ι

用溶胶2凝胶法成功地合成了PI/SiO₂ 纳米复合材料, 并用紫外-可见光谱、红外光谱、扫描电子显微镜等手段对硅烷偶联剂对其微观形态结构以及密度、溶解性等性能的影响进行了研究。研究结果表明, 偶联剂的加入对两相间起到很好的增容作用, 使得二氧化硅无机粒子的粒径大大减小, 分散更加均匀, 在宏观上表现为透明性提高, 所得P I/SiO₂ 纳米复合材料的溶解性有明显改善, 而且随偶联剂加入量的增加, 效果更加显著。另外, PI/SiO₂ 纳米复合材料的密度也随偶联剂量的增加而增大。     

The effect of alternate heating rates during cure on the structure-property relationships of epoxy/MMT clay nanocomposites

This paper investigates the effect of both the mixing technique and heating rate during cure on the dispersion of montmorillonite (MMT) clay in an epoxy resin. The combination of sonication and using a 10 °C/min heating rate during cure was found to facilitate the dispersion of nanoclay in epoxy resin. These processing conditions provided a synergistic effect, making it possible for polymer chains to penetrate in-between clay galleries and detach platelets from their agglomerates. As the degree of dispersion was enhanced, the flexural modulus and strength properties were found to decrease by 15% and 40%, respectively. This is thought to be due to individual platelets fracturing in the nanocomposite. Complementary techniques including X-ray diffraction (XRD), small angle X-ray scattering (SAXS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and optical microscopy were essential to fully characterise localised and spatial regions of the clay morphologies.     

Preparation and thermal characteristics of silane-grafted polyethylene/montmorillonite nanocomposites

Intercalated methacryloylpropyltrimethoxysilane (VMMS)-grafted polyethylene (PE-g-VMMS) /organo-montmorillonite (OMT) nanocomposite was prepared by melt intercalation. Its morphology and thermal characteristics were carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analyses (TGA) and dynamic Fourier transfer infrared (FTIR) spectroscopy. The intercalated tactoids of silicate layers within PE-g-VMMS have been verified by XRD and TEM image. TGA profiles of the nanocomposite show that the presence of the silicates exerts a significant stabilization effect on thermal-oxidative degradation process from 250 to 375°C, but less effect above 375°C. Dynamic FTIR spectra reveal that this nanocomposite has a slower thermal-oxidative degradation rate of main chains than that of pure PE-g-VMMS, but a faster rate of the pendant VMMS grafts.     

聚氯乙烯/蒙脱土纳米复合材料的开发及研究

利用DSC的方法研究了纳米复合材料的玻璃化转变温度 ,测试了复合材料的力学性能 ,研究发现复合材料的力学性能与其玻璃化转变温度成线性关系 ,并随玻璃化转变温度的降低其力学性能提高。对复合材料进行热处理后 ,发现有机蒙脱土对聚氯乙烯的热降解引起的力学性能下降具有一定的抑制作用。     

Statistical modeling of the mechanical alloying process for producing of Al/SiC nanocomposite powders

Mechanical alloying process was modeled by statistical approach for producing of Al/SiC nanocomposite powders. The process variables included two dimensionless variables TV where T and V are milling time and speed, respectively, and P1/P2 where P1 and P2 are balls weight and powders weight, respectively. Responses of the process were crystallite size of the aluminum matrix, lattice strain of the aluminum matrix, and mean particle size of nanocomposite powders. The response variables were obtained by X-ray diffraction patterns (XRD), transmission electron microscopy (TEM), and laser particle size analyzer (LPSA). Two statistical models namely, fixed effects and regression model were developed. Analysis of variance (ANOVA) at 5% levels of significance for fixed effects model and 1% for regression model were performed. Results showed that P1/P2 has a significant effect on the crystallite size, and lattice strain of the aluminum matrix and TV has a significant effect on the crystallite size, and lattice strain of the aluminum matrix as well as mean particle size of nanocomposite powders. ANOVA for regression model showed that the linear effects of TV and P1/P2 variables were significant for crystallite size, lattice strain of the aluminum matrix, and mean particle size of nanocomposite powders. The final regression models were checked and accepted by residual analysis.     

聚丙烯/有机蒙脱土纳米复合材料的制备及性能

以马来酸酐接枝低分子量的聚丙烯(M APP)为相容剂,采用熔融插层法,制备了聚丙烯(PP)/有机蒙脱土(OMM T)纳米复合材料;采用微机控制电子万能试验机、悬臂梁冲击试验机研究了复合材料的力学性能;采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和偏光显微镜(POM)等对复合材料的微观结构进行了研究。结果表明,熔融插层法能够获得较好的插层效果,适量蒙脱土的加入使聚丙烯的球晶数量增多,球晶尺寸变小;复合材料的拉伸强度和冲击强度都是先增加后降低,总体上来说,拉伸强度高于纯聚丙烯,冲击强度与纯聚丙烯相近。