一种新型的累托石/SBR纳米复合材料的结构与性能

采用乳液共混共凝法首次制备了累托石／SBR复合材料。TEM研究表明，累托石在SBR基体中的分散尺寸小于100nm。该材料的力学性能与蒙脱石／SBR纳米复合材料水平相当，但由于分散相形状系数略大，气密性和撕裂强度更优一些。累托石可望成为一类新的分散相填料。     

累托石/NR纳米复合材料的结构与性能研究

研究乳液法和熔体法制备的累托石／NR纳米复合材料的结构与性能。结果表明,乳液法累托石／NR纳米复合材料为层间无高分子插入的隔离型纳米复合材料,熔体法累托石／NR纳米复合材料为典型的插层型纳米复合材料;当应变小于100％时,熔体法制备的复合材料应力较大,当应变大于100％时,乳液法制备的复合材料应力较大;当累托石用量较小时,乳液法制备的复合材料撕裂强度高于熔体法制备的复合材料;乳液法和熔体法制备的两种复合材料热稳定性差别不大,均好于纯NR。     

累托石在聚合物纳米复合材料中的应用

介绍了一种用于聚合物纳米复合材料的新型层状硅酸盐材料——累托石粘土,从矿物的结构特点分析了它用于聚合物纳米复合材料的改性、插层、剥离的可行性及性能特点,还介绍了用累托石改性的尼龙6、聚丙烯、聚氨酯弹性体等纳米复合材料,其综合性能优于同类聚合物／蒙脱石纳米复合材料,     

SBR粘土纳米复合材料的气密性

对乳液法制备的SBR粘土纳米复合材料的气密性进行了研究,结果表明：SBR粘土纳米复合材料的气密性优于传统填料填充的硫化胶,且随温度的变化较小;填料的用量、形状以及与橡胶的结合性是影响气密性的主要因素;填充20份粘土的纳米复合材料气密性优于NR／SBR内胎,比IIR内胎差。     

累托石/丁腈橡胶纳米复合材料的结构与性能

用乳液共混共凝法制备了累托石／丁腈橡胶(NBR)复合材料,分别进行了透射电镜分析和X射线衍射分析,研究了其力学性能和气体阻隔性能。结果表明,累托石以厚度为10．00nm左右的晶束均匀分散于NBR中;累托石／NBR复合材料属于隔离型纳米复合材料;与传统的炭黑／NBR复合材料和白炭黑／NBR复合材料相比,累托石／NBR纳米复合材料具有高的邵尔A型硬度和300％定伸应力．尤其是其气体阻隔性能得到了显著提高。     

两种橡胶/有机累托石纳米复合材料的结构与性能

比较了用熔体法制备的有机累托石(OR)/丁苯橡胶(SBR)以及有机累托石(OR)/天然橡胶(NR)2种纳米复合材料的结构与性能.TEM和XRD对材料的分析显示,由于橡胶基体的性质差异,OR/SBR为典型的插层型结构,而OR/NR为插层型和部分剥离型混合结构.应力应变行为的研究表明,随着OR用量的增加,OR/SBR的拉伸强度和拉断伸长率均增大,这主要是分子链滑移和填料的取向造成的.对于拉伸结晶型橡胶NR,由于部分剥离型填料的增强作用,NR的定伸应力随填料用量的增加而逐渐提高.由于对结晶的阻碍作用,当OR用量为20份时,OR/NR的拉伸强度有所降低.纳米累托石的加入可以显著提高SBR和NR的硬度和撕裂强度.热失重分析表明,OR/橡胶纳米复合材料与相应的纯橡胶相比,热稳定性提高,在NR体系中更为显著.     

累托石纳米复合材料的结构和性能

以具有层状硅酸盐结构的累托石(REC)为主体、烷基季铵盐为改性剂合成了有机累托石(OREC)，以有机累托石和环氧树脂复合制备纳米复合材料。累托石含量在0.8％(w)时，纳米复合材料具有最佳力学和热学性能，其中冲击强度增加120％，断裂伸长率增加330％，玻璃化转变温度提高28℃。用X-小角衍射法、透射电镜和红外吸收光谱研究了材料的微观结构，结果表明层状累托石和环氧树脂发生了化学反应，并观测到层状累托石完全剥离和插层两种结构形态。累托石在低含量时容易形成剥离型。     

环氧树脂/有机累托石纳米复合材料的研究

用十二烷基二甲基苄基氯化铵对累托石进行有机化处理，采用不同量的有机累托石与环氧树脂进行原位插层聚合，制得环氧树脂／有机累托石纳米复合材料，采用红外光谱分析、X射线衍射分析、扫描电镜分析、差示扫描量热分析和力学性能测试研究了有机累托石在环氧树脂中的分散性、纳米复合材料的力学性能和热性能。结果表明，有机累托石含量为3份时纳米复合材料的综合性能最佳，冲击强度和弯曲强度分别提高40％和33％；热变形温度和玻璃化转变温度分别提高30℃和11．5℃；而其热稳定性与纳米累托石粒子的分布和界面作用有关。     

有机累托石改性不饱和聚酯／玻璃纤维复合材料的研究

采用有机累托石改性不饱和聚酯，以改性的不饱和聚酯为基体，以两种玻璃布(EW210、CWR400-90)为增强材料，以两个不同凝胶时间的不饱和聚酯树脂体系制备三种有机累托石改性的不饱和聚酯磁璃纤维复合材料(UPB1、UPB2、UPB3)。测试了不饱和聚酯/玻璃纤维的力学性能；研究了复合材料的耐湿热性及耐介质性能；利用扫描电镜及透射电镜分析了复合材料的增强机理。结果表明，采用有机累托石改性不饱和聚酯所制备的不饱和聚酯／玻璃纤维复合材料的综合力学性能优于纯不饱和聚酯／玻璃纤维复合材料。     

熔融插层法制备累托石/聚碳酸亚丙酯纳米复合材料的研究

采用熔融插层法制备了有机化累托石/聚碳酸亚丙酯纳米复合材料,通过X射线衍射、原子力显微镜、热重分析法测试了复合材料的结构与热性能。结果表明:聚碳酸亚丙酯能插层于累托石片层中,累托石/聚碳酸亚丙酯纳米复合材料的耐热性有了很大程度的提高。     

Preparation,structure, and properties of a novel rectorite/styrene–butadiene copolymer nanocomposite

Rectorite/styrene–butadiene copolymer (SBR) nanocomposite was prepared by cocoagulating SBR latex and rectorite/water suspension. Transmission electron microscopy showed that the layers of rectorite were well dispersed in the SBR matrix and the aspect ratio (width/thickness) of it was higher than that of montmorillonite (MMT). X‐ray diffraction indicated that the nanocomposite produced by this method was of neither intercalated type nor exfoliated type. The gas barrier properties and mechanical properties of the novel nanocomposites were excellent. The nanocomposites are expected to be candidates for tire tube or inner materials. Rectorite appears to be a promising filler for the nanocomposite. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 324–328, 2005     

粘土/丁苯橡胶纳米复合材料在全钢载重子午线轮胎气密层中的应用

研究粘土/丁苯橡胶（SBR）纳米复合材料的结构和性能及其在全钢载重子午线轮胎气密层中的应用。结果表明：粘土在复合材料中分散均匀,复合材料气密性能优异;气密层采用粘土/SBR纳米复合材料的全钢载重子午线轮胎成品性能符合企业标准要求,实际使用状况良好。     

甘油和芳烃油对累托石/SBR纳米复合材料性能的影响

采用乳液共沉法制备累托石/SBR纳米复合材料,研究甘油或芳烃油对纳米复合材料性能的影响.结果表明:加入甘油或芳烃油均可改善复合材料的加工性能.加入甘油可以提高复合材料的硫化速率,降低硫化胶的分子链运动能力,提高拉伸强度,且不会降低复合材料的气密性能;而加入芳烃油可以提高硫化胶的分子链运动能力,但会引起物理性能和气密性能的下降,其综合效果不如添加甘油.     

Microstructure and thermal properties of ethylene‐(vinyl acetate) copolymer/rectorite nanocomposites

Ethylene‐(vinyl acetate) copolymer (EVA)/rectorite nanocomposites were prepared by direct melt extrusion of EVA and organo‐rectorite. The microstructures and thermal properties of EVA nanocomposites were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), solid‐state nuclear magnetic spectroscopy, positron annihilation spectroscopy, thermal gravimetric analysis (TGA) and dynamic mechanical analysis techniques. XRD pattern and SEM images show that the intercalated structure is formed and rectorite is finely dispersed in EVA matrix. When organoclay content of the hybrid increases to 7.5 wt%, or pristine rectorite was used instead of organoclay, the crystallization behavior of EVA nanocomposite changes greatly and the ratio of the monoclinic to orthorhombic crystal increases significantly. The relative fractional free volume of the nanocomposite decreases with the increasing organo‐rectorite content, and the values of damping factor (tan δ) for all nanocomposites are lower than that of pure EVA. These facts illuminate that intercalated structure restricts the segment motion and mobilization of polymer chain. TGA results of EVA nanocomposites in air indicate that deacylation of EVA is accelerated because of the catalytic effect and the thermal degradation of the main chain is delayed owing to the barrier effect of silicate layers. Copyright © 2005 Society of Chemical Industry     

Effect of sodium montmorillonite source on nylon 6/clay nanocomposites

The effect of sodium montmorillonite source on the morphology and properties of nylon 6 nanocomposites was examined using equivalent experimental conditions. Sodium montmorillonite samples acquired from two well-known mines, Yamagata, Japan, and Wyoming, USA, were ion exchanged with the same alkyl ammonium chloride compound. The resulting organoclays were extruded with a high molecular weight grade of nylon 6 under the same processing conditions. Quantitative analysis of TEM photomicrographs of the two nanocomposites reveal a slightly larger average particle length and a slightly higher degree of platelet exfoliation for the Yamagata based nanocomposite than the Wyoming version, thus, translating into a higher particle aspect ratio. The stress-strain behavior of the nanocomposites appears to reflect the nanocomposite morphology, in that higher stiffness and strengths are attainable with the increased particle aspect ratio. Moreover, the trends in stiffness behavior between the two types of nanocomposites may be explained by conventional composite theory.     

Reduction of the filler network interaction in novel inner liner compound based on SBR/rectorite nanocomposite by glycerin

The high cost of halogenated butyl rubber, traditional inner liner compound, has been an obstacle for the further development of tire industry. SBR/rectorite nanocompound was developed to reduce the cost, but it has relatively poor processability because of strong filler network interaction. In this work, SBR/rectorite nanocompound filled with 60 phr rectorite was prepared by latex compounding method, and glycerin was introduced to reduce the filler network interaction, besides, aromatic oil was added to further improve the processability. The addition of glycerin or aromatic oil could not change the microstructure of the nanocomposite. FTIR spectra indicated the hydrogen bond interaction between glycerin and rectorite layers. RPA analysis showed that the filler network interaction was reduced by adding glycerin or aromatic oil. With the addition of glycerin, the mechanical property of the nanocomposites was improved, along with the disappearance of delayed vulcanization, and the high gasbarrier property was maintained. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Influence of fillers on free volume and gas barrier properties in styrene-butadiene rubber studied by positrons

The measurements of free-volume hole property by positron annihilation lifetime spectroscopy (PALS) have been carried out for polymer-clay nanocomposite materials that consist of styrene-butadiene rubber (SBR) and layered silicate clay of rectorite and conventional composite materials N326 (carbon black) /SBR. The PALS and differential scanning calorimeter (DSC) results show layered rectorite has a stronger effect on restraining polymer chain mobility which results in the decrease of fraction free volume and gas permeation than carbon black. The dispersion of nanoscale rectorite clay in SBR largely enhances gas barrier property in contrast to results obtained in N326/SBR system. Experimental results reveal that gas permeability in rectorite/SBR nanocomposite is mainly influenced by fractional free volume and tortuous diffusional path effects attributed to the clay plateletlike morphology.     

轮胎内胎及内衬层用弹性体的研究进展

综述了轮胎内胎及内衬层用弹性体的发展进程,从最早使用的天然橡胶、丁苯橡胶到气密性优异的丁基橡胶、卤化丁基橡胶和DVA树脂,重点介绍了性能优异的新型纳米复合材料。采用纳米复合材料是内胎和内衬层技术的最新发展趋势,它能极大地提高内胎及内衬层的气密性,进而显著地提高轮胎的耐久性和使用寿命。