Preparation,structure, and properties of montmorillonite/cellulose II/natural rubber nanocomposites

In this work, sodium montmorillonite clay was added, as filler, to nanocomposites of natural rubber (NR) and cellulose II (regenerated cellulose) in amounts varying from 0 to 5 phr (per hundred resin). Natural rubber (NR)/cellulose II/montmorillonite nanocomposites were prepared by co‐coagulating NR latex, montmorillonite aqueous suspension and cellulose xanthate. The clay was previously exfoliated in water, and the resulting suspension was then added to the mixture of NR latex with cellulose xanthate. Morphological, rheometric, mechanical, and dynamic mechanical properties were evaluated, and an increase in these properties was observed upon the addition of cellulose and clay nanomaterials to the rubber matrix. The results show the advantage in using cellulose as a nanopolymer as well as MMT as nanofiller. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Acrylonitrile butadiene nanocomposites containing different clays by latex compounding method

Considering elastomers nanocomposites, most of the works are focused on natural rubber, styrene butadiene rubber and rubber blends, while few of them deal with nitrile butadiene rubber (NBR). This article presents the reinforcing effect of two raw sodic montmorillonites (Mts) and one organoclay on NBR matrix prepared by the latex compounding method. Raw Mts increase the mechanical properties of neat matrices. A pseudoplastic behavior is observed with the incorporation of clays into the NBR latex, indicating interactions between polymer chains and clay sheets, in agreement with the results of zeta potential analysis. X‐ray diffraction evaluates changes in the interlayer distance of the clay, indicating the NBR intercalation phenomenon in all cases. Matrices with different clay proportions present variations in the mechanical properties, depending if the aggregation phenomenon is promoted. Morphological analysis of clays and nanocomposites as well as thermal analysis were performed. The variation in mechanical properties after an aging process was studied, evaluating the effects on the tensile strength, ultimate strain and 300% modulus. POLYM. ENG. SCI., 59:736–744, 2019. © 2018 Society of Plastics Engineers     

A short review on rubber/clay nanocomposites with emphasis on mechanical properties

The invention of Nylon‐6/clay nanocomposites by the Toyota Research Group of Japan heralded a new chapter in the field of polymer composites. This article highlights the work done in the field of rubber/clay nanocomposites. The preparations of rubber/clay nanocomposites by solution blending, latex compounding, and melt intercalation are covered and a thorough discussion of the mechanical properties of the various rubber/clay nanocomposite systems is presented. Other properties such as barrier, dynamic mechanical behavior, and thermal properties are also discussed. Finally, the future trends in the rubber/clay nanocomposites are mentioned. POLYM. ENG. SCI., 47:1956–1974, 2007. © 2007 Society of Plastics Engineers     

用橡胶乳液-黏土水悬浮液共凝法制备的橡胶/黏土纳米复合材料的结构及其复合机理

研究了利用橡胶乳液-黏土水悬浮液共凝法制备的橡胶／黏土纳米复合材料的结构和复合机理。结果表明,在加入絮凝剂使橡胶乳液-黏土水悬浮液共凝聚的过程中,由于存在胶乳粒子对黏土片层的隔离作用与在混合液中分散的黏土单片层的重新聚集作用的竞争,因此,在絮凝物中,橡胶大分子将黏土片层隔离成纳米分散单元（包括单片层和多片层的聚集体）,在多片层的黏土聚集体层间没有橡胶大分子插入。采用该共凝法制备的橡胶／黏土纳米复合材料具有“隔离型”结构。     

Montmorillonite clay nanocomposites based on vinyl pyridine‐styrene‐butadiene terpolymer (VPR)/acrylonitrile‐butadiene rubber (NBR) blend

This study describes a novel route to synthesize vinyl pyridine‐styrene‐butadiene terpolymer rubber (VP rubber) montmorillonite clay nanocomposites by latex blending technique. The pyridine moiety of the VP rubber was modified with methyl iodide to form the pyridinium ion during latex blending. Cation exchange reaction of the pyridinium ion of the VP rubber latex with sodium montmorillonite occurred during latex stage mixing which helped to form VP rubber‐montmorillonite clay nanocomposites. Coagulation of the latex‐clay slurry produced nanocomposites master batch. The master batch was compounded with acrylonitrile butadiene rubber (NBR). Fourier Transform Infrared Spectroscopy (FTIR) confirmed the modification of the pyridine moiety of VP rubber. Wide angle X‐ray diffraction (WAXD), scanning electron microscopy‐energy dispersive X‐ray spectrophotometry (SEM‐EDS) and transmission electron microscopy (TEM) provided the evidences of formation of nanocomposite. Remarkable improvements in the mechanical properties were found by addition of small amount of modified clay. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Photo-vulcanization using thiol-ene chemistry: Film formation,morphology and network characteristics of UV crosslinked rubber latices

The photo-vulcanization with versatile thiol-ene chemistry represents an innovative approach to crosslink diene-rubber materials both in latex and in solid film state. In this work, the structure of elastomer-based thiol-ene networks and the morphology after film formation are studied in detail using electron microscopic techniques, atomic force microscopy and multiple-quantum solid-state NMR spectroscopy. Additionally, film formation properties and corresponding macroscopic properties of photo-vulcanized natural rubber (NR) latex and its synthetic counterpart, isoprene rubber (IR) latex, are determined in dependence on the curing procedure (pre- and post-vulcanization). The results reveal that thiol-ene cured elastomers comprise homogenously distributed crosslinks with a low amount of short chain defects. Whilst photochemically pre-cured NR latex particles provide coherent films, the film formation and mechanical properties of IR are strongly governed by the crosslink density of the latex particles. In film state, photo-vulcanization promotes narrow crosslink distributions and excellent tensile properties of both NR and IR.     

Cellulose-Nanofiber-Reinforced Rubber Composites with Resorcinol Resin Prepared by Elastic Kneading

A resorcinol resin/water dispersion and a rubber latex are added to 1% 2,2,6,6,-tetramethylpyperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TEMPO-CNFs) dispersed in water, followed by oven drying at 40 °C for 20 h to prepare a dried TEMPO-CNF/resorcinol resin/latex rubber (DTRL) mixture with a weight ratio of 1/0.5/3. DTRL is then added to a nitrile-butadiene rubber (NBR) or a carboxy group-containing NBR (X-NBR) sheet, and the mixture is kneaded by a two-roll mill at 20–30 °C with high shear forces. The tensile strength and Young's modulus of the crosslinked DTRL/rubber composite sheets remarkably increased from 10 and 12 MPa, respectively, for the reference sheet to 24 and 82 MPa, respectively, for the DTRL/rubber composite sheets containing ≈10 vol% TEMPO-CNFs. Scanning electron microscopy revealed that no TEMPO-CNF agglomerates are present in the DTRL/rubber composite sheets. The tensile properties of the composite sheets are the best when a X-NBR sheet and NBR latex are used as the matrix rubber and latex in DTRL preparation, respectively. When water-extracted DTRL (WDTRL, mass recovery ratio ≈94%) is used in place of DTRL, the WDTRL/rubber composite sheets show sufficient water resistance, while the tensile properties are almost the same as those of the DTRL/rubber composite sheets.     

Structure and properties of strain‐induced crystallization rubber–clay nanocomposites by co‐coagulating the rubber latex and clay aqueous suspension

Natural rubber (NR)–clay (clay is montmorillonite) and chloroprene rubber (CR)–clay nanocomposites were prepared by co‐coagulating the rubber latex and clay aqueous suspension. Transmission electron microscopy showed that the layers of clay were dispersed in the NR matrix at a nano level, and the aspect ratio (width/thickness) of the platelet inclusions was reduced and clay layers aligned more orderly during the compounding operation on an open mill. However, X‐ray diffraction indicated that there were some nonexfoliated clay layers in the NR matrix. Stress–strain curves showed that the moduli of NR were significantly improved with the increase of the amount of clay. At the same time, the clay layers inhibited the crystallization of NR on stretch, especially clay content of more than 10 phr. Compared with the carbon‐black‐filled NR composites, NR–clay nanocomposites exhibited high hardness, high modulus, high tear strength, and excellent antiaging and gas barrier properties. Similar to NR–clay nanocomposites, CR–clay nanocomposites also exhibited high hardness, high modulus, and high tear strength. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 318–323, 2005     

Morphology and mechanical properties of clay/styrene‐butadiene rubber nanocomposites

Based on the character of a clay that could be separated into many 1‐nm thickness monolayers, clay styrene‐butadiene rubber (SBR) nanocomposites were acquired by mixing the SBR latex with a clay/water dispersion and coagulating the mixture. The structure of the dispersion of clay in the SBR was studied through TEM. The mechanical properties of clay/SBR nanocomposites with different filling amounts of clay were studied. The results showed that the main structure of the dispersion of clay in the SBR was a layer bundle whose thickness was 4–10 nm and its aggregation formed by several or many layer bundles. Compared with the other filler, some mechanical properties of clay/SBR nanocomposites exceeded those of carbon black/SBR composites and they were higher than those of clay/SBR composites produced by directly mixing clay with SBR through regular rubber processing means. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1873–1878, 2000     

Synthesis and characterization of styrene butadiene rubber—Bentonite clay nanocomposites

In the present study, naturally occurring unfractionated bentonite clay was used to prepare styrene butadiene rubber/bentonite clay nanocomposite by latex stage blending. The bentonite clay was organo‐modified by in situ resol formation by the reaction of resorcinol and formaldehyde. The latex clay mixture was co‐coagulated with acid. The resulting clay masterbatch was compounded and evaluated by Fourier Transform Infrared spectroscopy, X‐ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X‐ray spectroscopy (EDS), Scanning Electron Microscopy, Thermogravimetric analysis, and Differential Scanning Calorimetry. XRD showed that the interplanar distance of the in situ resol‐modified bentonite clay increased from 1.23 to 1.41 nm for the unmodified bentonite. TEM analysis indicated partial exfoliation and/or intercalation. EDS (Si and Al mapping) of the clay revealed the nature of the dispersion in the nanocomposites vis‐à‐vis the conventional styrene‐butadiene rubber (SBR)/bentonite clay composite. Thermogravimetric analysis was used to compare the decomposition trends of the SBR/clay nanocomposites with the SBR/clay composite. The glass transition temperature of SBR/clay nanocomposites increased as compared with that of neat SBR. Substantial improvement in most of the other mechanical properties was also observed in case of the nanocomposites. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Process for preparing a nylon‐6/ clay/acrylate rubber nanocomposite with high toughness and stiffness

A novel nylon‐6/clay/acrylate rubber ternary nanocomposite has been prepared using a process developed by the authors. The process consists of two steps: firstly, an acrylate rubber/clay composite (ARCC) was manufactured by spray‐drying a mixture of clay slurry and irradiated acrylate rubber latex; secondly, the nylon‐6/unmodified clay/acrylate rubber ternary nanocomposite was prepared by blending ARCC and nylon‐6. It has been found that the acrylate rubber particles and clay platelets can help each other to disperse or exfoliate in the nylon‐6 matrix. The silicate layers without organic treatment are exfoliated with the aid of irradiated acrylate rubber particles and the irradiated acrylate rubber particles are uniformly dispersed in the matrix with the aid of clay platelets. The novel nanocomposite prepared using the new process shows simultaneously high impact strength, high flexural modulus and high heat distortion temperature. Copyright © 2007 Society of Chemical Industry     

Organic interfacial tailoring of styrene butadiene rubber–clay nanocomposites prepared by latex compounding method

The styrene butadiene rubber (SBR)–clay nanocompounds were prepared by the latex compounding method, and then hexadecyl trimethyl ammonium bromide (C16) and 3‐aminopropyl triethoxy silane (KH550) were added into these nanocompounds on a two‐roll mill to prepare nanocomposites with strong interfacial interaction. The structure and properties of SBR–clay nanocomposites were carefully studied by X‐ray diffraction (XRD) studies, transmission electron microscopy (TEM), Rubber Process Analyzer (RPA), and mechanical testing. Compared with unmodified nanocomposites, the dispersion structure of modified SBR–clay nanocomposites is better with part rubber‐intercalated or part modifier‐intercalated structure. The tensile strength and the modulus at 300% elongation of modified SBR–clay nanocomposites are higher than three times of those of unmodified nanocomposites, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1826–1833, 2007     

原位聚合法制备高透光率韧性PMMA复合树脂的研究

采用原位聚合法制备PMMA/P(BA-St)/PMMA三层韧性有机玻璃复合树脂,分子设计方法的使用,保持了材料的透明性。考察了韧性粒子粒径、橡胶相组成以及橡胶含量对材料力学和光学性能的影响。借助透射电镜、扫描电镜和动态光散射方法对复合胶乳粒子以及所制材料的形态结构进行了表征。结果表明:橡胶相的折光指数对材料的透光率有明显影响,橡胶相玻璃化温度越低,越有利于增韧。     

橡胶／粘土插层纳米复合材料的研究进展

综述了橡胶／粘土插层纳米复合材料的制备方法及性能特征。重点介绍了溶液插层法、乳液插层法和熔体插层法及相关研究进展。评价了各种制备技术的优缺点,提出了橡胶／粘土插层纳米复合材料的发展趋势。     

有机改性与乳液插层法相结合制备的丁苯橡胶/黏土纳米复合材料的结构与性能

针对现有的乳液插层法所制备的橡胶／黏土纳米复合材料中填料与橡胶之间界面结合较弱的缺点,在乳液插层法中对无机黏土进行有机改性,制备出力学性能优异的纳米复合材料。X射线衍射和透射电子显微镜技术分析表明,有机改性后的复合材料中黏土被部分地有机改性,且在基体中以纳米尺寸分散。     

工程轮胎胎面胶用黏土/炭黑/天然橡胶纳米复合材料的性能

在工程轮胎胎面胶配方中,用黏土替代部分高耐磨炭黑,利用机械共混工艺制备了黏土/炭黑/天然橡胶(NR)纳米复合材料,研究了复合材料的综合性能.结果表明,黏土的加入不会对胶料的硫化特性产生太大影响;少量黏土的加入增强了混炼胶的填料网络作用,改善了炭黑/NR硫化胶的物理机械性能,耐磨性能提高了15%～30%,降低了滚动阻力,提高了耐屈挠疲劳破坏性能,当黏土填充量为4份时,复合材料的综合性能最优.     

Ethylene–octene copolymer (engage)–clay nanocomposites: Preparation and characterization

In this work, preparation and properties of nanoclay modified by organic amine (octadecyl amine, a primary amine) and Engage (ethylene–octene copolymer)–clay nanocomposites are reported. The clay and rubber nanocomposites have been characterized with the help of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X‐ray diffraction (XRD). The X‐ray results suggest that the intergallery spacing of pristine clay increases with the incorporation of the amine. The XRD peak observed in the range of 3–10° for the modified clay also disappears in the rubber nanocomposites at low loading. TEM photographs show exfoliation of the clays in the range of 10–30 nm in Engage. In the FTIR spectra of the nanocomposite, there are common peaks for the virgin rubber as well as those for the clay. Excellent improvement in mechanical properties, like tensile strength, elongation at break, and modulus, is observed on incorporation of the nanoclay in Engage. The storage modulus increases, tan δ peak decreases, and the glass transition temperature is shifted to higher temperature. The results could be explained with the help of morphology, dispersion of the nanofiller, and its interaction with the rubber. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 603–610, 2006     

Styrene–butadiene rubber/cellulose II/clay nanocomposites prepared by cocoagulation—mechanical properties

In this work, nanocomposites of styrene butadiene rubber (SBR), cellulose II, and clay were prepared by cocoagulation of SBR latex, cellulose xanthate, and clay aqueous suspension mixtures. The incorporated amount of cellulose II was 15 phr, and the clay varied from 0 to 7 phr. The influence of cellulose II and clay was investigated by rheometric, mechanical, physicochemical, and morphological properties. From the analysis of transmission electron microscopy (TEM), dispersion in nanometric scale (below 100nm) of the cellulosic and mineral components throughout the elastomeric matrix was observed. XRD analysis suggested that fully exfoliated structure could be obtained by this method when low loading of silicate layers (up to 5 phr) is used. The results from mechanical tests showed that the nanocomposites presented better mechanical properties than SBR gum vulcanizate. Furthermore, 5 phr of clay is enough to achieve the best tensile properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

黏土/天然橡胶纳米复合材料的制备及性能

利用乳液插层法制备了黏土／天然橡胶纳米复合材料,研究了该复合材料的力学性能、应力应变行为、耐磨性、气体阻隔性和耐老化性能。结果表明,黏土／天然橡胶纳米复合材料与高耐磨炭黑(N330)、白炭黑增强橡胶相比,邵尔A型硬度、定伸应力和撕裂强度较高,拉伸强度相当。黏土、N330以及白炭黑对天然橡胶的拉伸结晶有影响,填料用量对材料拉伸强度的影响存在最佳值。黏土／天然橡胶纳米复合材料具有良好的耐磨性、气体阻隔性和耐老化性能。     

Bentonite as a reinforcing and compatibilizing filler for natural rubber and polystyrene blends in latex stage

Bentonite clay was used as a reinforcing and compatibilizing filler for natural rubber/polystyrene (NR/PS) blend via latex blending process. The reinforcing and compatibilizing performance of bentonite clay in the NR/PS blends were evaluated. The improvement of the mechanical properties of NR/PS blends with the weight ratios of 90/10, 80/20, and 70/30 was found with the addition of 3 and 5 parts per hundred rubber (phr) clay. The characterization by using Fourier transform infrared spectroscopy and X‐ray diffraction (XRD) gave the evidence that the silicate layer was intercalated by NR and PS molecular chains. The morphology of tensile fracture surface by scanning electron microscope showed the separated phase boundaries of PS and NR blend and gradual disappearance with the bentonite content. This could be implied that the bentonite contributes to the compatibilization between PS and NR. The compatibilization action of the bentonite clay was also reflected by the shift of glass transition temperature (T_g) of NR to higher temperatures than those of the blends. These results suggested that the tensile and tear properties of the blends were controlled by compatibility between NR and PS. The most enhanced properties of blends were found with the addition of 3 phr bentonite clay. POLYM. ENG. SCI., 54:1436–1443, 2014. © 2013 Society of Plastics Engineers