丁基橡胶/有机黏土纳米复合材料的结构和性能

采用溶液插层法制备了丁基橡胶／有机黏土纳米复合材料,并用透射电子显微镜和X射线衍射仪研究了该纳米复合材料的形态结构。结果表明,丁基橡胶／有机黏土纳米复合材料是插层型的纳米复合材料。与丁基橡胶相比,该纳米复合材料具有优异的力学性能和气体阻隔性能,并且这2种性能均随有机黏土用量的增加而增强。填料的形状会对该纳米复合材料的气体阻隔性能产生影响。     

Mechanical properties of gamma‐irradiated styrene‐butadiene rubber/acid‐treated vermiculite clay/maleic anhydride nanocomposites

Nanoparticle vermiculite (VMT) clay was prepared by treatment with hydrochloric acid. Styrene‐butadiene rubber (SBR) nanocomposites were prepared by mixing different contents (2.5, 5, 7.5, and 10 phr) of untreated (VMT) and acid‐treated (DVMT) vermiculite clay, respectively. In addition, different contents (3, 7, and 10 phr) of maleic anhydride (MA) as compatibilizer were mixed via direct melt compounding in internal mixer. The effect of gamma irradiation, VMT clay, and MA contents on the mechanical properties was studied. The acid‐treated VMT clay was characterized by x‐ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FT‐IR) spectroscopy. Meanwhile, the SBR/VMT composites, SBR/DVMT, and SBR/DVMT/MA nanocomposites were characterized via crosslinking density and tensile mechanical testing and FT‐IR spectroscopic analysis. The results indicated that good yield of nanoparticle vermiculite was achieved when the acid treatment was carried out for 120 h. In addition, the results showed that the presence of DVMT clay improved the chemical bonding in the SBR nanocomposites and hence their mechanical properties. The highest improvement was obtained when the contents of DVMT clay, MA, and irradiation dose were 10 phr, 3 phr, and 100 kGy, respectively. POLYM. ENG. SCI., 59:355–364, 2019. © 2018 Society of Plastics Engineers     

复配改性黏土/丁腈橡胶纳米复合材料的结构及性能

用不同阴离子表面活性剂十二烷基磺酸钠(SDS)和十二烷基苯磺酸钠(SDBS)与阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)复配改性无机黏土,制备了有机改性黏土/丁腈橡胶(NBR)纳米复合材料,并表征了有机黏土与纳米复合材料,考察了不同表面活性剂及配比对纳米复合材料物理机械性能的影响。结果表明,CTAB/SDS复配改性黏土/NBR纳米复合材料的层间距比CTAB改性黏土/NBR纳米复合材料增加了1.15 nm,具有更多的插层结构,橡胶基体中黏土颗粒分布细致、均匀,且黏土片层间无聚集体存在;CTAB/SDS复配改性黏土/NBR纳米复合材料的物理机械性能优于CTAB/SDBS复配改性黏土/NBR纳米复合材料及CTAB改性黏土/NBR纳米复合材料,且当CTAB/SDS(质量比)为4∶2时,纳米复合材料的拉伸强度、撕裂强度及扯断伸长率出现最大值,其中,拉伸强度和撕裂强度较CTAB改性黏土/NBR纳米复合材料分别提高了62.7%和12.3%。     

Mechanical and thermal properties of gamma irradiated ethylene propylene diene monomer rubber/vermiculite clay/maleic anhydride composites

Vermiculite clay (VMT) was first treated with 2 M of hydrochloric acid. The VMT, before and after acid‐treatment, was characterized by X‐ray diffraction (XRD) and transmission electron microscopy. The untreated (VMT) and acid‐treated vermiculite clay DVMT) at different contents (2.5–10 phr) and maleic anhydride (MA) at different contents (3–10 phr) were mixed with ethylene polyethylene diene rubber (EPDM) via direct melt compounding in an internal mixer. The mechanical and thermal properties of gamma irradiated composites were studied. The results indicated that the physical properties of gamma irradiated EPDM/DVMT/MA nanocomposites were greatly improved after loading with either DVMT or MA. The improvement was achieved when the content of DVMT clay was 5 phr, MA 7 phr and irradiation dose at 75 kGy. J. VINYL ADDIT. TECHNOL., 25:E3–E11, 2019. © 2018 Society of Plastics Engineers     

Influence of sepiolite and electron beam irradiation on the structural and physicochemical properties of polyethylene/starch nanocomposites

This study presents the influence of functionalized sepiolite and electron beam irradiation on the structural and physicochemical properties of high density polyethylene (HDPE)/starch blends. HDPE/Starch blends containing varying amounts of sepiolite [from 2 to 6 parts per hundred (phr) resins] were prepared in an internal mixer and subjected to electron beam irradiation. The structural analysis of nanocomposites revealed an interaction among the incorporated components. The morphological analysis depicted the void‐free dispersion of additives in the nanocomposites as well as an improvement in the compatibility between the matrix and additives. The sepiolite served as a heat barrier and improved the thermal stability of blend upto a maximum of 45°C. The ultimate tensile strength and Young's modulus (E) of blend was slightly improved with the incorporation of sepiolite and radiation. On the contrary, the E of nanocomposites was significantly improved with radiation dose. The sample containing 6 phr sepiolite and irradiated at 100 kGy showed 61% increase in E when compared with its unirradiated counterpart. Likewise, the thermal distortion temperature and Vicat softening temperature of the blend was slightly changed with the incorporation of sepiolite and radiation dose; however, increased with radiation dose in the nanocomposites. The improvements in the properties of nanocomposites with radiation dose were assigned to the formation of radiation‐induced crosslinked network as revealed by gel content analysis. The results presented here revealed substantial improvements in the properties of nanocomposites with irradiation, which pave way for their potential applications in various sectors including packaging materials for radiation sterilizable products. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

粘土橡胶纳米复合材料研究进展

简要概述了粘土的有机改性机理、橡胶/粘土纳米复合材料的制备方法、结构与表征和橡胶/粘土纳米复合材料的研究进展.     

Fibre reinforced nanocomposites: Mechanical properties of PA6/clay and glass fibre/PA6/clay nanocomposites

In this paper, the effect of two different reinforcements: clay at the nanoscale and glass fibres at the micro-scale, on the mechanical properties of PA/clay and GF/PA/clay are studied. The Halpin-Tsai model is used to predict the modulus of PA/Clay and GF/PA/Clay, both of which are influenced by two factors: reinforcement shape and volume fraction. The relationships between the modulus and reinforcement shape and volume fraction are discussed. Tensile modulus, measured in tensile tests is used to fit the Halpin-Tsai models. The results demonstrate a synergy between the reinforcements at the two different scales.     

Mechanical properties development of high-ACN nitrile-butadiene rubber/organoclay nanocomposites

The nanocomposites of nitrile-butadiene rubber (NBR) with high acrylonitrile content and Cloisite 30B were prepared in the presence of the resorcinol and hexamethylenetetramine (RH) complex as a compatibiliser. The structure of the NBR nanocomposites was characterised by cure characteristics, XRD, TEM and mechanical properties. The mechanical properties of the nanocomposites containing RH were far superior to those of NBR nanocomposites alone. Some hyperelastic models were approved on comparative study of tensile properties and the effect of RH compatibiliser on the material parameters of the models was investigated. The Mori–Tanaka and Halpin–Tsai models were used to estimate the modulus of prepared nanocomposites and compared with experimental results. The effect of RH on the intercalation/exfoliation of silicate layers was investigated from combination of effective particle method and Mori–Tanaka theory. This technique showed that the average number of silicate layers in each effective particle can decrease with RH compatibiliser.     

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     

熔体法制备有机黏土/橡胶纳米复合材料的结构及性能

将有机黏土(OC)分别加入到天然橡胶(NR)、丁苯橡胶(SBR)、丁基橡胶(IIR)和三元乙丙橡胶(EPDM)中,通过熔体法制备了纳米复合材料。探讨了橡胶黏度及其分子结构对OC在复合材料中分散状况的影响,研究了复合材料的力学性能。结果表明,在以NR为基体的复合材料中。OC片层分散均匀,且剥离程度较高;在SBR,IIR,EPDM中,OC以插层结构为主,且插层效果从大到小的顺序依次为SBR,IIR,EPDM。与相应的纯胶相比,OC／NR纳米复合材料的定伸应力提高,拉伸强度和扯断伸长率有所下降;OC／SBR,OC／IIR,OC／EPDM纳米复合材料的定伸应力变化不大,拉伸强度和扯断伸长率明显提高,且OC／SBR和OC／EPDM复合材料的撕裂强度提高。     

Transport properties of natural rubber latex layered clay nanocomposites

Natural rubber latex layered clay nanocomposites were prepared with low loadings of nanoclay using conventional compounding technique. A higher loading of clay resulted in processing difficulties due to viscosity build up. X‐ray analysis showed that nanocomposites in which layered silicate layers were either delaminated or ordered as in an intercalated structure was obtained. Partially exfoliated structure was observed from TEM photographs of nanocomposites with 3 phr nanoclay. The transport properties, sorption, diffusion, and permeation coefficients were measured using the solvent toluene at 303 K. A higher decrease for the diffusion coefficient for nanocomposites directs the presence of tortuous path for the diffusing molecules. Thermodynamic parameters show a better compatibility for the silicates with rubber resulted in the formation of an elastomeric network. Gas permeability results of the nanocomposites suggest a better barrier resistancefor oxygen molecules even in lower loading of nanoclay and different gas transport models (Nielsen, Bharadwaj, Cussler) were applied to describe the behavior of these nanocomposites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mechanical and thermal properties of modified kaolin clay/unsaturated polyester nanocomposites

The improvement in thermal and mechanical properties of Nanocomposites prepared with unsaturated polyester (UP) as polymer matrix and various loadings of amino‐modified nano kaolinite clay as filler has been studied. Mechanical stirring and ultrasonication resulted in better dispersion of the clay. For curing polyester resin, cobalt naphthenate was used as accelerator and MEKP as initiator. Dynamic Mechanical Analysis (DMA) was carried out to find storage and loss modulus. Thermal stability was found through thermogravimetric analysis and the evaluation of structure and morphology of the nanocomposites were done through XRD, SEM, and TEM. Nanocomposite with 3 phr of amino modified clay has shown higher storage modulus and an improved thermal stability of UP/clay nanocomposites has been established. Tensile strength and toughness of the composite have been found to achieve maximum values at 1 phr of clay and the storage modulus has had an improvement of 38% compared to neat UPR. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43245.     

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。     

Mechanical, electrical, and thermal properties of irradiated low-density polyethylene by electron beam

The effect of electron-beam (EB) irradiation on the mechanical, electrical, and thermal properties of low-density polyethylene (LDPE) was studied The LDPE was irradiated by using 3?MeV EB machine at doses ranging from 25 to 250?kGy in air at room temperature and analyzed for mechanical, thermal, and electrical properties. It was revealed by differential scanning calorimetry analysis that the crystallinity of the EB-radiated LDPE decreased slightly as verified by a marginal reduction in the densities, enthalpy, and melting points. Thermogravimetric analysis test showed that the thermal degradation of LDPE improved by increasing irradiation. The results obtained from both gel content and hot set tests, indicating whether the applicable LDPE has been properly cross-linked or not, showed that under the EB irradiation conditions employed, the cross-linking of the LDPE samples occur mainly in the amorphous region, and the cross-linking density at each irradiation dose depends almost on the amorphous portions of the LDPE. A significant improvement in the tensile strength of the neat LDPE samples was obtained upon EB up to 250?kGy with a concomitant decline in elongation at break. The results on the electrical properties revealed that the surface resistance, volume resistivity, and dielectric strength of the LDPE increase with irradiation dose and reaches a maximum at a 250?kGy irradiation dose. No considerable change of breakdown voltage, dielectric constant, and dielectric loss factor were observed with increasing irradiation dose. The enhancement in the heat deformation, hardness, and thermal aging properties of LDPE upon EB irradiation, suggests that irradiated LDPE is more thermally and mechanically stable than virgin LDPE.     

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。     

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     

炭黑/黏土/丁苯橡胶纳米复合材料的性能

研究了用1份(质量,下同)或2份黏土替代5份或10份炭黑对炭黑/黏土/丁苯橡胶纳米复合材料性能的影响。结果表明,用少量黏土非等量替代炭黑后,复合材料的物理机械性能变化不大;复合材料的耐磨性能随炭黑用量的减少而降低,耐屈挠疲劳性能随黏土用量增加而提高。当炭黑与黏土的填充量分别为45份和2份时,复合材料的物理机械性能和动态生热与填充50份炭黑时相当。     

高性能橡胶/黏土纳米复合材料的制备与结构

研究了硬脂酸(SA)处理有机黏土(OC)制备橡胶/黏土纳米复合材料的结构与性能,并与未处理的OC制备的纳米复合材料进行了对比。结果表明,SA上的—COOH与OC片层表面的—OH发生了酯化反应,促使SA插层进入OC层间,使层间距扩大。采用SA处理OC制备出分散相态细致均匀、力学性能优异的丁腈橡胶/黏土(NBR/SA-OC)纳米复合材料;当OC与SA的质量比为10∶6时,纳米复合材料的性能最优。用带有极性和反应官能团的橡胶制备橡胶/黏土纳米复合材料,OC的分散性更好,与未处理的OC制备的纳米复合材料相比力学性能更优。     

Mechanical properties of polypropylene/clay nanocomposites: Effect of clay content,polymer/clay compatibility,and processing conditions

In this work, polypropylene/clay nanocomposites with 0.5, 1, 3, and 5 wt % of montmorillonite (MMT) (unmodified clay) were prepared by intensive mixing at 50 rpm and 10 min of mixing. For the highest clay content (5 wt %), the initial materials or the processing conditions were changed to study their independent effect. On one hand, 10 wt % of PP‐graft‐MA (PP‐g‐MA) was incorporated or MMT was replaced by organomodified clays (C10A and C30B). On the other side, for the initial system, the speed of rotation (100 and 150 rpm) and the mixing time (5 and 15 min) were altered. In all cases, the state of the clay inside the matrix (DRX), the degree of dispersion in the micro (SEM) and nano (TEM) scales, and the rheological and mechanical properties were analyzed. It was found that the stiffness increased with clay content, whereas tensile and impact strength did not significantly change. Although intercalated structures were observed in the composites with unmodified clay, in the composites with modified clay or PP‐g‐MA, improved dispersion of clay in PP was found. The mechanical properties increased accordingly. The degree of dispersion of the filler in the matrix appeared to be unaffected by the changes in the processing conditions introduced. Finally, the elastic modulus was modeled by using an effective filler‐parameter model based on Halpin–Tsai equations, which also allowed estimating the relative degree of dispersion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Mechanical properties and structures of dicyanate–clay nanocomposites

Dicyanate–clay nanocomposites comprising a dicyanate resin and a type of organically modified clay were prepared and characterized, and their thermomechanical properties were investigated. The organically modified clay had silicate layers of nanometer size intercalated with an organic modifier, which improved the compatibility between the clay and organic materials, such as dicyanate resins. Dynamic mechanical analysis was performed to investigate the thermomechanical properties of the dicyanate–clay nanocomposites containing various amounts of the clay. The storage modulus of the nanocomposites below their glass‐transition temperatures slightly increased with increasing clay content. The glass‐transition temperature of the dicyanate–clay nanocomposites increased with increasing clay content. The nanostructures of the dicyanate–clay nanocomposites were characterized by transmission electron microscopy and X‐ray diffraction analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2629–2633, 2003