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。     

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。     

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。     

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。     

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。     

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.     

硫化方法对橡胶/黏土纳米复合材料黏土片层分散状态的影响

通过熔体插层法以及常压硫化法制备了橡胶/黏土纳米复合材料,并与模压硫化法制备的复合材料进行了对比,研究了硫化方法对橡胶/黏土纳米复合材料微观分散状态的影响。结果表明:采用熔体插层法制备的橡胶/黏土混合物,其受限状态的橡胶大分子链在高温、高压条件下,在黏土片层之间处于一种热力学不稳定状态;模压处理会对橡胶/黏土混合物的分散状态产生不利影响。透射电子显微镜和X光衍射分析表明,采用模压硫化、常压硫化得到的丁基橡胶或丁苯橡胶/黏土纳米复合材料中黏土片层的微观分散状态不同;排除压力的影响,常压硫化有利于提高橡胶/黏土纳米复合材料中黏土片层的分散程度。     

Polyamide 6/clay nanocomposites using a cointercalation organophilic clay via melt compounding

Polyamide 6/clay nanocomposites (PA6CN) were prepared via the melt compounding method by using a new kind of organophilic clay, which was obtained through cointercalation of epoxy resin and quaternary ammonium into Na‐montmorillonite. The dispersion effect of this kind of organophilic clay in the matrix was studied by means of X‐ray diffraction (XRD) and transmission electron microscopy (TEM); the silicate layers were dispersed homogeneously and nearly exfoliated in the matrix. This was probably the result of the strong interaction between epoxy groups and amide end groups of PA6. The mechanical properties and heat distortion temperature (HDT) of PA6CN increased dramatically. The notched Izod impact strength of PA6CN was 80% higher than that of PA6 when the clay loading was 5 wt %. Even at 10 wt % clay content, the impact strength was still higher than that of PA6. The finely dispersed silicate layers and the strong interaction between silicate layers and matrix decreased the water absorption. At 10 wt % clay content, PA6CN only absorbs half the amount of water compared with PA6. The dynamic mechanical properties of PA6CN were also studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 953–958, 2003     

黏土/SBR纳米复合材料的加工性能

采用橡胶加工分析仪(RPA)和孟山都毛细管流变仪研究了黏土／SBR纳米复合材料的Payne效应和流变性能。并同炭黑(N330)与微米级黏土橡胶复合材料进行了对比。结果表明，黏土／SBR纳米复合材料的流变规律与传统填充体系的流变规律类似，其弹性模量均随着填料用量的增加而增大，填料之间形成拟网络结构，在加工过程中，具有Payne效应；纳米分散的黏土具有更大的宽厚比和各向异性，对橡胶分子链限制作用更强。网构化程度更高，在相同的应变和频率下，与炭黑和黏土直接混炼填充SBR体系相比，黏土／SBR纳米复合材料的弹性模量更高；纳米化程度越高，网构化程度也越高；在相同的毛细管剪切速率下，黏土／SBR纳米复合胶料的黏度略高于炭黑体系；在黏土／SBR纳米复合胶料中，加入界面剂改善界面强度和改进工艺增加增强单元数目，胶料弹性模量提高；黏土／SBR纳米复合胶料具有出口膨胀小．吃粉快。挺性好的良好加工性能。     

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。     

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。     

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%。     

橡胶纳米复合材料研究进展

橡胶纳米复合材料因其优异的性能而目前材料科学研究的热点。本文论述了橡胶／粘土、橡胶／纳米SiO2、氢化NBR／丙烯酸金属盐、橡胶／纳米炭黑和白炭黑、橡胶／纳米纤维等橡胶基纳米复合材料的制备方法、机理、力学性能、工业应用领域等,讨论了层状硅酸盐粘土的表面修饰,提出了插层剂的选择原则,评价了各种合成技术的优缺点及工业价值,提出了橡胶纳米复合材料的发展趋势。     

Studies on nylon 6/clay nanocomposites by melt‐intercalation process

The preparation of nylon 6/clay nanocomposites by a melt‐intercalation process is proposed. X‐ray diffraction and DSC results show that the crystal structure and crystallization behaviors of the nanocomposites are different from those of nylon 6. Mechanical and thermal testing shows that the properties of the nanocomposites are superior to nylon 6 in terms of the heat‐distortion temperature, strength, and modulus without sacrificing their impact strength. This is due to the nanoscale effects and the strong interaction between the nylon 6 matrix and the clay interface, as revealed by X‐ray diffraction, transmission electron microscopy, and Molau testing. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1133–1138, 1999     

Synthesis and material properties of syndiotactic polystyrene/organophilic clay nanocomposites

Syndiotactic polystyrene (sPS)/organophilic clay nanocomposites were fabricated by direct‐melt intercalation method. To overcome the thermal instability of organophilic clay at high‐melt processing temperatures of sPS, an organophilic clay modified by alkyl phosphonium was adopted, which is known to be thermally stable. By using the newly synthesized clay, we could fabricate sPS intercalated nanocomposites. The microstructures of nanocomposites were confirmed by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The crystallization rate of nanocomposites investigated by differential scanning calorimetry (DSC) does not increase despite the presence of clay, which may be due to the physical hindrance of organic modifiers in the clay dispersion. Nanocomposites exhibited enhanced mechanical properties such as strength and stiffness relative to the virgin polymer. In addition, thermal stability was confirmed to be improved by thermogravimetric analysis (TGA). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2144–2150, 2004     

高性能丁基橡胶/有机黏土纳米复合材料的新型制备方法

采用一种新型制备方法--预膨胀有机黏土与机械共混的方法制备丁基橡胶（IIR）/有机黏土纳米复合材料。实验结果表明,当有机黏土为10 phr时,采用预膨胀有机黏土（S-OC）与机械共混的方法制备的IIR/有机黏土纳米复合材料（IIR/S-OCNs）的拉伸强度和撕裂强度,明显优于采用熔体法制备的IIR/有机黏土（OC）纳米复合材料（IIR/OCNs）的相应性能,较纯丁基橡胶分别提高了4.96倍、0.22倍;当有机黏土为5 phr时,采用预膨胀有机黏土与机械共混的方法制备的IIR/S-OC纳米复合材料的气体渗透率,分别较纯IIR、熔体法制备的IIR/OC纳米复合材料下降了21.88%和12.50%。这种新型制备方法是将溶液制备方法的优点与熔体制备方法的优点有机地统一在了一起。该材料有可能在高级无内胎轮胎气密层以及其他要求高性能弹性体材料的领域获得应用。     

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.     

Polymorphism in polyamide 66/clay nanocomposites

Polyamide 66/clay nanocomposites (PA66CN) were prepared via melt compounding method by using a new kind of organophilic clay, which was obtained through co-intercalation of epoxy resin and quaternary ammonium into Na-montmorillonite. The silicate layers were dispersed homogeneously and nearly exfoliated in polyamide 66 (PA66) matrix. The introduction of silicate layers induced the appearance of the γ phase in PA66CN at room temperature, more clay loadings would amplify this phenomenon; the addition of clay also changed the structure of the α crystalline phase. The presence of silicate layers increased the crystallization rate and had a strong hetero phase nucleation effect on PA66 matrix. The lower Brill transition temperature of PA66CN can be attributed to the strong interaction between polyamide chains and surfaces of silicate layers.     

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     

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