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/丁吡橡胶纳米复合材料的结构与性能研究

采用乳液共沉法制备粘土/丁吡橡胶纳米复合材料,并对其结构和性能进行研究。结果表明:粘土/丁吡橡胶纳米复合材料的整体分散效果较好,粘土用量对纳米复合材料的类型有影响;随着粘土用量的增大,粘土/丁吡橡胶混炼胶和硫化胶的储能模量逐渐增大,硫化胶的损耗因子随应变的增大而增大,邵尔A型硬度和100%定伸应力逐渐增大,气密性能提高;当粘土用量为20份时,复合材料的拉伸性能最佳。     

丁腈橡胶/层板剥离水滑石纳米复合材料的制备及性能

在辛烷/N-月桂酰基谷氨酸钠(LG)/水微乳液中制备了层板剥离水滑石(LDH-LG),然后采用共混法制备了丁腈橡胶(NBR)/LDH-LG纳米复合材料,研究了纳米复合材料的微观结构、硫化特性和拉伸性能。结果表明,LDH-LG在NBR基体中具有良好的分散性;当LDH-LG用量为3.0份时,NBR/LDH-LG纳米复合材料的结晶度、硫化速率指数和拉伸强度出现最大值,其中,硫化速率指数是纯NBR的5.4倍,拉伸强度较纯NBR提高了30.8%。     

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。     

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%。     

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／橡胶纳米复合材料实现工业生产

北京化工大学发明的具有我国自主知识产权的千吨级黏土／橡胶纳米复合材料率先实现工业生产。其产品中的纳米分散黏土可以部分或全部替代炭黑，从而可减轻橡胶加工行业对石油和天然气资源的依赖程度，并能提高橡胶制品的气密性和耐疲劳性，延长制品的使用寿命。专家认为，该技术具有原创性，达到国际领先水平。     

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。     

无机黏土制备剥离型三元乙丙橡胶/黏土纳米复合材料的新方法

先采用喷雾干燥工艺制得无机黏土／超细全硫化粉末丁腈橡胶的共混粉末,再用熔体共混工艺制备了三元乙丙橡胶／黏土纳米复合材料,研究了其微观分散形态。结果表明,采用喷雾干燥工艺并利用超细全硫化胶乳的结构特点,可使未经有机改性的无机黏土以剥离型结构纳米分散在三元乙丙橡胶基体中。     

SBS/黏土纳米复合材料的制备方法探究

探索了SBS／黏土纳米复合材料的制备工艺，将经过特殊有机化剂有机化的有机土按4％添加量改性SBS橡胶，采用先高速剪切再超声波处理工艺，能有效地提高SBS的性能。     

Preparation and characterization of exfoliated layered double hydroxide/silicone rubber nanocomposites

Silicone rubber (SR)/Mg–Al layered double hydroxide (LDH) nanocomposites were prepared by the solution intercalation of SR crosslinked by a platinum‐catalyzed hydrosilylation reaction into the galleries of dodecyl sulfate intercalated layered double hydroxide (DS–LDH). X‐ray diffraction and transmission electron microscopy analysis showed the formation of exfoliated structures of organomodified LDH layers in the SR matrix. The tensile strength and elongation at break of SR/DS–LDH (5 wt %) were maximally improved by 53 and 38%, respectively, in comparison with those of the neat polymer. Thermogravimetric analysis indicated that the thermal degradation temperature of the exfoliated SR/DS–LDH (1 wt %) nanocomposites at 50% weight loss was 20°C higher than that of pure SR. Differential scanning calorimetry analysis data confirmed that the melting temperature of the nanocomposites increased at lower filler loadings (1, 3, and 5 wt %), whereas it decreased at a higher filler loading (8 wt %). The relative improvements in the solvent‐uptake resistance behavior of the SR/DS–LDH nanocomposites were also observed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

丁腈橡胶/聚酰胺热塑性硫化胶的制备

用橡塑预混法、二步法和母炼胶法制备了丁腈橡胶／聚酰胺热塑性硫化胶(NBR／PATPV),研究了3种工艺对NBR／PATPV相态结构、流变性能、物理机械性能和耐溶剂性能的影响。结果表明,NBR与PA在高温、高剪切作用下,两相界面之间可发生微化学反应,但并不影响动态硫化时两相之间的相态反转过程。用橡塑预混法可制得分散相粒径小且分布均匀的TPV,该TPV的100％定伸应力大,压缩永久变形小,耐溶剂性能不佳,表观黏度略大,但挤出物外观光滑。     

动态硫化丁腈橡胶/二元共聚氯醚共混胶的制备与性能

采用动态硫化法制备了丁腈橡胶(NBR)／二元共聚氯醚(ECO)共混胶,研究了动态硫化温度、时间及不同丙烯腈含量的NBR对动态硫化胶性能的影响,对比了动态硫化胶和常规共混胶在性能上的差异。结果表明,当动态硫化温度为150℃．动态硫化时间为NBR的正硫化时间时,NBR／ECO共混胶中内聚能密度大的ECO为连续相。与常规共混胶相比,动态硫化胶具有低压缩永久变形及良好的力学性能、耐老化性能和耐油性能。     

氢化丁腈橡胶的制备

对国内外丁腈橡胶加氢方法作了较为详尽的评述,指出了各方法的优点,并对制备氢化丁腈橡胶的研究方向作了展望。     

Preparation and characterization of exfoliated graphite and its styrene butadiene rubber nanocomposites

Nanocomposites consisting of styrene butadiene rubber (SBR) reinforced with the modified-graphite and natural-graphite with concentrations of 5 wt% were fabricated. Processing techniques such as acid treatment, thermal shock, sonication were employed in the fabrication of modified-graphite.The graphite platelets oxidized using sulfuric and nitric acids were analyzed by the Raman scattering, Fourier transformed infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The FT-IR results indicate the presence of acid groups in the treated samples, and Raman spectroscopy of acid-graphite platelets further corroborate the formation of surface defect due to the introduction of functional groups. However, the structure of XRD peaks did not change irrespective of processing techniques.The SBR-based nanocomposites were characterized using the scanning electron microscopy (SEM), rheometer, Instron tensile machine, thermal and electrical analyser.The results showed that nanocomposites onto acid-graphite platelets enhanced mechanical properties and fatigue properties of nanocomposites compared to those containing natural-graphite due to the increase in the interaction between the polymer and the modified-graphite. And the dynamic properties of nanocomposites had no influence according to the processing techniques. Also, thermal and electrical properties of nanocomposites using acid-graphite platelets were enhanced due to the broadened specific surface by the acid treatment.     

丁腈橡胶/聚酰胺热塑性弹性体的制备及性能

采用Haake密炼机工艺、开炼机工艺和开炼机预混-Haake密炼机工艺制备了丁腈橡胶（NBR）／聚酰胺（PA）热塑性硫化胶（TPV）,研究了NBR／PATPV的结晶结构及其性能。结果表明,采用开炼机预混-Haake密炼机工艺可制得相态结构均匀、分散相粒径较小、力学性能和耐溶剂性能较好的NBR／PATPV。在NBR／PATPV中,NBR可诱发PA结晶。PA连续相结晶结构分布的均匀性和相界面之间的相互作用是提高NBR／PATPV耐溶剂性能的主要因素。     

甲基丙烯酸钆/丁腈橡胶复合材料的制备及性能

采用重结晶法制备了甲基丙烯酸钆[Gd(MAA)3],然后分别以过氧化二异丙苯(DCP)和硫黄为硫化体系制备了Gd(MAA)3/丁腈橡胶(NBR)复合材料,表征了Gd(MAA)3粒子及其复合材料的相态结构,研究了复合材料的硫化特性、拉伸性能和X射线屏蔽性能。结果表明,Gd(MAA)3原生粒子结构规整性好,粒径小,粒径分布均匀,同时配体的不饱和双键具有反应活性;在DCP引发下发生原位反应的Gd(MAA)3粒子在橡胶基体中分散更好、粒径更小、与基体界面作用力更强;2种复合材料的X射线屏蔽性能相当,但以DCP为硫化剂制得的复合材料的拉伸性能有明显改善。     

Preparation and characteristics of nitrile rubber (NBR) nanocomposites based on organophilic layered clay

The effect of clay modification on organo‐montmorillonite/NBR nanocomposites has been studied. Organo‐montmorillonite/NBR nanocomposites were prepared through a melt intercalation process. NBR nanocomposites were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), dynamic mechanical thermal analysis (DMTA) and a universal testing machine (UTM). XRD showed that the basal spacing in the clay increased, which means that the NBR matrix was intercalated in the clay layer galleries. On TEM images, organo‐montmorillonite (MMT) particles were clearly observed, having been exfoliated into nanoscale layers of about 10–20 nm thickness from their original 40 µm particle size. These layers were uniformly dispersed in the NBR matrix. The DMTA test showed that for these nanocomposites the plateau modulus and glass transition temperature (T_g) increased with respect to the corresponding values of pure NBR (without clay). UTM test showed that the nanocomposites had superior mechanical properties, ie strength and modulus. These improved properties are due to the nanoscale effects and strong interactions between the NBR matrix and the clay interface. Copyright © 2003 Society of Chemical Industry