偶联剂KH-792对淀粉／SBR复合材料结构和性能的影响

使用氨基硅烷偶联剂KH-792制备了淀粉／SBR复合材料，对比考察了2种工艺中KH-792的不同用量对材料硫化性能、力学性能和微观相态结构的影响。结果表明，KH-792应用工艺的不同使得其反应性发生变化，突出体现于材料硫化性能的差异，但2种应用工艺下KH-792能在一定程度上提高复合材料的力学性能：在工艺Ⅰ中，能有效提高复合材料的定伸应力；在工艺Ⅱ中，能够赋予复合材料更加优异的拉伸强度和撕裂强度。SEM显示，工艺Ⅱ中填料在橡胶基体中的分散更为精细，界面结合更好。     

碳纳米管/天然橡胶复合材料的结构与性能

通过机械混炼法制备了碳纳米管(CNT)／天然橡胶(NR)复合材料,研究了CNT的预处理方式对复合材料结构与性能的影响。结果表明,与NR相比,CNT／NR复合材料的硫化返原现象减轻,硫化后凝胶质量分数降低,硫化剂用量应适当增加,由混酸氧化处理的CNT填充橡胶复合材料的硫化迟滞效应明显;复合材料内部存在CNT的富集区域和CNT含量很少的橡胶区域,CNT与NR之间的界面结合作用不好;由HF处理的CNT填充橡胶复合材料的整体性能最好,但受CNT在橡胶基体中的不良分散状态及界面性质的影响,其力学性能不高。     

无规溶聚戊苯橡胶的合成及其阻尼性能

以环己烷为溶剂,正丁基锂（简称Li）为引发剂,四氢呋喃（THF）为结构调节剂,四氯化锡为偶联剂,采用负离子溶液聚合法制备了不同微观结构的无规溶聚戊苯橡胶（SSIR）,并对其结构和性能进行了表征。结果表明,调节剂的用量、苯乙烯含量以及相对分子质量对SSIR的结构和性能有明显影响,随着THF/Li（摩尔比）的增大,SSIR的3,4-异戊二烯（Ip）结构含量明显增大,而1,2-Ip结构含量略有增加;SSIR的玻璃化转变温度、损耗因子随烯类侧基含量的增大和苯乙烯含量的增大而增大;SSIR分子链段中的烯类侧基质量分数为32.2%、苯乙烯质量分数为32.1%时,最大损耗因子可达1.10,与溶聚丁苯橡胶相比,所合成的SSIR具有良好的力学性能和更好的阻尼性能。     

过氧化物硫化聚醚型聚氨酯混炼橡胶力学性能的研究

研究了过氧化物过氧化二异丙苯（DCP）、双叔丁基过氧化异丙基苯（BIPB）和补强剂（炭黑或白炭黑）对聚醚型聚氨酯混炼橡胶力学性能的影响,讨论了DCP和补强剂用量变化及不同硫化条件对混炼橡胶力学性能的影响。结果表明,DCP硫化混炼胶定伸应力高,永久变形小;BIPB硫化混炼胶硬度和强度高;当DCP用量在1．6份时,混炼胶拉伸强度和撕裂强度最高;提高补强剂用量,混炼胶硬度和定伸应力增加,拉伸强度变化不明显,但永久变形变大。     

两种补强填料对氟醚橡胶性能的影响

设计补强填料（炭黑N990/硫酸钡）用量和并用比不同的9个试验配方,研究炭黑N990/硫酸钡用量和并用比对氟醚橡胶胶料硫化特性、耐低温性能、物理性能、耐热空气老化性能、耐介质性能和压缩永久变形的影响。结果表明：炭黑N990/硫酸钡用量和并用比对氟醚橡胶硫化胶性能影响较大;随着炭黑N990/硫酸钡用量的增大,氟醚橡胶硫化胶的力学性能更好;氟醚橡胶硫化胶的耐低温性能主要由橡胶的分子结构决定,同时含胶率越高,硫化胶的耐低温性能越好;氟醚橡胶硫化胶的耐介质性能与其交联程度有关,当炭黑N990/硫酸钡用量增大时,橡胶与其形成的交联网络更加密集,硫化胶的耐介质性能提高。     

填料对乙烯-醋酸乙烯酯橡胶发泡材料性能的影响

使用无转子发泡硫化仪、RPA橡胶分析仪、体视显微镜以及力学性能测试仪器等研究了白炭黑和炭黑对乙烯-醋酸乙烯酯橡胶(EVM)硫化发泡特性、发泡材料微观结构和性能的影响。结果表明,白炭黑用量较少时,体系焦烧时间和正硫化时间均延长,发泡剂分解速度提高。与相同用量的白炭黑体系相比,炭黑体系不易焦烧,正硫化时间较长,发泡剂分解速度较快。白炭黑体系泡孔质量好于炭黑体系,其中添加30份白炭黑的泡沫材料具有最低密度。RPA分析结果表明,减少白炭黑用量或采用炭黑作填料均能降低体系储能模量(G′)和损耗模量(G″),炭黑体系泡沫材料动态模量具有较强温度敏感性。     

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。     

交联剂用量对BR/EVA热塑性硫化胶性能的影响

采用动态硫化法制备了BR/EVA热塑性硫化胶(TPV),考查了硫化体系中硫黄用量对混炼胶的硫化行为、静态硫化胶的溶出物含量及性能的影响,并对BR/EVA型TPV的力学性能及微观结构进行了研究。结果表明,随着硫黄用量的提高,混炼胶硫化历程中的平坦期较长,但t90趋于明显降低,静态硫化胶溶出物含量及力学性能均呈下降趋势;当硫黄用量为0.5份时,静态硫化胶及BR/EVA TPV表现出良好的综合性能。显微镜照片表明,BR硫化胶的粒状物平均尺寸为5～10μm左右,较均匀地分散在EVA树脂基体中;FE-SEM的测试表明,TPV的断面平滑,TPV具有良好的形变回复性。     

有机粘土/丁基橡胶和有机粘土/氯化丁基橡胶纳米复合材料的结构与性能

通过熔体插层法制备了有机粘土/丁基橡胶纳米复合材料(IIRCNs)和有机粘土/氯化丁基橡胶纳米复合材料(CIIRCNs),考察了有机粘土用量对纳米复合材料硫化特性、物理性能和气体阻隔性能的影响。结果表明:随着有机粘土用量的增大,IIRCNs和CIIRCNs的t90不断延长,硫化速率降低;拉伸强度和撕裂强度先增大后减小,有机粘土用量为10份时达到最大值;由于加入有机粘土,IIRCNs和CIIRCNs的气体阻隔性能变好,且后者更优。X射线衍射和扫描电子显微镜分析表明,有机粘土用量为10份时,其均匀分散于橡胶基体中,形成了插层型结构。     

二氧化锰结构对液体聚硫橡胶硫化特性及性能的影响研究

针对可控合成的一系列不同结构的二氧化锰进行了表征,并以液体聚硫橡胶为基体,研究了不同结构和性能的二氧化锰对聚硫密封剂硫化特性、力学性能以及耐介质性能的影响。研究结果表明:不同结构二氧化锰硫化液体聚硫橡胶的速率有明显差异,由高到低为:针状花瓣状层状球状;具有同种结构的二氧化锰样品,其粒径越小,硫化效率越高,且硫化后的聚硫密封剂力学性能越好。最后对不同结构二氧化锰硫化的液体聚硫橡胶的耐热和耐介质性能进行了表征,其中针状二氧化锰硫化的聚硫橡胶具有较优的综合性能。     

Preparation and properties of nanocomposites based on different polarities of nitrile–butadiene rubber with clay

Nanocomposites were prepared with different grades of nitrile–butadiene rubber (NBR) [with nitrile (CN) contents of 26, 35, and 42%] with organoclay (OC) by a melt‐compounding process. The rubber/clay nanocomposites were examined by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). An increase in the polarity of NBR affected the XRD results significantly. The dispersion level of the nanofiller in the nanocomposites was determined by a function of the polarity of the rubber, the structure of the clay, and their mutual interaction. The intercalated structure and unintercalated structure coexisted in the lower polar of NBR. In addition, a relatively uniformly dispersed state corresponded to a more intercalated structure, which existed in the higher polar of NBR matrix. Furthermore, high‐pressure vulcanization changed the extent of intercalation. The mechanical properties and gas barrier properties were studied for all of the compositions. As a result, an improvement in the mechanical properties was observed along with the higher polarity of NBR. This improvement was attributed to a strong interaction of hydrogen bonding between the CN of NBR and the OH of the clay. Changes in the gas barrier properties, together with changes in the polarity of the rubbers, were explained with the help of the XRD and TEM results. The higher the CN content of the rubber was, the more easily the OC approached to the nanoscale, and the higher the gas barrier properties were. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Impact of curing temperature on microstructures and properties of isobutylene–isoprene rubber/clay nanocomposites

In this work, the influence of curing temperature on microstructures of isobutylene–isoprene rubber/clay nanocomposites (IIRCNs) prepared by melt compounding was characterized using wide‐angle X‐ray diffraction and TEM. The gas barrier and tensile properties of IIRCN cured under different temperature were examined. The results reveal that high pressure, curing reactions, and reactions of amine intercalants with curing agents together play important roles on determining the final microstructures of cured IIRCNs. Changing curing temperature would dramatically alter intercalated structure, dispersion homogeneity, filler–rubber interaction strength, and crosslinking density of obtained IIRCN, resulting in great difference in final properties. Finally, some suggestions for the preparation of successful RCNs were proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Fabrication of regenerated cellulose nanoparticles/waterborne polyurethane nanocomposites

Regenerated cellulose nanoparticles (RCNs) are ideal materials for new biomass polymer composites industries. RCNs and composites of RCNs and water‐borne polyurethane (RCN/WPU) were prepared using a facile and environmentally friendly approach without the use of any harmful chemicals. The morphological, thermal, and mechanical properties of the RCN/WPU nanocomposite were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), rheometer, wide‐angle X‐ray diffraction, and enzymatic hydrolysis. RCNs exhibited low crystallinity upon regeneration with an NaOH‐based aqueous solution, and were identified by SEM and TEM to consist of the more thermodynamically stable cellulose form. TGA showed that the thermal stability of RCN/WPU nanocomposites was increased by the addition of RCNs. Finally, enzymatic hydrolysis using cellulase indicated that the biodegradability of RCN/WPU nanocomposites was also improved. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46633.     

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     

辐射预硫化炭黑/白炭黑天然橡胶胶料性能对比研究

对炭黑和白炭黑分别填充的天然橡胶(NR)胶料进行电子辐射预硫化,研究辐射预硫化对胶料的结合胶含量、门尼粘度和硫化特性及硫化胶的物理性能和动态性能的影响。结果表明,辐射预硫化能提高胶料的结合胶含量、门尼粘度和硫化速度,对两种硫化胶的应力应变、生热和磨耗等性能产生不同的影响,并能显著抑制填料在橡胶基体内网络结构的形成,降低胶料的滞后损失。     

Preparation and characterization of poly(styrene‐co‐butadiene) and polybutadiene rubber/clay nanocomposites

Poly(styrene‐co‐butadiene) rubber (SBR) and polybutadiene rubber (BR)/clay nanocomposites have been prepared. The effects of the incorporation of inorganically and organically modified clays on the vulcanization reactions of SBR and BR were analysed by rheometry and differential scanning calorimetry. A reduction in scorch time (t_s1) and optimum time (t₉₅) was observed for both the rubbers when organoclay was added and this was attributed to the amine groups of the organic modifier. However, t_s1 and t₉₅ were further increased as the clay content was increased. A reduction in torque value was obtained for the organoclay nanocomposites, indicating a lower number of crosslinks formed. The organoclays favoured the vulcanization process although the vulcanizing effect was reduced with increasing clay content. The tensile strength and elongation of SBR were improved significantly with organoclay. The improvement of the tensile properties of BR with organoclay was less noticeable than inorganic‐modified clay. Nevertheless, these mechanical properties were enhanced with addition of clay. The mechanical properties of the nanocomposites were dependent on filler size and dispersion, and also compatibility between fillers and the rubber matrix. Copyright © 2004 Society of Chemical Industry     

Gas transport through nano and micro composites of natural rubber (NR) and their blends with carboxylated styrene butadiene rubber (XSBR) latex membranes

The gas permeability coefficient of nano and micro composites of natural rubber, carboxylated styrene butadiene rubber and 70:30 natural rubber/carboxylated styrene butadiene rubber blend membranes has been investigated with special reference to type of filler, gases, filler loading and pressure. The layered silicates such as sodium bentonite and sodium fluorohectorite were the nanofillers used and the conventional micro fillers were clay and silica. Latex nanocomposites were characterized by X-ray diffraction technique. The dispersion of layered silicates in the polymer matrix was analysed using transmission electron microscopy. The fluorohectorite silicate showed excellent dispersion in natural rubber matrix. The effect of free volume on the gas barrier properties was investigated by positron annihilation lifetime spectroscopy. It was observed that due to the platelet like morphology and high aspect ratio of layered silicates, the gas barrier properties of nano filled latex membranes were very high. The crosslink density values and extent of reinforcement were estimated in order to correlate with the gas barrier properties. The oxygen/nitrogen selectivity of these membranes were investigated. The diffusion of gas molecules through the polymer was determined by time-lag method and diffusion selectivity of the membranes was computed.     

助交联剂在氢化丁腈橡胶中的应用研究

研究了添加不同用量的助交联剂齐聚酯和三甲基丙烯酸三羟甲基丙烷酯(TMPTMA)氢化丁腈橡胶的硫化特性、力学性能,并对比了两种助交联剂对氢化丁腈橡胶的硫化特性、力学性能、老化性能、高温拉伸性能、耐磨性能和加工性能的影响。结果表明：随着齐聚酯和TMPTMA含量的增加,橡胶的扭矩增大,硫化时间缩短;拉伸强度基本不变,硬度、100%定伸应力、撕裂强度逐渐提高,拉断伸长率、回弹性减小。与添加齐聚酯的橡胶相比,添加TMPTMA橡胶的扭矩较大,硫化时间较短;对比添加齐聚酯和TMPTMA的橡胶,它们的力学性能、老化性能、高温拉伸性能和耐磨性能都非常接近,可见它们在硫化过程中的作用原理相似。由橡胶加工分析仪可知,添加TMPTMA橡胶的储能模量较小,损耗因子较大。     

丙烯酸酯类助交联剂在硅橡胶中的应用

研究了丙烯酸酯类助交联剂对硅橡胶硫化性能、力学性能、粘弹性能的影响。结果表明,助交联剂显著降低了硅橡胶的硫化时间、撕裂强度,明显提高了硫化胶的硬度、拉伸永久变形、模量和损耗因子,使硅橡胶在宽温域内的阻尼性能、模量稳定性得到极大的改善,为准恒模量阻尼硅橡胶的研究提供了新的方向。