Effect of filler geometry on the diffusion and transport behavior of aromatic solvents and commercial oil through nitrile rubber nanocomposites

The diffusion and transport behavior of nitrile rubber nanocomposites was studied with respect to different types of filler and also different types of solvents. The nitrile rubber nanocomposites showed considerable variations in the molecular transport owing to the tortuosity of path, decreased segmental mobility, and difference in particle geometry. As the matrix under consideration is polar, the behavior of the filled systems in aniline was also studied with a view to understand the polar–polar interaction between the filled matrix and the solvent. The oil repellency as a result of filler addition in the matrix was investigated by studying oil uptake of the nanocomposites. In all these investigations, it has been observed that the filler geometry played an important role in controlling the molecular transport through the polymer matrix. The layered silicate‐filled system showed better solvent resistance and hence minimum solvent uptake in polar and nonpolar solvents and better oil repellency followed by titanium dioxide and calcium phosphate filled systems. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

HNBR补强填充体系的研究

研究了白炭黑及改性酚醛树脂（SP6701）对氢化丁腈橡胶（HNBR）补强效果的影响。结果表明,在N550用量不变的情况下,白炭黑的加入能显著提高HNBR硫化胶的定伸应力和硬度,改善HNBR的耐热空气老化性能;加入SP6701后,胶料的拉伸强度逐渐降低,拉断伸长率先降低后升高,硬度和定伸应力则显著增大,混炼胶的Payne效应则是随着SP6701含量的增加而增强。综合而言,SP6701能够明显提高硫化胶的硬度和定伸应力,但对于其它性能的影响很微弱,甚至会产生相反的影响。     

累托石/丁腈橡胶纳米复合材料的结构与性能

用乳液共混共凝法制备了累托石／丁腈橡胶(NBR)复合材料,分别进行了透射电镜分析和X射线衍射分析,研究了其力学性能和气体阻隔性能。结果表明,累托石以厚度为10．00nm左右的晶束均匀分散于NBR中;累托石／NBR复合材料属于隔离型纳米复合材料;与传统的炭黑／NBR复合材料和白炭黑／NBR复合材料相比,累托石／NBR纳米复合材料具有高的邵尔A型硬度和300％定伸应力．尤其是其气体阻隔性能得到了显著提高。     

白炭黑-硅烷填充剂体系的化学性质及其对橡胶的补强性能

目前,降低燃油消耗,提高轿车轮胎的行驶性能及湿路面抓着力是个热门话题。文中详细论述了硅烷偶联剂TESPT及TESPD和沉淀法白炭黑-硅烷填料体系在SSBR／BR（70／30）胶料中的使用,白炭黑．硅烷-橡胶结合的化学反应机理以及对橡胶补强性能的提高。     

Effect of different nanoparticles on thermal,mechanical and dynamic mechanical properties of hydrogenated nitrile butadiene rubber nanocomposites

Organically modified and unmodified montmorillonite clays (Cloisite NA, Cloisite 30B and Cloisite 15A), sepiolite (Pangel B20) and nanosilica (Aerosil 300) were incorporated into hydrogenated nitrile rubber (HNBR) matrix by solution process in order to study the effect of these nanofillers on thermal, mechanical and dynamic mechanical properties of HNBR. It was found that on addition of only 4 phr of nanofiller to neat HNBR, the temperature at which maximum degradation took place (T_max) increased by 4 to 16°C, while the modulus at 100% elongation and the tensile strength were enhanced by almost 40–60% and 100–300% respectively, depending upon nature of the nanofiller. It was further observed that T_max was the highest in the case of nanosilica‐based nanocomposite with 4 phr of filler loading. The increment of storage modulus was highest for sepiolite‐HNBR and Cloisite 30B‐HNBR nanocomposites at 25°C, while the modulus at 100% elongation was found maximum for sepiolite‐HNBR nanocomposite at the same loading. A similar trend was observed in the case of another grade of HNBR having similar ACN content, but different diene level. The results were explained by x‐ray diffraction, transmission electron microscopy, and atomic force microscopy studies. The above results were further explained with the help of thermodynamics. Effect of different filler loadings (2, 4, 6, 8, and 16 phr) on the properties of HNBR nanocomposites was further investigated. Both thermal as well as mechanical properties were found to be highest at 8 phr of filler loading. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Reinforcement effect of nanocellulose on thermal stability of nitrile butadiene rubber (NBR) composites

Poor physical and chemical attraction between nitrile butadiene rubber (NBR) matrix and filler resulted in low thermal properties. Therefore, nanocrystalline cellulose (NCC) as a reinforcement agent was used to increase the heat resistance and thermal stability of NBR composites. The addition of 2 phr NCC increased thermal stability and activation energy of NBR up to 75%. Meanwhile, the storage modulus of composites increased by 12 GPa at the similar loading of NCC. Good interfacial bonds of electrostatic interactions, formation of hydrogen bonds, crystallinity and nanosized of NCC are the main factors contribute to the final properties of NBR/NCC composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46594.     

离子液体改性炭黑增强丁腈橡胶的研究

先采用离子液体（1-丁基-3-甲基咪唑六氟磷酸盐BMIM.PF6,IL）处理炭黑,而后进行微波处理得到改性炭黑（m-CB）,将m-CB用于增强丁腈橡胶（NBR）。研究了m-CB的结构、混炼胶的硫化特性和补强效果。结果表明,IL可吸附到炭黑表面,而且部分IL强烈吸附于炭黑表面,微波处理之后,IL会发生部分分解;m-CB使混炼胶的硫化延迟;NBR/m-CB硫化胶的断裂伸长率、拉伸和撕裂强度相对于未改性炭黑均有较大提高,而模量和硬度略有下降。通过对硫化胶的交联密度、动态力学分析（DMA）、形态学等研究,探讨了改性炭黑补强橡胶机理。     

Characterization of polypropylene/polystyrene boehmite alumina nanocomposites: Impact of filler surface modification on the mechanical,thermal, and rheological properties

The influences of surface treatment and the concentration of boehmite alumina (BA) particles on polypropylene and polystyrene (PS) (80/20) blends produced via melt compounding were examined. The results show that p‐toluene sulfonic acid‐treated BA particles yielded the highest stiffness improvement (27.5%), followed by untreated particles (25.7%), and dodecylbenzene sulfonic acid‐treated BA particles (8.5%). Transmission electron microscopy revealed that p‐toluene sulfonic acid‐treated BA particle agglomerates were dispersed in the PS phase, whereas untreated particles formed agglomerations at the interfaces. Dodecylbenzene sulfonic acid‐treated particles were poorly dispersed in both matrices. Differential scanning calorimetry showed that both untreated and p‐toluene sulfonic acid‐treated BA particles acted as nucleating agents in the blend because of the shifting of crystallization peaks to higher temperatures by 12 and 8 °C, respectively. A significant increase in decomposition temperatures occurred upon 7 wt % loading of all types of BA particles into the blend. Heat deflection temperature measurements showed that all types of BA particles improved the thermal properties of the blend. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46376.     

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%。     

Preparation and mechanical properties of nitrile butadiene rubber/silicate nanocomposites

Elastomer nanocomposites consisting of nitrile butadiene rubber (NBR) latex and layered silicates are prepared by a modified latex shear blending process aided with ball milling. The mode of dispersion of layered silicates in NBR is partially exfoliated and intercalated when the concentration of layered silicates is below 7.5 wt%, as evidenced by transmission electron microscopy and X-ray diffraction results. The tensile and tear mechanical properties are much higher than that of neat NBR. Specifically, the tensile and tear mechanical properties of the NBR/layered silicates increase by 200 and 60%, respectively. The decomposition temperature of the nanocomposites increases slightly.     

Influence of molecular parameters on thermal,mechanical, and dynamic mechanical properties of hydrogenated nitrile rubber and its nanocomposites

The present work derives a relationship between structure and properties of hydrogenated nitrile rubber (HNBR) in the presence as well as absence of nanofillers. Four different grades of HNBR were selected to examine the influence of polarity, unsaturation, and molecular weight on thermal, mechanical, and dynamic mechanical properties of the elastomers and particularly their nanocomposites. An increase in thermal stability, tensile strength, modulus at 100% elongation as well as storage modulus of the unfilled rubber was observed with increase in polarity (acrylonitrile content). Different nanofillers, such as montmorillonite, sepiolite, and nanosilica were used to improve the above properties of the unfilled rubber. Interestingly, a reverse trend of thermal properties was observed for the nanocomposites with acrylonitrile variation, although mechanical and dynamic mechanical properties exhibited similar trend to those of the unfilled rubber. These properties, however, gradually deteriorated as the level of unsaturation on the polymer backbone was increased. On addition of the nanofillers, it was found that the improvement in thermal and mechanical properties was higher for the elastomer having 5.5% diene content. The results were explained by X‐ray Diffraction, Atomic Force Microscopy, Energy Dispersive X‐ray mapping, and swelling studies. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

淀粉对蒙脱土/丁腈橡胶纳米复合材料结构和性能的影响

采用蒙脱土水悬浮液/橡胶乳液共混-共凝复合技术制备蒙脱土/丁腈橡胶纳米复合材料时,在蒙脱土水悬浮液和丁腈胶乳的混合体系中加入淀粉,考察了淀粉用量对蒙脱土/丁腈橡胶纳米复合材料结构和性能的影响。结果表明,淀粉的加入有利于蒙脱土片层形成剥离型结构。当蒙脱土用量为5份、淀粉用量为10份时,蒙脱土几乎呈完全剥离状态;随着淀粉用量的增加,该复合材料的邵尔A硬度、100%定伸应力、拉伸强度、扯断伸长率和撕裂强度均有所提高。     

Effect of silica filler on aluminum-aluminum bonding by a self-vulcanizable blend based on chlorobutyl rubber and carboxylated nitrile rubber

Silica filler improves the aluminum-aluminum bonding by a self-vulcanizable rubber blend based on chlorobutyl rubber and carboxylated nitrile rubber. The joint peel strength depends on the filler loading, the state of cure, the molding temperature, and the adhesive film thickness. The higher peel strength in the filled adhesive system is due to filler reinforcement resulting in tear path deviation and the formation of Si—O—Al linkage at the aluminum-adhesive interface. Maximum peel strength was obtained at 10 phr filler loading, when the molding temperature was 180°C and the molding pressure was 0.35 MPa.     

Morphology and rheological properties of nanocomposites based on nitrile rubber and organophilic layered silicates

Organo‐montmorillonite/nitrile rubber (NBR) nanocomposites were prepared by a melt intercalation process. The characteristics of NBR nanocomposites were determined by an oscillating disk rheometer and transmission electron microscopy. The cure characteristics were investigated according to the change in clay content and clay types. This study confirmed that organo‐montmorillonite/NBR nanocomposites have various cure characteristics, namely minimum torque, maximum torque, scorch time and curing time, according to the change in clay content and clay types. In particular, as the chain length of the modifier used for the treatment of Na⁺‐MMT following vulcanization increases, scorch time and optimum curing time are reduced. This is because, as the chain length of the modifier increases, organo‐MMT is distributed more equally during the formation of the nanocomposites. As swelling increases, the chain length of the clay modifier expands and then constitutes a better barrier. Copyright © 2003 Society of Chemical Industry     

填料-橡胶的化学和物理作用及其对补强的影响

研究了炭黑N330和白炭黑与NR／BR的相互作用及其对补强的影响。炭黑N330与NR/BR相互作用的化学交联密度占40％，对拉伸强度的贡献率为82．8％；白炭黑/偶联剂KH—846与NR/BR相互作用的化学交联密度占66．7％，对拉伸强度的贡献率为80．7％；炭黑／白炭黑/偶联剂KH-846与NR/BR相互作用的化学交联密度约占70％，对拉伸强度的贡献率约占94％。3种补强体系对拉伸强度的贡献都是化学作用占优势，贡献率超过80％。     

Viscoelasticity and thermal stability of poly(arylene ether nitrile) nanocomposites with various functionalized carbon nanotubes

Poly(arylene ether nitrile) (PEN) nanocomposites containing various functionalized multi‐walled carbon nanotubes (MWCNTs) were prepared through a solution‐casting method. The as‐prepared PEN nanocomposites were investigated using parallel‐plate rheometry and thermogravimetric analysis, aimed at examining the effect of surface functionalization on the dispersion of MWCNTs from the viscoelastic and thermal properties. The linear viscoelasticy results indicated that 4‐aminophenoxyphthalonitrile‐grafted MWCNTs presented better dispersion in the PEN matrix than purified and carboxylic MWCNTs because the corresponding composite showed the lowest rheological percolation threshold, which was further confirmed from scanning electron microscopy, dissolution experiments and solution rheological experiments. The thermogravimetric analysis results revealed that the presence of 4‐aminophenoxyphthalonitrile‐grafted and carboxylic MWCNTs retarded the depolymerization compared with purified MWCNTs, showing a marked increase in the temperature corresponding to a loss of 5 wt% (increased by 14–22 °C) and maximum rate of decomposition (increased by 4–8 °C). Both the state of dispersion and the surface functionalization of MWCNTs are very important to the thermal stability of the PEN matrix. Copyright © 2011 Society of Chemical Industry     

丁腈橡胶/聚氯乙烯/有机蒙脱土纳米复合材料的结构与性能

采用胶乳共沉法和直接共混法制备了丁腈橡胶／聚氯乙稀／有机蒙脱土（NBR／PVC／OMMT）纳米复合材料。通过X射线衍射（XRD）法和透射电子显微镜（TEM）法对NBR／PVC／OMMT纳米复合材料的结构进行了袁征,并研究了复合材料的力学性能、耐油性能和耐老化性能。结果表明,2种方法所获得的复合材料是插层型纳米复合材料;胶乳共沉法制备的纳米复合材料中OMMT的分散更为均匀,其力学性能、耐油性能和耐老化性能优于直接共混法制备的复合材料。     

乳液法天然橡胶/丁腈橡胶/蒙脱土纳米复合材料的结构与性能

采用乳液法制备了天然橡胶/丁腈橡胶/蒙脱土纳米复合材料,考察了其微观形态,探讨了复合材料的硫化特性及静态和动态力学性能.结果表明,蒙脱土以纳米尺寸均匀分布于丁腈橡胶基质中,橡胶分子链并未插层进入蒙脱土片层;蒙脱土使复合材料的焦烧时间和正硫化时间增加,可明显提高复合材料的静态力学性能;复合材料具有与天然橡胶/丁腈橡胶共混...     

Dynamics near the filler surface in natural rubber-silica nanocomposites

We study the effect of in situ synthesized 10 nm silica nanoparticles on the glass transition and dynamics of natural rubber networks using differential scanning calorimetry, broadband dielectric relaxation spectroscopy and thermally stimulated depolarization currents. Even in the absence of specific polymer-filler interactions, polymer segments within a few nanometers of the filler particles exhibit relaxation times up to 2-3 orders of magnitude slower and reduced heat capacity increment at the glass transition compared to bulk natural rubber. These effects are only observed when the nanoparticles are uniformly distributed in the polymer matrix.     

Effect of silica filler on dynamic mechanical properties of lonic elastomer based on carboxylated nitrile rubber

Variation of dynamic mechanical propeties like storage modulus (E′) and loss tangent (tan δ) with temperature show the presence of two transitions in the carboxylated nitrile rubber (XNBR) molded in the presence of zinc oxide (ZnO). The low-temperature transition is due to the glass–rubber transition (T_g) of XNBR, and the high-temperature transition is due to formation of ionic clusters. Incorporation of reinforcing silica filler makes the high temperature transition more prominent and high filler loading casues a shift of the transition temperature to the higer side. It is believed that the rubber–filler interaction in the cluster region causes striking changes in the variation of E′ and tan δ with a double-strain amplitude (DSA). © 1995 John Wiley & Sons, Inc.