偶联剂改性对磁敏NR/SBR并用胶性能的影响

将NR和SBR与改性羰基铁粉机械共混制备磁敏NR/SBR并用胶,研究偶联剂KH-550,KH-560,KH-570和NDZ-401改性羰基铁粉对磁敏NR/SBR并用胶的物理性能和磁流变效应的影响。结果表明:不同偶联剂改性的羰基铁粉对NR/SBR并用胶性能有一定的影响;采用偶联剂KH-570改性的羰基铁粉填充的NR/SBR并用胶表现出较好的物理性能和磁流变效应。     

热重分析法测定橡胶并用比

研究热重（TG）分析法测定橡胶并用比。通过对天然橡胶（NR）、顺丁橡胶（BR）和不同种类丁苯橡胶（SBR）进行TG分析,得到不同样品用量NR、不同种类SBR以及BR和SBR与NR不同并用比并用胶的TG分析曲线,提出面积法计算NR/SBR和NR/BR并用胶并用比的方法。结果表明该方法得到的并用胶并用比在两种橡胶用量接近时具有很高的准确性,随着两种橡胶用量差的增大准确性有所下降。     

天然橡胶/丁苯橡胶/反式丁戊橡胶并用胶的性能研究

研究反式丁戊橡胶（TBIR）对天然橡胶（NR）/丁苯橡胶（SBR）并用胶性能的影响。结果表明：用15份TBIR替代NR,NR/SBR/TBIR并用胶的NR与SBR相容性改善,拉伸强度和定伸应力略有降低,耐磨性能、耐压缩疲劳性能和耐屈挠疲劳性能提高;用15份TBIR替代SBR,NR/SBR/TBIR并用胶的NR与SBR相容性明显改善,拉伸性能变化不大,耐磨性能、耐压缩疲劳性能和耐屈挠疲劳性能提高;用15份TBIR替代NR/SBR并用胶,NR/SBR/TBIR并用胶的大部分性能介于TBIR单独替代NR与SBR并用胶的性能之间,抗湿滑性能提高,滚动阻力降低;在NR/SBR并用胶中直接加入6份TBIR,NR/SBR/TBIR并用胶的NR与SBR相容性改善,耐磨性能、耐压缩疲劳性能和耐屈挠疲劳性能提高,抗湿滑性能和滚动阻力降低。     

磁性橡胶的制备与性能研究

以聚乙二醇(PEG)6000表面改性的四氧化三铁为磁性填料制备改性四氧化三铁/NR/EPDM磁性橡胶,并对其微观结构、耐老化性能、耐酸碱性能、耐油性能和低温脆性进行研究.结果表明:以NR/EPDM并用胶为基体制备的磁性橡胶耐热老化性能、耐臭氧老化性能、耐酸碱性能和耐油性能均高于以NR为基体的磁性橡胶;基体橡胶种类对磁性橡胶的低温脆性影响不大.     

改性三氧化二钇补强橡胶的研究

采用偶联剂Si69对三氧化二钇进行表面改性,研究改性三氧化二钇对NR/BR并用胶的补强效果.红外光谱和热重分析表明,在改性三氧化二钇的表面键合了偶联剂Si69;改性三氧化二钇/NR/BR复合材料的拉伸强度和拉断伸长率比未改性三氧化二钇/NR/BR复合材料明显提高;扫描电子显微镜观察发现,改性三氧化二钇在橡胶基体中分布均匀,与橡胶的相容性很好。     

新型白炭黑改性橡胶研究

采用2种新型白炭黑替代常用白炭黑来改性天然橡胶（NR）、顺丁橡胶（BR）、丁笨橡胶（SBR）、三元乙丙橡胶（EPDM）、丙烯酸酯橡胶（ACM）和硅橡胶。研究不同用量和不同种类的白炭黑对上述几种橡胶进行改性,通过对硬度、扯断伸长率、拉伸强度、磨耗和耐老化性能的测试,确定白炭黑的最佳用量和最适宜的种类。结果表明：白炭黑填料用量为80份时效果最好,普通白炭黑适合做EPDM的补强剂,碱法白炭黑对NR、SBR和ACM的改性效果更好,而酸法白炭黑改性的橡胶拉伸强度和硬度很小,不适于补强;白炭黑对硅橡胶的改性效果不好,得到的产品硬度很小,无法进行力学性能测试。     

改性羰基铁粉对天然橡胶基磁流变弹性体性能的影响

选取离子液体1-烯丙基-3甲基咪唑氯(AMI)、硅烷偶联剂γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH570)、油酸(OA)和硬脂酸(SA)改性羰基铁粉(CIP)粒子,研究了改性羰基铁粉对天然橡胶(NR)基磁流变弹性体(MRE)力学性能、微观结构、磁流变性能和热稳定性的影响。结果表明:加入改性剂后,磁性颗粒在橡胶基体中排列更加规整,团聚减少,MRE相对磁流变效应均有上升,并且OA的改性效果最好;改性羰基铁粉填充NR基MRE的的热稳定性降低。     

硫化胶中橡胶种类的定性和定量分析

采用裂解-气相色谱/质谱（Py-GC/MS）法研究子午线轮胎常用的4种橡胶天然橡胶（NR）、丁苯橡胶（SBR）、顺丁橡胶（BR）和溴化丁基橡胶（BIIR）及其并用胶NR/SBR,SBR/BR,NR/BR和NR/BIIR,确定4种橡胶的特征裂解产物,建立Py-GC/MS法定性定量分析未知硫化胶中并用橡胶的方法。结果表明,本方法在未知硫化胶分析时定性分析非常准确,可做半定量分析,重复性良好,相对标准偏差为0.01%。     

橡胶补强剂HDP在内胎配方中的应用

HDP橡胶补强剂主要成分是特种矿藏、偶联剂、碳酸酯增粘剂等多种原材料,经过烘干粉碎分解活化而成,其补强作用主要在于它的微细粒子填充到硫化橡胶的主体网状结构之间。内胎配方采用NR/SBR并用,在使用HDP橡胶补强剂同时降低NR使用量,可达到在降低生产成本的同时保证内胎成品的使用要求。     

碳酸钙晶须增强炭黑NRNBR橡胶复合材料的研究

天然橡胶（NR）与丁腈橡胶（NBR）共混,共混胶兼并NR物理机械性能及NBR耐油性能,但炭黑补强/NR/NBR橡胶复合材料物理机械性能相比炭黑补强NR橡胶复合材料差。在炭黑补强/NR/NBR橡胶复合材料中,加入碳酸钙晶须旨在增强复合材料物理机械性能,提高其使用范围。本文采用钛酸酯偶联剂对碳酸钙晶须进行改性,研究改性后碳酸钙晶须对炭黑/ NR/ NBR橡胶复合材料性能的影响。结果表明：钛酸酯偶联剂改性后的碳酸钙晶须,表面性能改变,有效提高了碳酸钙晶须与炭黑/NR/NBR橡胶复合材料的相容性。当碳酸钙晶须用量为4份时,复合材料的综合性能最佳,有效改善复合材料Payne效应。     

Enhancement of the rheological properties of magnetorheological elastomer via polystyrene-grafted carbonyl iron particles

In this work, carbonyl iron particles (CIP) was grafted with polystyrene coating on its surface via polymerization method, and the coated-CIPs were then embedded into a silicone rubber with the ratio of 70:30 of CIP to silicone rubber in order to enhance the rheological properties of magnetorheological elastomer (MRE) in terms of lower initial storage modulus and higher MR effect. By using field emission scanning electron microscopy (FESEM) that is equipped with the energy dispersive X-ray spectroscopy for elemental analysis, it was observed that elements of C, N, O, Si, Fe, Br, Cu, and Sn were detected, confirming that the coating layer has been successfully developed on the CIP. Additionally, the investigation of the rheological characteristics was conducted at 25°C with three different sweep conditions using rheometer MCR 302. Firstly the strain amplitude was swept from 0.001% to 10% strain with 1 Hz frequency. Then, the frequency was varied from 1 Hz to 100 Hz under 0.01% strain at an applied current of 0–5 A. Lastly, the current was swept from 0 to 5 A under 0.01% strain amplitude and 1 Hz excitation frequency. It was discovered that the storage modulus of the polystyrene-coated CIP MRE is lower than that of uncoated-CIP MRE in all three sweep profiles. Advantageously, the magnetorheological (MR) effect of the coated-CIP MRE sample is higher than that of the uncoated-CIP MRE by 28.04%. Moreover, it was found that the coated-CIP MRE exhibited higher damping behavior with more than 0.14 loss factor than 0.12 loss factor of the uncoated sample. The dimensional stability of polystyrene coating on the CIP was an attributing factor to this enhanced damping behavior of the coated-CIP MRE. Thus, it became clear that the polystyrene-coated CIP embedment in MRE is more desirable than that of MRE with uncoated CIP.     

油田用磁流变弹性体室内研究

磁流变弹性体（MRE）是将磁性粒子分散在高聚物基体中,固化后形成的复合材料.相较于磁流变液,具有不易沉降、性能稳定、控制可逆、响应迅速等优点,MRE作为新兴的智能材料,在石油钻采领域有广泛的应用前景.制备了以天然橡胶（NR）为基体,不同磁性粒子含量的各向同性和各向异性MRE,分析了样品的磁流变性能、物理机械性能和耐油性能.结果表明,随着磁性粒子含量的上升,样品的磁流变性能、交联密度、热稳定和耐油性能都明显提升,但力学性能所下降.在500 mT外加磁感应强度下,50％的各向异MRE相对磁流变效应为26.87％,绝对磁流变效应为0.61 MPa.     

Thermal Aging Rheological Behavior of Magnetorheological Elastomers Based on Silicone Rubber

Engineering rubber composites have been widely used as main components in many fields including vehicle engineering and biomedical applications. However, when a rubber composite surface area is exposed to heat or sunlight and over a long-term accelerated exposure and lifecycle of test, the rubber becomes hard, thus influencing the mechanical and rheological behavior of the materials. Therefore, in this study, the deterioration of rheological characteristics particularly the phase shift angle (δ) of silicone rubber (SR) based magnetorheological elastomer (MRE) is investigated under the effect of thermal aging. SR-MRE with 60 wt% of CIPs is fabricated and subjected to a continuous temperature of 100 °C for 72 h. The characterization of SR-MRE before and after thermal aging related to hardness, micrograph, and rheological properties are characterized using low vacuum scanning electron microscopy (LV-SEM) and a rheometer, respectively. The results demonstrated that the morphological analysis has a rough surface and more voids occurred after the thermal aging. The hardness and the weight of the SR-MRE before and after thermal aging were slightly different. Nonetheless, the thermo-rheological results showed that the stress–strain behavior have changed the phase-shift angle (δ) of SR-MRE particularly at a high strain. Moreover, the complex mechanism of SR-MRE before and after thermal aging can be observed through the changes of the ‘in-rubber structure’ under rheological properties. Finally, the relationship between the phase-shift angle (δ) and the in-rubber structure due to thermal aging are discussed thoroughly which led to a better understanding of the thermo-rheological behavior of SR-MRE.     

各向同性与各向异性天然橡胶磁流变弹性体的导热性能及磁流变性能（英文）

采用羰基铁粉粒子填充天然橡胶磁流变弹性体(MRE),研究了各向同性与各向异性MRE的磁流变性能及导热性能。结果表明,各向异性MRE的热扩散系数和导热系数比各向同性MRE分别提高了30. 1%和41. 9%。同时,随着应变的增大,MRE的相对磁流变效应呈下降趋势,而在相同应变下,各向异性MRE的储能模量以及相对磁流变效应均高于各向同性MRE。     

Magnetic (ethylene–octene) elastomer composites obtained by extrusion

Most research on magnetorheological elastomer (MRE) composites is focused on achieving the best magnetic and magnetorheological properties of composites. Less attention is paid to obtain adequate strength properties. The aim of this study was to receive MRE composites with the best mechanical characteristics. Thermoplastic ethylene–octene rubber composites, filled with different magnetoactive particles were reported. The use of extrusion method instead of traditional preparation processes (two‐roll mill, mixer) of composites was also presented. Ferromagnetics: micro‐ and nano‐sized iron oxides, as well as gamma iron oxide and carbonyl iron powder were found to be an active fillers improving both mechanical and magnetic properties of rubber. Application of extrusion process affected mechanical properties of MRE composites and the dispersion of magnetic fillers. Dynamic mechanical analysis (DMA) indicates the presence of strongly developed secondary structure in vulcanizates. Studies investigated by vibration sample magnetometer (VSM) proved that all composites exhibit adequate magnetic properties, predispose them for plenty of applications with the most promising being nowadays tunable vibration absorbers. POLYM. ENG. SCI., 57:520–527, 2017. © 2016 Society of Plastics Engineers     

Improving the magnetorheological properties of polyurethane magnetorheological elastomer through plasticization

The highly filled anisotropic polyurethane (PU) magnetorheological elastomers (MREs) were prepared through an in‐situ one‐step polycondensation process under a magnetic field. The carbonyl iron formed chain‐like structure, which was fixed in the PU matrix. The plasticizer diisooctyl phthalate (DOP) was incorporated into PU to soften the matrix and improve the MR effect. The influence of DOP on the microstructure and properties of PU MREs were investigated. The incorporation of DOP reduced the viscosity of the prepolymer and made the carbonyl iron align more easily in the PU matrix. The aligned chain‐like structure of carbonyl iron in PU greatly enhanced the thermal conductivity and the compressive properties of PU MREs. The incorporation of DOP reduced the modulus of PU MREs and the glass transition temperature of the soft segments of PU. But highly filled carbonyl iron and DOP led to a decrease in the thermal stability to some extent. The MR test showed that DOP plasticization significantly enhanced both absolute and relative MR effect simultaneously. With 70 wt% carbonyl iron and 15 wt% DOP (the weight ratio of Fe: PU: DOP is 70 : 15: 15), the absolute and relative MR effects of anisotropic PU MREs were ～ 1.16 MPa and ～ 386.7%, ～ 3.5 and ～ 58 times of the PU MRE without the plasticizer at the same iron content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

橡胶改性及其对橡胶水泥基质材料性能的影响

本文基于提高橡胶-水泥基质材料的力学性质的目的,对橡胶进行磺化-脲化改性.采用水接触角、红外光谱、粘接强度、抗压抗冲击强度等微观宏观测试技术考查了橡胶改性对橡胶水泥基质材料性能的影响.结果表明:橡胶氧化-脲化改性后,在橡胶表面引入了大量羰基、酰胺基等极性亲水性基团,使橡胶表面的浸润类型由憎水性质变为了亲水性质,大大增加了橡胶与水泥基体的界面相互作用,使橡胶与水泥浆体的粘接强度提高了33.4%.橡胶改性对减缓橡胶水泥基质材料的抗压强度降低有确定的效果,但是这种效果在橡胶水泥混凝土中比在水泥砂浆中更突出.橡胶掺量为细集料的30%或以下时,氧化-脲化改性的橡胶混凝土的抗压强度能够达到30 MPa以上,可以满足中等强度混凝土的要求.     

Effects of magnetic field input cycle and peptizer on the MR effect of magneto‐rheological elastomer based on natural rubber

The magneto‐rheological (MR) effect of magneto‐rheological elastomers (MREs) depends on the degree of orientation of carbonyl iron particles, which are dispersed in the elastomeric matrix. In this study, viscosity and molecular weight of NR matrix decreased with the addition of peptizer, and resulted in an increase of MR effect because of the efficient orientation of carbonyl iron particles. Also, the optimum conditions for applying a magnetic field to orient carbonyl iron particles were defined by the input duration time of the magnetic field, rather than the number of input times. Ideal input duration time to induce the orientation of carbonyl iron particles on the elastomeric matrix was 15 minutes. In this system, the MR effect of MRE decreased significantly above 20,000 cycles of cyclic deformation because of interfacial failure between the carbonyl iron particles and the matrix. It was expected that the dynamic property of MRE would increase if the interfacial interaction between carbonyl iron particles and the matrix improved. POLYM. ENG. SCI., 55:2669–2675, 2015. © 2015 Society of Plastics Engineers     

Influence of magnetic field upon the electric capacity of a flat capacitor having magnetorheological elastomer as a dielectric

The flat capacitor is built of two non-magnetic plates (with dimensions 0.065 m × 0.050 m) between which there is a layer of magnetorheological elastomer (MRE). The thickness of the layer is 0.0015 m ± 10%. MRE is based on silicone rubber and iron particles. The iron particles diameter ranges between 0.12 μm and 0.75 μm. The electric capacity, in absence of the magnetic field, is 377 ± 1 pF. In cross magnetic field with strengths up to 94 kA/m, the flat capacitor's capacity increases by up to 200%. For well chosen values of the intensity of the magnetic field, the capacity of the flat capacitor with MRE changes with time. The experimental results obtained in this manner are discussed.