Detailed Mechanism and Engineering Applicability of Electrolytic Polymerization Aided by a Magnetic Field in Natural Rubber by Mechanical Approach for Sensing (Part 1): The Effect of Experimental Conditions on Electrolytic Polymerization

Ordinary electrolytic polymerization has involved plastic-type polymer solutions. Rubber, especially natural rubber, is one such polymer solution. Rubber has not been focused on until recently due to the fact that electrolytic polymerization has only a very small effect on rubber. However, when we focus on the C=C bonds of natural rubber, the same electrolytic polymerization is applicable to be enlarged on the natural rubber if a magnetic field and a filler are added. With the application of a magnetic field and a magnetic responsive fluid such as magnetic compound fluid (MCF), the effect of electrolytic polymerization on NR-latex such as plastic-type polymer solutions is enhanced, and the thickness of the vulcanized MCF rubber grows in a short time. The present new method of vulcanization of MCF rubber is effective enough that it is widely used in haptic sensors in various engineering applications. In the present report, as mechanical approach for the sensing, by measuring the temperature under electrolytic polymerization, by investigating the electric and dynamic characteristics, and by observing the magnified appearance of the MCF rubber, we clarified the extrinsic effects of many experimental conditions, including magnetic field strength, applied voltage, the electrodes gap, mass concentration, and the ingredients of the MCF. This report is Part 1, to be followed by another sequential report, Part 2, in which other intrinsic effects on the characteristics are dealt with. The experimental conditions used and the results obtained in the present report provide valuable data that will be useful in the making of MCF rubber.

Detailed Mechanism and Engineering Applicability of Electrolytic Polymerization Aided by a Magnetic Field in Natural Rubber by Mechanical Approach for Sensing (Part 2): Other and Intrinsic Effects on MCF Rubber Property

The same ordinary electrolytic polymerization of plastic-type polymer solution is applicable to natural rubber, with its C=C bonds, if a magnetic field and a filler are added. With the application of a magnetic field and the magnetic responsive fluid known as magnetic compound fluid (MCF), we have clarified the enhancement of the electrolytic polymerization of NR-latex and the growth of the thickness of vulcanized MCF rubber that results from the addition of a magnetic field. The present new method of MCF rubber vulcanization is effective for use in haptic sensors, which are used widely in various engineering applications. In the previous report, part 1 of this study, we investigated many experimental conditions under mechanical approach for sensing: magnetic field strength;applied voltage;electrodes gap;mass concentration, and the ingredients of the MCF. In the present sequential report, part 2, we investigate many other effects on electrolytic polymerization by the same mechanical approach for sensing as in part 1: the Mullins effect;the Piezo effect;vibration;kind of electrode;atmospheric gas. In particular, we clarify that the voltage generates spontaneously in the MCF rubber and that the MCF rubber becomes a Piezo element. These effects on the electrolytic polymerization as well as the effects of the experimental conditions will be useful in engineering applications. By taking the above-mentioned parameters and effects into account, MCF rubber that is electrolytically polymerized with the aid of a magnetic field, the use of MCF as a filler, and doping, can be useful in haptic sensor applications. In particular, the effectiveness of the Piezo element can be shown.

Temperature field analysis of two rotating and squeezing steel-rubber rollers

Rubber has strong nonlinear viscoelastic characteristic. Under effect of the periodically changing external force,it will show the phenomenon of lagging deformation and mechanical loss,which means deformation lags behind stress changes and the situation of loss of work is caused by the hysteresis. Loss of work will be transformed into thermal energy and makes the temperature of rubber and the object in contact with it rise,which will thereby affect the dynamic characteristics of the structure. Based on a pair of mutual rotating and squeezing steel-rubber rollers as the research object,the finite element simulation software Ansys is used in this paper to analyze the temperature field of the structure. As a result,temperature distribution characteristics of two directions are obtained. One is squeezing area along the direction of the wall,the other is along the direction of thickness of rubber. Then the influence of the rotating speed and the pressure between two rollers on temperature of rubber is analyzed. The temperature experiment of mutual squeezing contact steelrubber roller is carried out on the experimental platform via using infrared thermal imager and infrared thermometer. The experiment data are in accordance with the simulation results on regulation of temperature distribution as well as high degree of similarity on value,which shows the effectiveness of simulation. Research results are of great significance for temperature characteristic analysis of rubber structure.

<i>γ</i>-Ray Irradiation Effect on MCF Rubber Solar Cells with both Photovoltaics and Sensing Involving Semiconductors Fabricated under Magnetic and Electric Fields

For cases in which a robot with installed solar cells and a sensor operates in a nuclear reactor building or in space for extravehicular activity, we require elastic and extensible solar cells. More than two different types of sensing are also required, minimally with photovoltaics and built-in electricity. Magnetic compound fluid (MCF) rubber solar cells are made of rubber, so they are elastic and extensible as well as sensitive. To achieve flexibility and an effective photovoltaic effect, MCF rubber solar cells must include both soluble and insoluble rubbers, Fe3O4, TiO2, Na2WO4∙2H2O, etc. On the basis of this constitution, we propose a consummate fabrication process for MCF rubber solar cells. The characteristics of these cells result from the semiconductor-like role of the molecules of TiO2, Fe3O4, Ni, Na2WO4∙2H2O, polydimethylsiloxane (PDMS), natural rubber (NR), oleic acid, polyvinyl alcohol (PVA), water and magnetic cluster involved in the MCF rubber. Their tendencies can be deduced by synthesizing knowledge about the enhancement of the reverse-bias saturation current IS and the diode ideality factor N, with conventional knowledge about the semiconductor affected by γ-irradiation and the attenuation of the photon energy of γ-rays.

远场和近场地震下核电隔震结构的摇摆响应分析

为了探究远场和近场地震动作用对核电隔震结构的不同影响,研究了核电隔震结构在远场和近场地震动作用下的摇摆响应和支座状态,主要讨论了地震特性对结构摇摆响应的影响,包括上部结构的摇摆角、隔震支座的拉压应力、隔震支座的剪切变形等.分析发现:上部结构的摇摆角随地震动加速度幅值线性增加,其中近场地震动作用下上部结构的摇摆角明显大于远场地震动作用,且具有更大的离散性;当地震动加速度幅值为1.2 g时,近场地震动作用下上部结构摇摆角均值和标准差可达远场地震动作用下的2.88倍和3.90倍;近场地震动作用下,支座更容易进入非安定变形状态,也更容易出现支座受拉现象.该成果可为核电厂结构的隔震设计提供工程参考价值.

橡胶树白粉病拮抗放线菌的筛选及田间防效评价

为筛选对橡胶树白粉病菌具有拮抗作用的生防放线菌,本研究从云南省主要植胶区橡胶树根际土壤中分离放线菌,以橡胶树主要病害病原菌为靶标菌,采用平板对峙培养法初步筛选出1株抑菌效果良好的放线菌菌株,命名为DL5C,其对橡胶树尖孢炭疽菌Colletotrichum acutatum、胶孢炭疽菌C.gloeosporioides、橡胶树白根病病菌Rigidoporus lignosus、橡胶树褐根病病菌Phellinus noxius的抑菌率分别为58.35%、60.97%、60.03%、74.00%;DL5C菌株发酵滤液对橡胶树白粉病菌Oidium heveae孢子萌发的抑制率达72.40%;田间试验结果表明,处理7 d后,DL5C菌株发酵液对橡胶树白粉病的相对防效为80.93%。通过菌株形态特征、培养特征、生理生化特性以及16S rRNA基因序列分析,放线菌菌株DL5C被鉴定为不吸水链霉菌Streptomyces ahygroscopicus。

运行复合绝缘子伞裙的力学特性及分子动力学模拟研究

为更精细化评估伞裙的微观结构和材料组成等因素对绝缘子宏观性能的影响,本文结合分子动力学模拟方法对不同运行年限的交流复合绝缘子进行力学性能、热失重、傅里叶红外光谱等测试。结果表明:随着运行年限的增加,绝缘子从低压端到高压端的伞裙抗撕裂强度、拉伸强度、断裂伸长率整体呈下降的趋势;伞裙外层有机硅和SiO2的含量大幅下降,可造成宏观力学性能下降;在电-热环境下,伞裙的体积模量、杨氏模量和泊松比随温度的升高整体呈下降的趋势,随电场强度的升高整体呈波动性;绝缘子高压端的电场畸变最严重,力学性能最差。本文建立的复合绝缘子伞裙老化的多尺度模型,可为评估绝缘子老化状态提供参考。

Development of Magnetic Compound Fluid Rubber Sensor for Practical Usage on &gamma;-Irradiation and Energy Harvesting for Broad-Band Electromagnetic Waves

We have performed sequential studies on new types of soft rubber for their application as artificial skin in robots and haptic sensors. Based on a proposed electrolytic polymerization method and novel adhesion technique for rubber and a metal that utilizes a metal complex hydrate, we have developed an MCF rubber sensor. This sensor uses a magnetic compound fluid (MCF), natural rubber (NR-latex) or chloroprene rubber latex (CR-latex), and requires the application of a magnetic field. The potential application of the developed sensor in various engineering scenarios and our daily lives is significant. In this regard, we investigated the effects of &gamma;-irradiation, infrared radiation, microwaves, and a thermal source on the MCF rubber sensor. We established that the MCF rubber is effective enough to be used for power generation of broadband electro-magnetic waves from &gamma;-rays to microwaves, including the range of the solar spectrum, which is the typical characteristic obtained in the present investigation. The remarkable attribute is that the MCF rubber sensor dose is not degraded by &gamma;-irradiation. We also demonstrated the effectiveness of the MCF rubber sensor in energy harvesting.

胶管硫化-传热耦合模拟

将导热微分方程热源项与橡胶热物性参数视为硫化度与温度的相关函数,建立传热与硫化的耦合计算方程,并基于C语言编写UDF子程序,对FLUENT软件进行二次开发,实现了传热与硫化的耦合计算。模拟结果表明,靠近管壁的外层胶很快到达硫化温度,而靠近管芯的内层胶到达硫化温度需要较长时间,存在明显的温度梯度。当硫化进行到一定时间后,胶管截面各部位温度差异逐渐减小,各部位温度几乎相同,此时胶管各层的传热达到平衡状态。

多极磁性橡胶编码器的空间磁场分布仿真分析

基于空间磁场理论对多极磁性橡胶编码器的空间磁场分布开展仿真分析与试验研究,获取磁感应强度在气隙高度方向和径向方向的变化规律,证明了仿真分析的准确性。对磁极对数、磁性橡胶层厚度和宽度对多极磁性橡胶编码器的磁感应强度影响规律的仿真结果可为多极磁性橡胶编码器的设计提供指导。

天然橡胶在减震降噪领域的研究进展

本文主要介绍了天然橡胶的研究进展以及其在减振降噪领域的应用;提出了天然橡胶在减振降噪领域面临的主要问题以及未来发展趋势和面临的挑战,为天然橡胶的广泛应用提供参考。

硅橡胶绝缘材料温度及场强依赖特性对XLPE绝缘直流电缆预制接头内电场分布的影响

为选择合适的电缆接头绝缘材料,以改善电缆接头内的电场分布,探究了接头绝缘常用材料硅橡胶的电导温度及场强依赖特性对XLPE直流电缆预制接头中电场分布的影响。首先,针对10 kV电压等级XLPE绝缘直流电缆预制接头结构建立相应的仿真模型。然后,改变硅橡胶材料的电导非线性特征参数,得到对应接头在满载运行状态下的绝缘内电场分布。结果表明:随着硅橡胶材料电导活化能的增大或电导场强依赖系数的减小,接头绝缘交界面处的场强增大,且应力锥根部场强增幅明显;从经济性角度考虑给出硅橡胶与XLPE绝缘材料的电导活化能之比和电导场强依赖系数之比推荐值分别为不高于0.95和不低于0.50,可作为工程上选择确定合适接头绝缘材料的参考。

预制橡胶弹簧浮置板道床动力学仿真及现场测试研究

预制橡胶弹簧浮置板道床多由工厂化生产,再运输至现场进行装配,具有质量可靠、可换性好等优势。为完善预制橡胶弹簧浮置板道床理论分析及测试研究工作,基于深圳地铁6号线支线工程,建立车辆-钢轨-浮置板刚柔耦合模型,开展列车运行的安全平稳性、刚度过渡平顺性及减振效果分析,并进行现场测试研究。结果表明,经动力学仿真,列车在设计最高运行速度120 km/h工况下安全性指标及平稳性指标均满足规范要求;正常刚度段的钢轨最大位移为3.4 mm,前后刚度过渡段的钢轨位移变化率分别为0.09 mm/m和0.11 mm/m,满足限值要求;经现场测试,本工程所采用预制橡胶弹簧浮置板道床的实际减振效果为17.2 dB,满足特殊减振需求。

大扭矩螺杆钻具定子用橡胶材料的研究

从生胶、硫化体系、补强体系和特种功能助剂等着手,通过拉伸性能表征和耐磨性能、弹性模量及门尼粘度等实验比对,制备了大扭矩螺杆钻具用橡胶材料。结果表明,所获橡胶材料Shore A硬度为88,弹性模量在19 MPa以上,比常规产品提高1倍,而且加工性能优良,综合性能佳;通过对成品样机进行台架试验,表明采用该橡胶的螺杆钻具整机效率可提高20%,满足大扭矩螺杆钻具目标要求。

Development of Novel Magnetic Responsive Intelligent Fluid, Hybrid Fluid (HF), for Production of Soft and Tactile Rubber

For the purpose of the replacement of Magnetic Fluid (MF) which is effective in the production of an artificial soft and tactile skin for the robot, etc. by utilizing a rubber solidification method with electrolytic polymerization, we proposed a novel magnetic responsive intelligent fluid, Hybrid Fluid (HF). HF is structured with water, kerosene, silicon oil having Polydimethylsiloxane (PDMS) and Polyvinyl Alcohol (PVA) as well as magnetic particles and surfactant. The state of HF changes as jelly or fluid by their rates of the constituents and motion style. In the present paper, we presented the characteristics of HF: the viscosity and the magnetization are respectively equivalent to those of other magnetic responsive fluids, MF and their solvents. For the structure, HF is soluble simultaneously with both diene and non-diene rubbers. The diene rubber such as Natural Rubber (NR) or Chloroprene (CR) has a role in the feasibility of electrolytic polymerization and the non-diene rubber such as silicon oil rubber (Q) has a role in defense against deterioration. Therefore, the electrolytically polymerized HF rubber by mixing NR, CR as well as Q is effective for the artificial soft and tactile skin. It is responsive to pressure and has optimal property on piezoelectricity in the case of the mixture of Ni particles as filler. HF is effective in the production of the artificial soft and tactile skin made of rubber.

橡胶颗粒沥青路面降噪性能与温度场计算研究

随着环保设计理念的深入,生态、绿色、低噪声的新型路面已经成为未来道路领域的发展方向。橡胶颗粒由于具有耐久性好、噪声值低、密实性强等优点,逐渐成为新型路面的研究重点。从降噪机理角度出发,确定了低噪声路面的最佳橡胶颗粒掺量为1.5%,同时从减振降噪、吸声降噪两个方面研究了空隙率、构造深度、轮胎垂直振动因素对降噪效果的影响。试验结果表明,掺加了橡胶颗粒的沥青路面路用性能完全满足设计标准要求,且降噪效果明显。同时通过数值模拟计算发现,橡胶颗粒沥青能起到隔热保温的作用,使得道路路面的基层和底基层等温度敏感结构不易受温度变化的影响,使其结构性质保持稳定。

实心轮胎温度场的有限元分析

应用ANSYS有限元分析软件模拟履带车辆实心橡胶轮胎在不同工作条件下的力学场,以模拟结果计算节点生热率,再将节点生热率导入合理假设的温度场有限元模型,模拟得到轮胎的温升规律。结果发现,轮胎的最高温度随着载荷、速度和损耗因子增大而提高,但随着导热系数增大而降低。

基于科学计量的天然橡胶学科领域前沿热点分析

当前天然橡胶产业持续低迷,追踪国际天然橡胶研究前沿热点对于我国天然橡胶产业发展和升级具有重要参考价值。本研究采用科学计量方法结合CiteSpace技术,对Web of Science数据库的天然橡胶文献进行共被引、共词和聚类分析,概述了该领域重要的基础文献,揭示其学科领域研究前沿和热点。结果表明,共探测出6个前沿热点,高度聚合在三大学科领域。其中,在化学与材料科学领域,领先优势十分明显,共遴选出4个前沿热点:(1)功能化改性石墨烯或氧化石墨/天然橡胶纳米复合材料;(2)生物基体/天然橡胶纳米复合材料;(3)弹性体或天然橡胶纳米复合材料的应变诱导结晶行为;(4)废旧橡胶的自修复与回收加工。在生物科学领域,遴选出1个前沿热点,即橡胶树基因组测序、橡胶生物合成路径与关键基因。在生态与环境科学领域,遴选出1个前沿热点,即橡胶林的扩张及其对生态环境的影响。高频和高突现关键词在三大学科呈现由多到少分布,反映了当前天然橡胶研究领域发展趋于多方向性,但其前沿热点相对集中在天然橡胶全产业链的下游。

硅橡胶电导特性对XLPE绝缘高压直流电缆中间接头内电场分布的影响

为改善交联聚乙烯(XLPE)绝缘高压直流电缆中间接头内的电场分布,通过添加纳米填料制备了用于制作电缆接头应力控制体的非线性硅橡胶复合材料。建立了高压直流电缆接头仿真模型,测试了各绝缘材料的电导特性,计算了电缆接头内的电场分布。研究结果表明,70℃时在各场强下未改性硅橡胶的电导率都小于高压直流电缆XLPE绝缘,故电缆接头内的最高场强点位于硅橡胶增强绝缘内,且最大场强远大于电缆本体绝缘的平均场强;以非线性硅橡胶做应力控制体增强绝缘时,超过一定场强后增强绝缘的电导率明显大于XLPE绝缘,保证了电缆接头内最高场强点永远位于XLPE绝缘内,且接近于平均场强。

深水立管柔性接头疲劳特性研究

为了分析不同温度条件下深水立管柔性接头的疲劳特性,在建立深水钢悬链线立管有限元模型的基础上,计算了柔性接头工作时承受的应力,将立管截面处的轴力和弯矩时间-历程曲线带入柔性接头有限元模型的参考点处,通过预定义不同的温度场得到柔性接头橡胶元件的应变规律;同时将橡胶元件的应变带入等效应变法建立的疲劳损伤模型中,得到柔性接头橡胶元件的疲劳寿命。分析结果表明,柔性接头橡胶元件的最大应变发生在最上层橡胶的一端,在设计时应增强第1层橡胶的强度以延长柔性接头的使用寿命;当温度场在80℃时橡胶元件疲劳寿命最短,在设计和使用柔性接头时应避免橡胶元件处在这一温度场范围内。所得结论对柔性接头的设计和使用具有指导意义。