Thermal conductivity of natural rubber nanocomposites with hybrid fillers

Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H2O2) and distilled water(H2O). The functional groups on the surface of CNTs, changes in nanotube structure and morphology were characterized by Fourier transform infrared spectroscopy(FT-IR), Raman Spectroscopy, and transmission electron microscopy(TEM). It shows that hydroxyl(OH·) is successfully introduced. The surface defects of modified CNTs were obviously higher than those of original CNTs, and the degree of agglomeration was greatly reduced. Thermal conductivity of the composites was tested by protection heat flow meter method. Compared with unmodified CNTs/CB filling system, the thermal conductivity of hybrid composites is improved by an average of 5.8% with 1.5 phr(phr is parts per hundred rubber) of hydroxyl CNTs and 40 phr of CB filled. A three-dimensional heat conduction network composed of hydroxyl CNTs and CB, as observed by TEM, contributes to the good properties. Thermal conductivity of the hybrid composites increases as temperature rises. The mechanical properties of hybrid composites are also good with hydroxyl CNTs filled nanocomposites;the tensile strength, 100% and 300% tensile stress are improved by 10.1%, 22.4% and 26.2% respectively.

Hybrid Modified Rubber Powder and Its Application in Cement Mortar

This research focused on using the waste rubber powder as a kind of regenerate resources to improve the mechanical properties of cement mortar.The two kinds of hybrid modified rubber powder TRP and ATRP were prepared by sol-gel method and then used in cement mortar.The structures and properties of them were studied.It is shown that the nano Si-O-Si network is generated in TRP and ATRP networks and the hydrophilic group is grafted on the surface of ATRP.The mechanical properties of rubber-treated mortar（RTM） were tested and the microstructures of them were also studied.Compared to the mortars with unmodified rubber powders（RP）,NaOH treated rubber powder（SRP） and coupling agent treated rubber powder（CRP）,the RTM with ATRP has the highest compressive strength and flexural strength.The stress-strain curves shown that the peak of stress of RTM with ATRP is increased and indicated the higher compression deformation and toughness.It is found that the interfacial adhesion between the ATRP and cement mortar is increased distinctly by SEM,which results in enhanced ductility and mechanical properties of RTM with ATRP.

Hybrid Composite Based on Natural Rubber Reinforced with Short Fibers of the Triumfetta cordifolia/Saccharum officinarum L.: Performance Evaluation

This article contributes to the development of the new class of fully biodegradable “green” composites by combining fibers (natural/bio) with biodegradable resin. The vegetable fibers (Triumfetta cordifolia and sugarcane bagasse) treated with NaOH and bleached were incorporated into a natural rubber matrix. The influence of the fiber ratio on the physical properties, tensile strength and surface hardness of the hybrid composites was analyzed. The results show that the addition of fibers in the natural rubber matrix increases the water absorption capacity but gradually reduces it with increasing fiber ratio. The hybrid composites of the NRT50-50B proportions show the best tensile strengths at 20 phr and a shore A hardness of 43.7 at 30 phr. The combination of two fibers has improved the physical and mechanical properties of the hybrid composites which can be used in engineering applications.

冲击载荷下Hybrid Ⅲ假人颈部应力与应变

为研究对假人颈部软材料在冲击载荷下的动态力学响应,模拟了摆锤冲击工况和佩戴三点式安全带的Hybrid Ⅲ假人滑车正面碰撞工况。模拟中,基于验证的Hybrid Ⅲ 50百分位男子假人有限元模型,使用了非线性动态显示有限元仿真分析方法。在两种结构、两类载荷下,比较了颈部橡胶材料的局部应力和应变。结果表明:法规认证的颈部试验载荷工况比滑车碰撞工况严重。因此,为准确表征假人橡胶材料的力学行为,需要设计一种能够反映整车碰撞环境下假人颈部变形特征的材料试验;试验中,要求应变达到1.5,且应变率达到50 s-1;其应力状态包括单向拉伸/压缩、纯剪切、双向拉伸/压缩,以及体积压缩。

基于混合现实技术的智能装备向导应用

推进橡胶轮胎行业数字化转型,人机交互方便快捷、降低对操作人员能力要求是核心之一,本文根据橡胶机械设备的特点,基于MR(混合现实)技术的发展现状,分析MR技术可穿戴设备为橡胶机械领域的工作提供便捷,在应用场景中解决实际问题。阐述软控MR工业流管理系统,对员工工作内容指导,减少人力培训成本,提高工作效率,降低操作风险。并以此建立橡胶轮胎装备MR平台,推进MR技术在工业领域更多应用场景。

石墨烯改性白炭黑填料对天然橡胶性能的影响

白炭黑(主要成分为纳米SiO_(2),nano-SiO_(2))由于易于制取、绿色环保等优点,现被广泛用于橡胶补强中,但是白炭黑因为结构上的特点,导致其在橡胶中的分散性和补强能力比炭黑差。利用硅烷偶联剂改善白炭黑在橡胶中的分散性,并研究改性白炭黑和石墨烯(GE)的协同补强作用对天然橡胶(NR)的影响。使用助分散剂单宁酸(TA)修饰的石墨烯与使用硅烷偶联剂KH570改性的白炭黑通过迈克尔加成反应得到杂化填料(KS-TGE),与天然橡胶充分混合制得KS-TGE/NR复合材料。经过测试,白炭黑经过改性后不仅改善了其在橡胶中的分散性,并且其和石墨烯制得的杂化填料与天然橡胶共混后,天然橡胶的力学性能得到提升。与未改性的nano-SiO_(2)/NR相比,改性后的复合材料拉伸强度最高提升36.3%,断裂伸长率最高提升79.5%,此外KS-TGE/NR仍能保持优异的弹性和动态力学性能。

混掺纤维对再生橡胶混凝土抗冻融性能影响研究

再生橡胶混凝土作为一种绿色环保的新型建筑材料,通常被用于道路。在寒冷地区,抗冻融性能是路面结构重要的评价指标。文章采用不同的纤维掺入方式,研究了冻融循环作用下橡胶混凝土质量损失率和相对动弹模的变化规律。结果表明,单掺玻璃纤维(GF)能有效地减轻冻融循环作用下混凝土表面的侵蚀情况,质量损失率更小。钢纤维(SF)比GF更有效地减缓相对动弹模的下降速率。在150次冻融循环后,混掺纤维取得最大的相对动弹模。建立冻融损伤模型,预测冻融损伤的发展趋势,混掺纤维比单掺纤维能更好地提高混凝土的抗冻融性能。

炭黑-石墨烯杂化材料增强天然橡胶复合材料的性能研究

利用炭黑颗粒掺杂石墨烯得到炭黑-石墨烯纳米杂化粒子,经乳液复合制备炭黑-石墨烯/天然橡胶母胶,然后通过密炼制得炭黑-石墨烯/天然橡胶纳米复合材料,研究掺杂体系内炭黑用量对炭黑-石墨烯/天然橡胶复合材料的微观形貌、力学性能、压缩生热性能和耐磨性能的影响。结果表明:炭黑颗粒吸附在石墨烯表面,有效抑制了石墨烯的堆叠,从而减少了大片径多层石墨烯的形成,且随着炭黑用量的增大,石墨烯的裸露区域逐渐减少;当掺杂体系中炭黑/石墨烯用量比为10/1时,石墨烯在橡胶中的分散状态得到明显提升,复合材料的宏观力学性能、压缩生热性能和耐磨性能均明显改善。

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.

NBR/ORGANOMODIFIED BENTONITE INTERCALATED HYBRIDS AND THEIR EFFECTS ON THE TOUGHNESS OF PVC

Hybrids of intercalative nitrile-butadiene rubber/organomodified bentonite (NBR/OMB) were prepared by thelatex intercalation technique. Investigation of their mechanical properties and the microstructore of NBR/OMB showed thatthe organomodified bentonite is an effective toughener for NBR. Transmission electronic microscopy (TEM) and X-rnydiffraction (XRD) tests showed that the NBR macromolecule could be intercalated into the galleries of bentonite.Incorporation of NBR/OMB hybrids as tougheners into poly(vinyl chloride) (PVC) results in a substantial increase in theimpact strength of PVC, but little decrease in its tensile strength and flexural strength, compared to the unmodified PVC.

橡胶树杂交F_(1)代抗病种质鉴选及其抗病性分析

橡胶树棒孢霉落叶病(Corynespora leaf fall disease,CLFD)是全球主要植胶国最为严重的叶部病害之一,可造成严重的产量和经济损失,而抗病种质鉴选与创制利用是该病最为有效的防治策略。本研究对云研277-5×IAN 873、RRIC103×热研8-79和云研277-5×热垦525三个杂交组合的821份F_(1)代群体进行了抗棒孢霉落叶病的评价,明确了F_(1)代群体的抗病性水平,并从符合正态分布的2个杂交组合中筛选出32份候选F_(1)代单株进行芽接,再分别利用3个亚型的多主棒孢病菌和2种评价方法对候选F_(1)代无性系种苗进行抗病性复筛,最终获得5份抗病性较好的F_(1)代新种质。通过对5份抗病新种质防御酶活性的测定,以及抗病相关基因表达特性的分析,进一步证实了5份抗病新种质与多主棒孢病菌在侵染过程中的互作关系,明确了其在病原菌接种不同时间段的差异表达特征。本研究为橡胶树棒孢霉落叶病抗病性早期鉴选、抗病种质培育与创制利用提供了很好的种质材料和理论支撑。

新型列车侧墙内装板声学分析、优化及应用

为了开发与应用新型列车车体降噪内装结构,基于混合有限元-统计能量分析法对轨道车辆用新型橡胶泡棉夹芯板进行隔声与声辐射预测建模,并进行了实验验证,进而利用该模型分析了橡胶泡棉孔隙率与芯皮厚度比对其隔声性能、声辐射性能的影响规律,并通过敷设阻尼层优化了其声学性能。最后,在侧墙组合结构的声学设计中评价了其实际应用效果。结果表明:随着孔隙率的逐步下降,橡胶泡棉夹芯板隔声量上升趋势较为明显,而辐射声功率持续降低;随着芯皮厚度比的逐步提高,夹芯板隔声量呈略微上升趋势,辐射声功率则相应降低。在远离声源一侧的橡胶泡棉蒙皮外侧敷设阻尼层的效果最优,优化后夹芯板计权隔声量提高0.7 dB,总声功率级降低0.7 dB;相较于传统木质胶合板和铝蜂窝板,橡胶泡棉夹芯板相较于传统内装板材在结构隔声设计中具有轻量化优势。

硅橡胶/蒙脱土复合材料的制备、结构与性能

用溶液法和熔融法制备了硅橡胶／蒙脱土复合材料，测定了力学性能、耐热性、耐溶剂性等性能．并与通常采用的２＃气相法白碳黑填充补强硅橡胶的性能作了对比．实验表明，溶液法能使蒙脱土更好地分散在硅橡胶基体中，所得到的复合物的性能有了很大的提高，与２＃气相法白碳黑填充补强的硅橡胶性能相当．

橡胶丛枝病分子检测研究

感染橡胶丛枝病的长春花（菟丝子桥接），通过提取其总ＤＮＡ，以植原体（ｐｈｙｔｏｐｌａｓ－ｍａ）特异引物，进行 ＰＣＲ扩增，结果得到８６０ｂｐ的 ＤＮＡ片断，片断的大小与设计的相符。而健康长春花扩增得不到此片断。同样，将感染丛枝病的橡胶树总ＤＮＡ，进行ＰＣＲ扩增，结果与上述相同。该 ８６０ｂｐ片断经地高辛标记，核酸杂交结果显示，感染丛核病的橡胶树阳性反应强烈，健康橡胶树仅有微弱反应。

溶胶凝胶法在聚合物/无机纳米复合材料中的应用

本文对溶胶凝胶法在聚合物 无机纳米复合材料中的应用进行了综述。并对溶胶凝胶法在橡胶增强、光学仪器、功能化涂层以及其它领域中的应用进行了具体的讨论。指出溶胶凝胶过程工艺条件的优化以及分散介质范围的扩大将是溶胶凝胶法在聚合物 无机纳米复合材料中应用的发展方向。

废旧轮胎橡胶混合法改性沥青混合料的研究

运用包括湿法和干法两道工艺的混合法,在实验室成功开发了废旧轮胎橡胶改性沥青混合料.即先用细橡胶粉制备成橡胶沥青,然后在集料中加入粗橡胶粉拌制成废橡胶改性沥青混合料.试验结果表明,与类似级配的湿法工艺或干法工艺的改性沥青混合料相比,混合法改性沥青混合料显示出更加优良的高、低温性能,水稳定性完全满足要求,且消耗了相对多的废旧轮胎,达到了环保和工程双赢的目的.

功能化碳纳米管/炭黑复合橡胶性能研究

表面活性剂十二烷基苯磺酸钠对碳纳米管进行非共价键改性包覆,研究功能化碳纳米管与炭黑复合材料性能。结果表明,十二烷基苯磺酸钠与碳纳米管的石墨表面形成π-π堆叠,可有效阻止碳纳米管间的团聚。功能化碳纳米管/炭黑复合材料硫化时间缩短,加工性能得到改善,断裂伸长率提高66.1%,导热率提高8.4%。Payne效应和TEM表明,十二烷基苯磺酸钠包覆碳纳米管可有效改善碳纳米管在橡胶基体中分散,也改善了炭黑在复合材料中的分散。混合填料在橡胶基体均匀分散,加强了填料与基体的界面作用,建立良好的三维空间网络结构,使复合材料性能得到改善。

聚碳酸酯微粉／气相白炭黑杂化增强硅橡胶

利用磨盘形力化学反应器常温粉碎制备了聚碳酸酯(PC)微粉,在硅橡胶的常规补强体系中,引入PC微粉部分代替白炭黑,实现了对硅橡胶的杂化增强,在一定程度上改善了硅橡胶复合材料的力学性能。考察了PC微粉添加量、粒径以及表面处理白炭黑对硅橡胶复合材料力学性能的影响。结果表明,用PC微粉部分代替白炭黑,可以大幅度提高硅橡胶复合材料的断裂伸长率,从230％提高到最大320％左右,撕裂强度从12．3 kN／m提高到最大 14．6 kN／m,复合材料的硬度显著降低,从78降低至68,白炭黑经硅烷偶联剂处理后,硅橡胶复合材料的硬度减小为63。