天然橡胶基磁流变弹性体的研制与表征  

Preparation and Characterization of Magnetorheological Elastomers Based on Natural Rubber

作　　者：陈琳[1] 龚兴龙[1] 孔庆合[1] 

机构地区：[1]中国科学技术大学力学和机械工程系

出　　处：《实验力学》2007年第3期372-378,共7页Journal of Experimental Mechanics

基　　金：国家自然科学基金(编号:10672154);高等学校博士学科点专项科研基金(编号:20050358010)

摘　　要：磁流变弹性体又称磁敏高弹体,是一种由高分子聚合物和磁性颗粒构成的新型智能材料,它的力学、电学、磁学等诸性能可以由外加磁场来控制,因此磁流变弹性体在舰船、振动控制等领域具有广泛的应用前景。但目前国际上研制的磁流变弹性体存在机械性能不够好和磁致效应不够强的问题,这制约了基于磁流变弹性体器件的设计和应用。为了制备出实用型磁流变弹性体,本文对其制备条件进行了研究,包括基体类型、预结构化时磁场强度和温度、增塑剂和磁性颗粒含量对磁流变弹性体磁致效应的影响。结果表明,以天然橡胶为基体的磁流变弹性体,在高于600mT外加磁感应强度下,当磁性颗粒含量为80%(质量比)时,剪切模量的相对增量达33%;而当磁性颗粒含量为90%时,剪切模量的绝对增量达4.5MPa。本文还对磁流变弹性体应用环境进行了实验研究,结果表明磁流变弹性体在小应变下显示出更强的磁致效应,而激励频率不改变材料的磁致模量。Magnetorheological Elastomers （MR Elastomers or MREs） are a class of novel smart material consisting of high molecular polymers and magnetic particles. The controllability of their mechanical, electrical, and magnetic properties through the applied magnetic fields has attracted increasing attentions and broad application prospects. However, the applications of conventional MREs are limited due to their insufficient MR effects and mechanical performances. This paper aims to optimize the fabrication method and to fabricate good natural rubber based MREs with high modulus by investigating the influences of a variety of fabrication conditions on the MREs performances, such as matrix type, field strength, temperature, plasticizer and iron particles. Among these factors, the content of iron particles plays the most important role in shear modulus. When the iron particle weight fraction is 80% and the applied magnetic field is above 600mT, the relative MR effect can reach 133%. If the iron weight fraction increases to 90%, the field-induced increment of shear modulus can reach 4. 5MPa. The effect of strain amplitude and driving frequency on viscoelastic properties of MREs is also analyzed. The shear modulus decreases with the increment of strain but is almost independent of the driving frequency.

关 键 词：磁流变弹性体 磁敏高弹体 磁致效应 磁致模量 机械性能 

分 类 号：TB381[一般工业技术—材料科学与工程]