聚氨酯基磁流变胶制备及剪切流变特性

Preparation and shear rheological properties of polyurethane based magnetorheological gel

首先制备羰基铁粉质量分数为80%的聚氨酯基磁流变胶,并对其展开静态和动态剪切测试。结果表明:磁感应强度对MRG-80的力学性能影响显著,其影响分为缓慢增长、线性增长及稳定三个阶段。不同的磁感应强度下MRG-80具有剪切稀化特性,其流变力学特性可用Herschel-Bulkley描述;在960 mT下剪切屈服应力达到39.226 kPa。剪切应变幅值对材料储能模量影响强度受磁感应强度作用较大,线性粘弹性临界应变幅值随磁感应强度增强而增大。磁流变效应随着磁感应强度的增强而增强,最大磁流变效应MR可达到2141%;储能模量和损耗模量对频率的依赖性微弱。磁感应强度对MRG-80的法向应力的影响十分显著,随着磁感应强度的增强而增大。

The polyurethane based magnetorheological gel(MRG)with mass fraction of 80%was self-developed,and the static and dynamic shear tests were carried out,respectively.The results shown that the magnetic induction intensity has significant influence on the mechanical properties of MRG-80,and its effect was divided into three stages:slow growth,linear growth and stable,respectively.Materials have the characteristic of shear thinning under different magnetic induction,and its rheological properties can be described by Herschel-Bulkley.The shear yield stress reached 39.226 kPa under 960mT.The effect of shear strain amplitude on the storage modulus of material is greatly influenced by magnetic induction intensity.The linear viscoelastic strain amplitude increases with the increase of magnetic induction intensity.The magnetorheological effect increases with the enhancement of the magnetic induction intensity,and the maximum magnetorheological effect can reach 2141%.The dependence of storage and loss modulus on frequency was weak.The effect of magnetic induction intensity on the normal stress of material was very significant,which increases with the increase of magnetic induction intensity.