各向异性不同含量羟基铁粉颗粒/磁性聚氨酯泡沫的可控力学和声学性能

Tunable mechanical and acoustic properties of anisotropic magnetic polyurethane foams with different carbonyl iron powder magnetic particle contents

聚氨酯泡沫(PUFs)被广泛应用于飞机、车辆和许多其他设施中的噪声控制。本文研究的磁性聚氨酯泡沫(MPUFs)是一种新型智能泡沫,其力学和声学特性可通过磁场控制。采用一步全水法制备了添加羟基铁粉颗粒的磁性聚氨酯泡沫(CIPs/MPUFs),在发泡过程中施加一定强度的磁场,磁颗粒沿着外加磁场方向排列成链状有序结构,得到各向异性磁性泡沫。在外加磁场作用下,CIPs/MPUFs内部磁性颗粒发生迁移,材料的力学和声学性能发生改变。实验研究了外加磁场对CIPs/MPUFs力学性能和吸声性能的影响。实验结果表明:在外加磁场条件下,CIPs/MPUFs的储能模量和损耗模量随磁性颗粒含量的增加而增加;CIPs/MPUFs的平均吸声系数变化幅度在1%~7%之间,当颗粒含量为5wt%、制备磁场为200 mT、测试施加1.5 A电流时,CIPs/MPUFs的平均吸声系数增加幅度最大,为6.5%。

Polyurethane foams(PUFs)have been widely used in aircrafts,vehicles and many other facilities for noise control.Magnetic polyurethane foams(MPUFs)are a new kind of smart foams whose mechanical and acoustic properties can be controlled by magnetic fields.In this paper,the anisotropic MPUFs was studied which were prepared by one-step full water foaming method with carbonyl iron powders(CIPs)magnetic particles.During the foaming process,the magnetic field was applied,and the CIPs were arrayed into a chain-like structure along the direction of the magnetic field.The movement of CIPs inside MPUFs under the magnetic field induces a change towards the mechanical and sound absorption properties.The influence of the external magnetic field on the mechanical properties and sound absorption properties of CIPs/MPUFs was investigated by experiments.The results show that under the magnetic field,the storage modulus and loss modulus of CIPs/MPUFs increase with the increase of CIPs content.The variation of the average sound absorption coefficient is between 1%and 7%.For the sample with 5wt%CIPs foamed under 200 mT,the increment of its average sound absorption coefficient under 1.5 A is 6.5%,which is maximum.