磁场作用下磁性聚氨酯泡沫的力学和吸声性能分析

Analysis of mechanical and sound absorption properties of magnetic polyurethane foam under magnetic field

使用实验室自主研制的磁场设备,以添加了羰基铁粉的磁性聚氨酯泡沫为对象,研究磁场对磁性泡沫力学性能和低频吸声性能的影响,探寻智能磁性泡沫聚合物吸声性能和力学性能的可调性。首先采用一步全水发泡法,制备了质量分数为80%(质量分数)的各项异性与各向同性的磁性聚氨酯泡沫。接着基于美国TA流变仪,在交变的磁场作用下,测量这两种泡沫储能模量的变化。基于传递函数法,利用双通道阻抗管,测量在不同强度磁场下两种泡沫的吸声性能。实验结果发现,磁场的施加对各向异性与各向同性磁性聚氨酯泡沫的吸声性能影响有限,但其储能模量会随着磁场大小的绝对值增加而逐渐增加,经过时长为500 s,最大周期为0.5 T的交变磁场作用,各向同性聚氨酯泡沫的储能模量上升了14.6%,各项异性的上升了15.8%,这意味着磁场会增加磁性粒子短链之间的应力传递。

In order to explore the tunability of smart magnetic foam polymers in sound absorption and mechanical properties, the influence of magnetic field on the modulus properties and low frequency sound absorption properties of magnetic foam was studied by using custom-made magnetic device. First, isotropic and anisotropic magnetic polyurethane foam with mass fraction of 80wt% was prepared by one-step full water foaming method. Then, based on the TA rheometer, the changes of the storage modulus of the two kinds of foam were measured under the alternating magnetic field. Dual channel impedance tube and transfer function method were used to measure the sound absorption performance of two kinds of foams under different intensity magnetic fields. The experimental results show that the magnetic field exerted a limited influence on the sound absorption properties of anisotropic and isotropic magnetic polyurethane foam, but the storage modulus increased with the absolute value of the magnetic field. The storage modulus of isotropic polyurethane foam increased by 14.6% and the heterosexual increased by 15.8% after 500 s, when the maximum period was 0.5 T under the action of alternating magnetic field. This meant that the magnetic field would increase the stress transfer between short chains of magnetic particles.