Study On The Preparation And Evaluation Of Polymer-based Nano-powder Textile Composite Absorbing Material

Textile composite absorbing material is an important direction in the development of absorbing material nowadays.Using polymer as the matrix of absorbing material can improve the mechanical properties and flexibility of traditional absorbing material while maintaining the excellent absorbing property of traditional absorbing material.And to a certain extent,improve the absorbing performance of the material and expand the absorption band.CNT/Paraffin,Nano-Fe₃O₄/Paraffin and CNT/PU?polyurethane?were prepared and studied by using carbon nanotubes?CNT?and nano-ferric oxide?Nano-Fe₃O₄?as research objects.CNT/porous PU,Nano-Fe₃O₄/porous PU composite absorbing material and CNT/porous PU,Nano-Fe₃O₄/porous PU composite absorbing material with stainless steel yarn fabric and silver-plated fabric.In this paper,a series of researches on polymer-based nano-powder textile composite absorbing materials from preparation to structure and properties have been carried out systematically,mainly in the content of absorbing agent,the thickness of composite materials,the porous structure,and so on.The effects of thickness on the absorbing properties of composite fabrics and the testing methods of backing metal plate and non-lined metal plate are compared.The results show that:?1?The thickness and content of the composite absorbing materials are the main factors affecting the absorbing properties of the absorbing materials.?2?For the same sample,using the test method of backing metal plate,the measured return loss curve has a strong absorption peak.Although there is no absorption peak in the measured absorption curve,there is a certain absorption performance in the testing frequency band with the non-lined metal plate test method.?3?CNT/porous PU composite absorbing materials and Nano-Fe₃O₄/porous PU composite absorbing materials were prepared by vacuum freeze-drying method with the advantages of porous structure,the porous size of the two materials is about 7-9?m and the specific gravity is about 0.74 g/cm³.When the CNT content is 11%and the thickness is 8mm,when the frequency is 6.99GHz,the maximum absorption loss is-30.90dB,and the effective absorption bandwidth is 3.42GHz.When the Nano-Fe3O4 content is 5%and the thickness is 8mm,when the frequency is 17.45GHz,the maximum absorption loss is-21.72 dB,and the effective absorption bandwidth is 1.76GHz.?4?Under special circumstances,when the shielded object is not metal,the absorbing property of the material will decrease due to the synergetic effect of no metal layer.Therefore,it can be considered to combine with textile fabric with high reflection characteristics to improve the absorbing property.