Preparation and Evaluation of a Polyimide-Coated Ultrafine Gilt Molybdenum Wire and Its Knitted Mesh Used for Electromagnetic Reflectors.

Huiqi Shao,Xiaofei Ma,Fangbing Lin,Nanliang Chen,Jinhua Jiang,Shuang Li

doi:10.3390/polym9120734

Huiqi Shao, Xiaofei Ma + Show 4 more

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https://doi.org/10.3390/polym9120734

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Abstract

In this work, polyimide (PI) was coated onto an ultrafine gilt molybdenum wire in order to protect the gilt surface and prepare an electrically stable wire mesh material which can be widely used in space. The surface of the PI-coated gilt molybdenum wires was characterized using FTIR, SEM, and EDS. Factors such as temperature stability of the PI coating, mechanical properties of the PI-coated gilt molybdenum wires, contact resistance stability, and electromagnetic microwave reflectivity of the their knitted meshes were also investigated. The results indicate that the PI coating conformed uniformly to the surface of the gilt molybdenum wires. The prepared PI coating exhibited excellent temperature stability in the −196 to 300 °C range and could efficiently protect the gilt surface and improve the stability of contact resistance, while the reflection of its wire meshes showed only a slight decrease of 1.4% with the PI coating thickness of 3 μm for electromagnetic microwaves in the S band.

Highlights

Materials used in the advanced aerospace applications, such as antenna components, have to be capable of withstanding oxidation and radiation, while retaining satisfactory mechanical properties under an extremely complex environment
Co., Ltd. (Chengdu, China) and Northwest Institute for Non-ferrous Metal Research (Xi’an, China) was used in this research. This gilt molybdenum wire was produced through special process, so its flexibility and tensile properties can meet the requirements of a further knitting process [20]
After coated and heated on the coating device, the Polyamic acid (PAA) should have converted into PI

Summary

Introduction

Materials used in the advanced aerospace applications, such as antenna components, have to be capable of withstanding oxidation and radiation, while retaining satisfactory mechanical properties under an extremely complex environment. The excellent electrical conductivity, low coefficient of thermal expansion, and high-temperature stability make it suitable for extreme condition applications, such as in the rocket motors, satellite antennae, laser optics, and nanometer-scale electronics [2,3,4]. The electrical conductivity and passive intermodulation (PIM) products which may cause serious interference problems in antenna applications [5,6] can be greatly improved after gold plating. In the presence of the above described situations, a polymer coating treatment on the surface of gilt molybdenum wire can be a promising and efficient approach to solve these problems

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Conclusion