Preparation And Properties Of Electroless Copper Electromagnetic Shielding Material For Wood-Plastic

Wood-plastic composite,as a green and environment-friendly material,has the advantages of corrosion resistance,light weight and low cost,and is an ideal base material for studying functional materials.Electroless copper is combined with wood-plastic materials,so that a good metal coating is deposited on the surface of the materials,which endows the wood-plastic materials with electrical conductivity and electromagnetic shielding performance.In this study,the copper layer and the Cu-nano SiC composite coating were prepared on the basis of PVC-based wood-plastic composite without chromic acid coarsening.The research conclusions are as follows:1.Chromium-free roughening was carried out by nitric acid-hydrogen peroxide,and then the roughened substrate was dipped and modified by ethanol solution of silane coupling agent to obtain copper layer.The results show that after coarsening before electroless plating and dipping modification with KH550 silane coupling agent ethanol surface treatment solution,the surface roughness of the material increases,the micro-etching holes are evenly distributed and the density is increased.At the same time,with the increase of hydrophilic groups,the hydrophilicity of the material is greatly improved.After pre-plating treatment,the bonding force of the copper layer meets the quality standard of GB/T 1893.1-2013,and the amount of metal deposition and surface resistivity are improved.In the frequency range of 0～3000MHz（L land）,the electromagnetic shielding efficiency is 40.96 d B.2.The effects of pH value,temperature and component concentration of electroless copper solution on the properties of the coating were studied by single factor experiment.The results showed that Cu S0₄50 g/L,EDTA-2Na 40 g/L,Na KC₄H₄O₆30 g/L,HCHO 60 ml/L,pH 12.0 and temperature 60°C are the best eletcroless copper process.The obtained copper layer is pale pink.Through SEM and XRD analysis,the copper particles are closely arranged,there is no vacancy defect,and the coating completely covers the substrate.In the frequency range of 0～3000MHz（L land）,the electromagnetic shielding efficiency is 98.14 d B.3.Nano SiC was introduced,and Cu-nano SiC composite coating wasprepared by combining surfactant CTAB with ultrasonic dispersed phase.The ideal ultrasonic dispersion process is as follows:nano-SiC 2.0 g/L,CTAB 0.3 g/L,ultrasonic power600 W and ultrasonic time 15 min（ultrasonic interval time 15 s）.By SEM and XRD analysis,the composite coating structure is more uniform and dense,the nanoparticles are evenly distributed in the coating,the size of metal particles decreases,the deposition rate and conductivity are improved,and the wear of composite coating is0.207 g.In addition,with the increase of electroless times,the coating wear resistance and conductivity increase slightly,but the electromagnetic shielding efficiency does not change.