POLYMERIZATION AND CHARACTERIZATION OF HIGH CONDUCTIVITY AND GOOD ADHENSION POLYPYRROLE FILMS FOR ELECTROMAGNETIC INTERFERENCE SHIELDING

• Published in: Chinese journal of polymer science Vol. 28; no. 6; pp. 923 - 930
• Main Authors: Qiao, Yong-sheng, Shen, La-zhen, Dou, Tao, Hu, Ming
• Format: Journal Article
• Language: English
• Published: Heidelberg Chinese Chemical Society and Institute of Chemistry, CAS 01.11.2010
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Industrial Chemistry/Chemical Engineering; Polymer Sciences; X射线光电子能谱; 化学聚合; 杂聚吡咯膜; 电磁屏蔽效能; 电磁干扰; 聚吡咯薄膜; 高电导率; EMI; Conductivity; Polypyrrole film; Adhesion
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-010-9175-x

Polypyrrole（PPy） shows a favorable application in the electromagnetic interference（EMI） shielding due to its good electrical conductivity and outstanding air stability.Conducting PPy films with high conductivity and good adhesion were successfully polymerized on the surface of insulating epoxy resin substrates using chemical polymerization.The factors affecting the properties of PPy films,such as the surface morphology,adhesion between PPy film and substrate,electrical conductivity,EMI shielding effectiveness（SE）,were investigated.The adhesion was improved significantly through a three-step surface pretreatment of epoxy resin substrates including removing impurities,roughening,and surface modification with silane coupling agent.An enhancement in the conductivity of PPy films of about one order of magnitude was achieved by adding dopant in FeCl_3 solution.The higher the conductivity,the better the shielding effectiveness.Taking sodium p-toluenesulfonate doped PPy film as example,EMI SE was in the practically useful range of about 30 dB over a wide frequency range from 30 MHz to 1500 MHz.The PPy film samples were characterized by scanning electron microscopy （SEM）,infrared spectra（IR）,X-ray photoelectron spectroscopy（XPS） and the flange coaxial transmission device.The fourpoint probe method was used to measure conductivity of PPy films.