Synthesis and Dielectric Behavior of Polyaniline / Polyacrylic Acid Blends – Effect of Lithium Salt

• Main Authors: Tsz-Hung Ke, 柯賜鴻
• Other Authors: Sung-Nung Lee
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/48766768714660712801

碩士 === 輔仁大學 === 化學系 === 93 === High dielectric constant polymer composite materials are being sought by the electronic industry in response to the need for power- ground decoupling to secure integrity of high speed signals and reduce electromagnetic interference (EMI) radiated noise. On the other hand, fabrication of thin film capacitors on multi-chip modules is essential for downsizing circuit in high speed electronic system. Because of involving large amounts of capacitors, integration of capacitors is of much importance. Thus, developing an organic substrate-compatible high dielectric material is the major challenge of the integral capacitor technology. Polyaniline (PANI) has emerged as one of the most attracting conducting polymer, owing to its high polymerization yield, moderate electrical conductivity, good environmental stability and relative low cost. Nevertheless, some studies did observe that PANI and PANI / polymer blends are capable of obtaining a high dielectric constant. High dielectric constant polymer composites such as polyaniline / polyurethane (PANI/PU) and polyaniline / polyacrylic acid (PANI/PAA) have been synthesized in this lab recently. In addition, PANI has been considered as one of the most representative polymeric substance which are able to increase their conductivity as a result of internal transformation of polymeric network. Its insulating emeraldine base form (PANI-EB) may be converted into a conductive one, emeraldine salt form (PANI-ES) through protonation of the polymer. Emeraldine salt form is the most conductive form of PANI, while its conductivity can be reduced drastically as it is reverted back to PANI-EB form by adding appropriate base, such as lithium hydroxide. The present study incorporates various amount of lithium hydroxide into PANI / PAA polymeric system, and investigates the mechanism of electrical conduction of PANI by using impedance method. The thermal properties and morphological change are studied by DSC, TGA and SEM, respectively.