Synthesis and electrorheological characteristics of microencapsulated polyaniline particles with melamine–formaldehyde resins

• Published in: Polymer (Guilford) Vol. 42; no. 19; pp. 8277 - 8283
• Main Authors: Lee, Y.H, Kim, C.A, Jang, W.H, Choi, H.J, Jhon, M.S
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2001; Elsevier
• Subjects: Applied sciences; Electrorheological fluid; Exact sciences and technology; Forms of application and semi-finished materials; Microencapsulation; Miscellaneous; Polyaniline; Polymer industry, paints, wood; Technology of polymers; Electrorheological fluid; Polyaniline; Microencapsulation; Viscoelasticity; Electrical conductivity; Electrical properties; Shear flow; Silicone oil; Condensation polymerization; Particle suspension; Experimental study; Thermal stability; Conducting polymers; Particle size distribution; Manufacturing process; Morphology; Coated particle; Melamine resin; Electric field effect; Flow curve; Aniline polymer
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/S0032-3861(01)00342-1

Polyaniline particles with low pH cannot be directly used in the electrorheological (ER) systems, since their emerald base form has a conductivity that is too high. Therefore, the pH of the polyaniline has been controlled to yield a lower conductivity. To improve the particle preparation method for polyaniline, which generates ER fluids with its semi-conducting characteristics, we synthesized microencapsulated polyaniline particles with melamine–formaldehyde (MF) resins. Microcapsules, containing polyaniline with a low pH as the core material, were prepared by polymerization of MF resin, which play the role of an insulator between the polyaniline particles. From rheological measurements, the yield stress of the ER fluid decreased with the increase of MF resin, and this effect enhanced as the applied electric field strength increased.