Dynamic mechanical and rheological behavior of fluoroelastomer‐organoclay nanocomposites obtained from different preparation methods

A comparison among different preparation methods of fluoropolymer/clay nanocomposites based on a fluoroelastomeric matrix (Tecnoflon® P959) and organomodified montmorillonite clay (Cloisite®20A) is reported. While melt blending leads to intercalated structures, the X-ray diffraction patterns of solution blended nanocomposite suggest a better delamination of the clay platelets within the fluoropolymeric matrix (no diffraction peaks) if the solvent evaporation step is carried out very slowly (72 h) at ambient pressure and moderate temperature. For the solution blended-slow evaporation nanocomposite, dynamic mechanical analysis and dynamic rheological measurements show a strong increase in G′, a lower damping peak at Tg, and a pseudosolid like behavior in the terminal flow region, suggesting a likely exfoliation of the organomodified clay in the fluoroelastomeric matrix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4484–4487, 2006