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ABSTRACT PRODUCTION AND CHARACTERIZATION OF RESOL TYPE PHENOLIC RESIN / LAYERED SILICATE NANOCOMPOSITES TaSan, Cemal Cem M.S., Department of Metallurgical and Materials Engineering Supervisor: Assoc.Prof. Cevdet Kaynak April 2005 133 Pages Polymer / layered silicate (P/LS) nanocomposites belong to one of the most promising group of materials of the past few decades and most probably for the near future. Combining two of the most widely studied topics of material science: composite materials and nanotechnology / P/LS research have drawn great attention starting with the pioneering works of Toyota Research Group in 1980&rsquo / s. The research is now being carried out world wide / since the excellent properties of these new materials, which is achieved by using very low amounts of a cheap reinforcement material (clay), increases the interest on these materials everyday after. In this present study, the object was to investigate the production parameters of phenol formaldehyde based layered silicate nanocomposites. For this purpose, 14 different specimen groups were produced / using two different resol type phenolic resins (PF76 and PF76TD) as the matrix / and 9 different montmorillonite clays (Rheospan, Resadiye, Cloisite Na+, 10A, 15A, 20A, 25A, 30B, 94A) as the reinforcement phase. Initially the curing schedules for the available resins were experimentally determined. Then, a short and effective mixing procedure for the thermosetting resin and the montmorillonite clay was developed. The effects of several processing parameters / such as clay type, clay source, clay content, clay modification, resin type, resin cure type, cure cycle and mixing cycle were determined by X-ray Diffraction, Scanning Electron Microscopy and Mechanical Tests. Then, Transmission Electron Microscopy was used to investigate the level of intercalation and/or exfoliation of the layered silicates. Finally, Differential Scanning Calorimetry was also carried out to analyse thermal properties of the specimens. It was concluded that, a partially intercalated and/or exfoliated structure could be obtained in resol type phenolic resin based systems at very low clay contents (such as 0,5%) leading to remarkable increases in mechanical properties (e.g. 66% increase in fracture toughness).