preparation and characterization of phenolic resin/montmorillonite nanocomposite

phenolic resins have been widely used for selective high technology applications due to their excellent ablative properties, structural integrity and thermal stability that make them appropriate for thermal insulation materials, wood products industry, coatings, moulding compounds and composite materials. polymer layered silicate nanocomposites based on montmorillonite (mmt) have attracted a great deal of attention because of enhanced properties in mechanical, thermal, barrier and clarity properties without a significant increase in density, which is not possible with conventional fillers. phenolic resin/montmorillonite (cloisite 15a) nanocomposite was prepared by a combined route of solution blending and in-situ polymerization. theoptimized conditions for preparation of nanocomposite were achieved by evaluation of various processing parameters (mechanical mixer, high speed disperser and high energy ultrasonic source), mixing time (0.5, 1, 3, 10, 24, 48, 72, and 96 h) and different amounts of montmorillonite (5 and 10 weight percents of montmorillonite relative to resol). x-ray diffractometer and thermal gravimetric analyzer were used accordingly to show the degree of nanodispersions of organomontmorillonite in polymeric matrix and the effect of nanofiller on thermal stability of nanocomposite with respect to neatresol. the results of high energy ultrasonic source show that a nanocomposite of phenolic resin with 5 wt% montmorillonite displays the best dispersion of clay layers. thermal stability of nanocomposite was increased by 27% in comparison with neat resol.